Trying to understand Microchip PIC16LF15344 peripheral pin selection for I2C





.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ height:90px;width:728px;box-sizing:border-box;
}







0















I have been reviewing the Microchip PIC16LF15344 datasheet for peripheral pin selection, and either I am reading it incorrectly or it appears to have errors and inconsistencies in the document. I would like to know if anyone else has used this device and can confirm my interpretation.



I'm trying to write code for a PIC16LF15344 to make use of the I2C interface. I have managed to write I2C code for a PIC16LF1822 that works fine, but I have so far been unable to get this to work on the PIC16LF15344, and there is some confusing documentation in the data sheet that I would like to get cleared up.



Here is a reference to the datasheet.



The pinout descriptions for the PIC16LF15344 shows that the I2C SDA function can be allocated to RC1 or RB6. Likewise, I2C SCL may be allocated to RC0 or RB4. But there is a note in Section 15.3 Bidirectional Pins as follows.




The I2C SCLx and SDAx functions can be remapped through PPS. However, only the RB1, RB2, RC3, and RC4 pints have the I2C and SMBus specific input buffers implemented (I2C mode disables INLVL and sets thresholds that are specific for I2C). If the SCLx or SDAx functions are mapped to some other pin (other than RB1, RB2, RC3, or RC4), the general purpose TTL or ST input buffers (as configured based on INLVL register setting) will be used instead. In most applications, it is therefore recommended only to map the SCLx and SDAx pin functions to the RB1, RB2, RC3 or RC4 pins.




The problem is not only does the note appear to conflict with the descriptions in the pin allocation tables, it also references pins RB1 and RB2, which don't appear anywhere in the pin allocation tables, i.e., they don't appear to exist for this PIC. I see similar footnote references to RB1 and RB2, but they are not documented anywhere in the body of the document or the tables.



Certainly this must be a documentation error, but I can find no current errata on the PIC16LF15324/44 datasheet to correct this. Am I reading this right?



I have tried configuring SCL and SDA with PPS to pins RC0 and RC1, since that is how they are wired on my PCB, but I can't get the I2C working yet using essentially the same software that I was using for the PIC16LF1822. The PPS default for EUSART TX2 and RX2 are RC0 and RC1. Does that mean I need to use TX2CKPPS and RX2DTPPS to move the EUSART assignments elsewhere before using SSP1CLKPPS and SSP1DATPPS to assign SCL and SDA to RC0 and RC1?



I will be investigating other potential problems with my PCB, but I want to get this straightened out before I submit another PCB for fab. I need to make some changes anyway, so I might just connect SCL and SDA to their PPS defaults in the next version and try again.



Here is the initialization code:



OSCFRQbits.HFFRQ = 0b011; // Set internal HF oscillator frequency to 8 MHz

WPUA   = 0b00111111;    // Enable all weak pull-up resistors on port A

WPUB   = 0b11110000;    // Enable all weak pull-up resistors on port B

WPUC   = 0b11111100;    // Enable all weak pull-up resistors on port C except

                        //    RC0 and RC1 to be used as I2C SCL and SDA

TRISA  = 0b00110000;    // Set RA4 and RA5 as inputs

ANSELA = 0b00110000;    // Set RA4 and RA5 to analog

TRISB  = 0b00110000;    // Set RB6 and RB7 as inputs

ANSELB = 0b11000000;    // Set RB6 and RB7 as analog

TRISC  = 0b11111011;    // Set RC0, RC1, RC3, RC4, RC5, RC6, and RC7 as inputs

ANSELC = 0b11111000;    // Set RC3, RC4, RC5, RC6, and RC7 as analog

TX2CKPPS   = 0b01100;   // Use RB4 for TX2

RX2DTPPS   = 0b01110;   // Use RB6 for RX2

SSP1CLKPPS = 0b10000;   // Use RC0 as SCL

SSP1DATPPS = 0b10001;   // Use RC1 as SDA

SSP1CON1 = 0b00100110;  // SSPEN enabled, WCOL no collision, SSPOV no overflow,

                        // CKP low hold, SSPM I2C slave 7-bit



SSP1CON2 = 0b00000000;  // ACKSTAT received, RCEN disabled, RSEN disabled, 

                        // ACKEN disabled, ACKDT acknowledge, SEN disabled, 

                        // GCEN disabled, PEN disabled



SSP1CON3 = 0b00000000;  // BOEN disabled, AHEN disabled, SBCDE disabled, 

                        // SDAHT 100 ns hold, ACKTIM ackseq, DHEN disabled, 

                        // PCIE disabled, SCIE disabled



SSP1STAT = 0x00;

SSP1BUF  = 0x00;

SSP1MSK  = 0xff;

SSP1ADD  = I2C_SLAVE_ADDR << 1;

PIR3bits.SSP1IF = 0;    // Clear the SSP Interrupt flag

PIE3bits.SSP1IE = 1;    // Enable SSP Interrupts

INTCONbits.GIE = 1;     // Enable global interrupts

INTCONbits.PEIE = 1;    // Enable peripheral interrupts





c embedded microcontroller pic microchip







share|improve this question

























  • I used the PPS on the PIC16F15324 and it works fine(maybe a little bit tricky). Could you show your code?

    – Mike
    Jan 3 at 9:27











  • Initialization code added as requested.

    – Zizumara
    Jan 4 at 21:05











  • Updated my answer with better PPS init code.

    – Dan1138
    Jan 5 at 3:42


















0















I have been reviewing the Microchip PIC16LF15344 datasheet for peripheral pin selection, and either I am reading it incorrectly or it appears to have errors and inconsistencies in the document. I would like to know if anyone else has used this device and can confirm my interpretation.



I'm trying to write code for a PIC16LF15344 to make use of the I2C interface. I have managed to write I2C code for a PIC16LF1822 that works fine, but I have so far been unable to get this to work on the PIC16LF15344, and there is some confusing documentation in the data sheet that I would like to get cleared up.



Here is a reference to the datasheet.



The pinout descriptions for the PIC16LF15344 shows that the I2C SDA function can be allocated to RC1 or RB6. Likewise, I2C SCL may be allocated to RC0 or RB4. But there is a note in Section 15.3 Bidirectional Pins as follows.




The I2C SCLx and SDAx functions can be remapped through PPS. However, only the RB1, RB2, RC3, and RC4 pints have the I2C and SMBus specific input buffers implemented (I2C mode disables INLVL and sets thresholds that are specific for I2C). If the SCLx or SDAx functions are mapped to some other pin (other than RB1, RB2, RC3, or RC4), the general purpose TTL or ST input buffers (as configured based on INLVL register setting) will be used instead. In most applications, it is therefore recommended only to map the SCLx and SDAx pin functions to the RB1, RB2, RC3 or RC4 pins.




The problem is not only does the note appear to conflict with the descriptions in the pin allocation tables, it also references pins RB1 and RB2, which don't appear anywhere in the pin allocation tables, i.e., they don't appear to exist for this PIC. I see similar footnote references to RB1 and RB2, but they are not documented anywhere in the body of the document or the tables.



Certainly this must be a documentation error, but I can find no current errata on the PIC16LF15324/44 datasheet to correct this. Am I reading this right?



I have tried configuring SCL and SDA with PPS to pins RC0 and RC1, since that is how they are wired on my PCB, but I can't get the I2C working yet using essentially the same software that I was using for the PIC16LF1822. The PPS default for EUSART TX2 and RX2 are RC0 and RC1. Does that mean I need to use TX2CKPPS and RX2DTPPS to move the EUSART assignments elsewhere before using SSP1CLKPPS and SSP1DATPPS to assign SCL and SDA to RC0 and RC1?



I will be investigating other potential problems with my PCB, but I want to get this straightened out before I submit another PCB for fab. I need to make some changes anyway, so I might just connect SCL and SDA to their PPS defaults in the next version and try again.



Here is the initialization code:



OSCFRQbits.HFFRQ = 0b011; // Set internal HF oscillator frequency to 8 MHz

WPUA   = 0b00111111;    // Enable all weak pull-up resistors on port A

WPUB   = 0b11110000;    // Enable all weak pull-up resistors on port B

WPUC   = 0b11111100;    // Enable all weak pull-up resistors on port C except

                        //    RC0 and RC1 to be used as I2C SCL and SDA

TRISA  = 0b00110000;    // Set RA4 and RA5 as inputs

ANSELA = 0b00110000;    // Set RA4 and RA5 to analog

TRISB  = 0b00110000;    // Set RB6 and RB7 as inputs

ANSELB = 0b11000000;    // Set RB6 and RB7 as analog

TRISC  = 0b11111011;    // Set RC0, RC1, RC3, RC4, RC5, RC6, and RC7 as inputs

ANSELC = 0b11111000;    // Set RC3, RC4, RC5, RC6, and RC7 as analog

TX2CKPPS   = 0b01100;   // Use RB4 for TX2

RX2DTPPS   = 0b01110;   // Use RB6 for RX2

SSP1CLKPPS = 0b10000;   // Use RC0 as SCL

SSP1DATPPS = 0b10001;   // Use RC1 as SDA

SSP1CON1 = 0b00100110;  // SSPEN enabled, WCOL no collision, SSPOV no overflow,

                        // CKP low hold, SSPM I2C slave 7-bit



SSP1CON2 = 0b00000000;  // ACKSTAT received, RCEN disabled, RSEN disabled, 

                        // ACKEN disabled, ACKDT acknowledge, SEN disabled, 

                        // GCEN disabled, PEN disabled



SSP1CON3 = 0b00000000;  // BOEN disabled, AHEN disabled, SBCDE disabled, 

                        // SDAHT 100 ns hold, ACKTIM ackseq, DHEN disabled, 

                        // PCIE disabled, SCIE disabled



SSP1STAT = 0x00;

SSP1BUF  = 0x00;

SSP1MSK  = 0xff;

SSP1ADD  = I2C_SLAVE_ADDR << 1;

PIR3bits.SSP1IF = 0;    // Clear the SSP Interrupt flag

PIE3bits.SSP1IE = 1;    // Enable SSP Interrupts

INTCONbits.GIE = 1;     // Enable global interrupts

INTCONbits.PEIE = 1;    // Enable peripheral interrupts





c embedded microcontroller pic microchip







share|improve this question

























  • I used the PPS on the PIC16F15324 and it works fine(maybe a little bit tricky). Could you show your code?

    – Mike
    Jan 3 at 9:27











  • Initialization code added as requested.

    – Zizumara
    Jan 4 at 21:05











  • Updated my answer with better PPS init code.

    – Dan1138
    Jan 5 at 3:42














0












0








0








I have been reviewing the Microchip PIC16LF15344 datasheet for peripheral pin selection, and either I am reading it incorrectly or it appears to have errors and inconsistencies in the document. I would like to know if anyone else has used this device and can confirm my interpretation.



I'm trying to write code for a PIC16LF15344 to make use of the I2C interface. I have managed to write I2C code for a PIC16LF1822 that works fine, but I have so far been unable to get this to work on the PIC16LF15344, and there is some confusing documentation in the data sheet that I would like to get cleared up.



Here is a reference to the datasheet.



The pinout descriptions for the PIC16LF15344 shows that the I2C SDA function can be allocated to RC1 or RB6. Likewise, I2C SCL may be allocated to RC0 or RB4. But there is a note in Section 15.3 Bidirectional Pins as follows.




The I2C SCLx and SDAx functions can be remapped through PPS. However, only the RB1, RB2, RC3, and RC4 pints have the I2C and SMBus specific input buffers implemented (I2C mode disables INLVL and sets thresholds that are specific for I2C). If the SCLx or SDAx functions are mapped to some other pin (other than RB1, RB2, RC3, or RC4), the general purpose TTL or ST input buffers (as configured based on INLVL register setting) will be used instead. In most applications, it is therefore recommended only to map the SCLx and SDAx pin functions to the RB1, RB2, RC3 or RC4 pins.




The problem is not only does the note appear to conflict with the descriptions in the pin allocation tables, it also references pins RB1 and RB2, which don't appear anywhere in the pin allocation tables, i.e., they don't appear to exist for this PIC. I see similar footnote references to RB1 and RB2, but they are not documented anywhere in the body of the document or the tables.



Certainly this must be a documentation error, but I can find no current errata on the PIC16LF15324/44 datasheet to correct this. Am I reading this right?



I have tried configuring SCL and SDA with PPS to pins RC0 and RC1, since that is how they are wired on my PCB, but I can't get the I2C working yet using essentially the same software that I was using for the PIC16LF1822. The PPS default for EUSART TX2 and RX2 are RC0 and RC1. Does that mean I need to use TX2CKPPS and RX2DTPPS to move the EUSART assignments elsewhere before using SSP1CLKPPS and SSP1DATPPS to assign SCL and SDA to RC0 and RC1?



I will be investigating other potential problems with my PCB, but I want to get this straightened out before I submit another PCB for fab. I need to make some changes anyway, so I might just connect SCL and SDA to their PPS defaults in the next version and try again.



Here is the initialization code:



OSCFRQbits.HFFRQ = 0b011; // Set internal HF oscillator frequency to 8 MHz

WPUA   = 0b00111111;    // Enable all weak pull-up resistors on port A

WPUB   = 0b11110000;    // Enable all weak pull-up resistors on port B

WPUC   = 0b11111100;    // Enable all weak pull-up resistors on port C except

                        //    RC0 and RC1 to be used as I2C SCL and SDA

TRISA  = 0b00110000;    // Set RA4 and RA5 as inputs

ANSELA = 0b00110000;    // Set RA4 and RA5 to analog

TRISB  = 0b00110000;    // Set RB6 and RB7 as inputs

ANSELB = 0b11000000;    // Set RB6 and RB7 as analog

TRISC  = 0b11111011;    // Set RC0, RC1, RC3, RC4, RC5, RC6, and RC7 as inputs

ANSELC = 0b11111000;    // Set RC3, RC4, RC5, RC6, and RC7 as analog

TX2CKPPS   = 0b01100;   // Use RB4 for TX2

RX2DTPPS   = 0b01110;   // Use RB6 for RX2

SSP1CLKPPS = 0b10000;   // Use RC0 as SCL

SSP1DATPPS = 0b10001;   // Use RC1 as SDA

SSP1CON1 = 0b00100110;  // SSPEN enabled, WCOL no collision, SSPOV no overflow,

                        // CKP low hold, SSPM I2C slave 7-bit



SSP1CON2 = 0b00000000;  // ACKSTAT received, RCEN disabled, RSEN disabled, 

                        // ACKEN disabled, ACKDT acknowledge, SEN disabled, 

                        // GCEN disabled, PEN disabled



SSP1CON3 = 0b00000000;  // BOEN disabled, AHEN disabled, SBCDE disabled, 

                        // SDAHT 100 ns hold, ACKTIM ackseq, DHEN disabled, 

                        // PCIE disabled, SCIE disabled



SSP1STAT = 0x00;

SSP1BUF  = 0x00;

SSP1MSK  = 0xff;

SSP1ADD  = I2C_SLAVE_ADDR << 1;

PIR3bits.SSP1IF = 0;    // Clear the SSP Interrupt flag

PIE3bits.SSP1IE = 1;    // Enable SSP Interrupts

INTCONbits.GIE = 1;     // Enable global interrupts

INTCONbits.PEIE = 1;    // Enable peripheral interrupts





c embedded microcontroller pic microchip







share|improve this question
















I have been reviewing the Microchip PIC16LF15344 datasheet for peripheral pin selection, and either I am reading it incorrectly or it appears to have errors and inconsistencies in the document. I would like to know if anyone else has used this device and can confirm my interpretation.



I'm trying to write code for a PIC16LF15344 to make use of the I2C interface. I have managed to write I2C code for a PIC16LF1822 that works fine, but I have so far been unable to get this to work on the PIC16LF15344, and there is some confusing documentation in the data sheet that I would like to get cleared up.



Here is a reference to the datasheet.



The pinout descriptions for the PIC16LF15344 shows that the I2C SDA function can be allocated to RC1 or RB6. Likewise, I2C SCL may be allocated to RC0 or RB4. But there is a note in Section 15.3 Bidirectional Pins as follows.




The I2C SCLx and SDAx functions can be remapped through PPS. However, only the RB1, RB2, RC3, and RC4 pints have the I2C and SMBus specific input buffers implemented (I2C mode disables INLVL and sets thresholds that are specific for I2C). If the SCLx or SDAx functions are mapped to some other pin (other than RB1, RB2, RC3, or RC4), the general purpose TTL or ST input buffers (as configured based on INLVL register setting) will be used instead. In most applications, it is therefore recommended only to map the SCLx and SDAx pin functions to the RB1, RB2, RC3 or RC4 pins.




The problem is not only does the note appear to conflict with the descriptions in the pin allocation tables, it also references pins RB1 and RB2, which don't appear anywhere in the pin allocation tables, i.e., they don't appear to exist for this PIC. I see similar footnote references to RB1 and RB2, but they are not documented anywhere in the body of the document or the tables.



Certainly this must be a documentation error, but I can find no current errata on the PIC16LF15324/44 datasheet to correct this. Am I reading this right?



I have tried configuring SCL and SDA with PPS to pins RC0 and RC1, since that is how they are wired on my PCB, but I can't get the I2C working yet using essentially the same software that I was using for the PIC16LF1822. The PPS default for EUSART TX2 and RX2 are RC0 and RC1. Does that mean I need to use TX2CKPPS and RX2DTPPS to move the EUSART assignments elsewhere before using SSP1CLKPPS and SSP1DATPPS to assign SCL and SDA to RC0 and RC1?



I will be investigating other potential problems with my PCB, but I want to get this straightened out before I submit another PCB for fab. I need to make some changes anyway, so I might just connect SCL and SDA to their PPS defaults in the next version and try again.



Here is the initialization code:



OSCFRQbits.HFFRQ = 0b011; // Set internal HF oscillator frequency to 8 MHz

WPUA   = 0b00111111;    // Enable all weak pull-up resistors on port A

WPUB   = 0b11110000;    // Enable all weak pull-up resistors on port B

WPUC   = 0b11111100;    // Enable all weak pull-up resistors on port C except

                        //    RC0 and RC1 to be used as I2C SCL and SDA

TRISA  = 0b00110000;    // Set RA4 and RA5 as inputs

ANSELA = 0b00110000;    // Set RA4 and RA5 to analog

TRISB  = 0b00110000;    // Set RB6 and RB7 as inputs

ANSELB = 0b11000000;    // Set RB6 and RB7 as analog

TRISC  = 0b11111011;    // Set RC0, RC1, RC3, RC4, RC5, RC6, and RC7 as inputs

ANSELC = 0b11111000;    // Set RC3, RC4, RC5, RC6, and RC7 as analog

TX2CKPPS   = 0b01100;   // Use RB4 for TX2

RX2DTPPS   = 0b01110;   // Use RB6 for RX2

SSP1CLKPPS = 0b10000;   // Use RC0 as SCL

SSP1DATPPS = 0b10001;   // Use RC1 as SDA

SSP1CON1 = 0b00100110;  // SSPEN enabled, WCOL no collision, SSPOV no overflow,

                        // CKP low hold, SSPM I2C slave 7-bit



SSP1CON2 = 0b00000000;  // ACKSTAT received, RCEN disabled, RSEN disabled, 

                        // ACKEN disabled, ACKDT acknowledge, SEN disabled, 

                        // GCEN disabled, PEN disabled



SSP1CON3 = 0b00000000;  // BOEN disabled, AHEN disabled, SBCDE disabled, 

                        // SDAHT 100 ns hold, ACKTIM ackseq, DHEN disabled, 

                        // PCIE disabled, SCIE disabled



SSP1STAT = 0x00;

SSP1BUF  = 0x00;

SSP1MSK  = 0xff;

SSP1ADD  = I2C_SLAVE_ADDR << 1;

PIR3bits.SSP1IF = 0;    // Clear the SSP Interrupt flag

PIE3bits.SSP1IE = 1;    // Enable SSP Interrupts

INTCONbits.GIE = 1;     // Enable global interrupts

INTCONbits.PEIE = 1;    // Enable peripheral interrupts





c embedded microcontroller pic microchip




c embedded microcontroller pic microchip






share|improve this question















share|improve this question













share|improve this question




share|improve this question








edited Jan 4 at 21:04







Zizumara

















asked Jan 3 at 3:33









ZizumaraZizumara

61




61













  • I used the PPS on the PIC16F15324 and it works fine(maybe a little bit tricky). Could you show your code?

    – Mike
    Jan 3 at 9:27











  • Initialization code added as requested.

    – Zizumara
    Jan 4 at 21:05











  • Updated my answer with better PPS init code.

    – Dan1138
    Jan 5 at 3:42



















  • I used the PPS on the PIC16F15324 and it works fine(maybe a little bit tricky). Could you show your code?

    – Mike
    Jan 3 at 9:27











  • Initialization code added as requested.

    – Zizumara
    Jan 4 at 21:05











  • Updated my answer with better PPS init code.

    – Dan1138
    Jan 5 at 3:42

















I used the PPS on the PIC16F15324 and it works fine(maybe a little bit tricky). Could you show your code?

– Mike
Jan 3 at 9:27





I used the PPS on the PIC16F15324 and it works fine(maybe a little bit tricky). Could you show your code?

– Mike
Jan 3 at 9:27













Initialization code added as requested.

– Zizumara
Jan 4 at 21:05





Initialization code added as requested.

– Zizumara
Jan 4 at 21:05













Updated my answer with better PPS init code.

– Dan1138
Jan 5 at 3:42





Updated my answer with better PPS init code.

– Dan1138
Jan 5 at 3:42












1 Answer
1






active

oldest

votes


















3














You likely have several issues to deal with.



All of the default I2C pins also have analog functionality too. Be sure that the ANSB or ANSC bits that are associated with the I2C pins are setup for digital operation.



While the power on reset selects the data sheet defaults for the I2C input pin assignments the I2C outputs by default are not assigned to any GPIO pin. You will need to place the I2C outputs for SCL and SDA in the correct PPS mapping registers.



Note that regardless of the I2C master or slave implementation both the input and output functions should be mapped to the same pin.



It would help to edit your question and post the code that you use to initialize the I2C pins and PPS mapping registers.



/*

 * File:   main.c

 *                             PIC16LF15354

 *                   +-------------:_:-------------+

 * 10K Pull-Up ->  1 : RE3/MCLR   ANB7/RX2/PGD/RB7 : 28 <> 

 *             <>  2 : RA0/ANA0   ANB6/TX2/PGC/RB6 : 27 <> RX2

 *             <>  3 : RA1/ANA1           ANB5/RB5 : 26 <>

 *             <>  4 : RA2/ANA2           ANB4/RB4 : 25 <> TX2

 *             <>  5 : RA3/ANA3           ANB3/RB3 : 24 <>

 *             <>  6 : RA4/ANA4      ANB2/SDA2/RB2 : 23 <>

 *             <>  7 : RA5/ANA5      ANB1/SCL2/RB1 : 22 <>

 *         GND ->  8 : VSS                ANB0/RB0 : 21 <>

 *             <>  9 : RA7/OSC1/ANA7           VDD : 20 <- 3v3

 *             <> 10 : RA6/OSC2/ANA6           VSS : 19 <- GND

 *        SCL1 <> 11 : RC0/ANC0       ANC7/RX1/RC7 : 18 <>

 *        SDA1 <> 12 : RC1/ANC1       ANC6/TX1/RC6 : 17 <>

 *             <> 13 : RC2/ANC2           ANC5/RC5 : 16 <> 

 *             <> 14 : RC3/SCL1/ANC3 ANC4/SDA1/RC4 : 15 <>

 *                   +-----------------------------:

 *                               DIP-28

 *

 * Created on January 4, 2019, 6:20 PM

 */





// PIC16LF15354 Configuration Bit Settings

#pragma config FEXTOSC = OFF    // External Oscillator mode selection bits (Oscillator not enabled)

#pragma config RSTOSC = HFINT32 // Power-up default value for COSC bits (HFINTOSC with OSCFRQ= 32 MHz and CDIV = 1:1)

#pragma config CLKOUTEN = OFF   // Clock Out Enable bit (CLKOUT function is disabled; i/o or oscillator function on OSC2)

#pragma config CSWEN = ON       // Clock Switch Enable bit (Writing to NOSC and NDIV is allowed)

#pragma config FCMEN = OFF      // Fail-Safe Clock Monitor Enable bit (FSCM timer disabled)

#pragma config MCLRE = ON       // Master Clear Enable bit (MCLR pin is Master Clear function)

#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)

#pragma config LPBOREN = OFF    // Low-Power BOR enable bit (ULPBOR disabled)

#pragma config BOREN = OFF      // Brown-out reset enable bits (Brown-out reset disabled)

#pragma config BORV = LO        // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (VBOR) set to 1.9V on LF, and 2.45V on F Devices)

#pragma config ZCD = OFF        // Zero-cross detect disable (Zero-cross detect circuit is disabled at POR.)

#pragma config PPS1WAY = OFF    // Peripheral Pin Select one-way control (The PPSLOCK bit can be set and cleared repeatedly by software)

#pragma config STVREN = ON      // Stack Overflow/Underflow Reset Enable bit (Stack Overflow or Underflow will cause a reset)

#pragma config WDTCPS = WDTCPS_31// WDT Period Select bits (Divider ratio 1:65536; software control of WDTPS)

#pragma config WDTE = SWDTEN    // WDT operating mode (WDT enabled/disabled by SWDTEN bit in WDTCON0)

#pragma config WDTCWS = WDTCWS_7// WDT Window Select bits (window always open (100%); software control; keyed access not required)

#pragma config WDTCCS = SC      // WDT input clock selector (Software Control)

#pragma config BBSIZE = BB512   // Boot Block Size Selection bits (512 words boot block size)

#pragma config BBEN = OFF       // Boot Block Enable bit (Boot Block disabled)

#pragma config SAFEN = OFF      // SAF Enable bit (SAF disabled)

#pragma config WRTAPP = OFF     // Application Block Write Protection bit (Application Block not write protected)

#pragma config WRTB = OFF       // Boot Block Write Protection bit (Boot Block not write protected)

#pragma config WRTC = OFF       // Configuration Register Write Protection bit (Configuration Register not write protected)

#pragma config WRTSAF = OFF     // Storage Area Flash Write Protection bit (SAF not write protected)

#pragma config LVP = OFF        // Low Voltage Programming Enable bit (High Voltage on MCLR/Vpp must be used for programming)

#pragma config CP = OFF         // UserNVM Program memory code protection bit (UserNVM code protection disabled)



#include <xc.h>



#define I2C_SLAVE_ADDR 0x00



void main(void) 

{

    WPUA   = 0b00111111;    // Enable all weak pull-up resistors on port A

    WPUB   = 0b11110000;    // Enable all weak pull-up resistors on port B

    WPUC   = 0b11111100;    // Enable all weak pull-up resistors on port C except

                            //    RC0 and RC1 to be used as I2C SCL and SDA

    TRISA  = 0b00110000;    // Set RA4 and RA5 as inputs

    ANSELA = 0b00110000;    // Set RA4 and RA5 to analog

    TRISB  = 0b00110000;    // Set RB6 and RB7 as inputs

    ANSELB = 0b11000000;    // Set RB6 and RB7 as analog

    TRISC  = 0b11111011;    // Set RC0, RC1, RC3, RC4, RC5, RC6, and RC7 as inputs

    ANSELC = 0b11111000;    // Set RC3, RC4, RC5, RC6, and RC7 as analog

#ifdef WRONG_WAY_TO_DO_PPS

    TX2CKPPS   = 0b01100;   // Use RB4 for TX2

    RX2DTPPS   = 0b01110;   // Use RB6 for RX2

    SSP1CLKPPS = 0b10000;   // Use RC0 as SCL

    SSP1DATPPS = 0b10001;   // Use RC1 as SDA

#else

    RB4PPS     = 0x11;      // Assign TX2 output  to RB4

    RX2DTPPS   = 0x0E;      // Assign RB6         to RX2 input

    RC0PPS     = 0x15;      // Assign SCL1 output to RC0

    SSP1CLKPPS = 0x10;      // Assign RC0         to SCL1 input

    RC1PPS     = 0x16;      // Assign SDA1 output to RC1

    SSP1DATPPS = 0x11;      // Assign RC1         to SDA1 input

#endif

    SSP1CON1 = 0b00100110;  // SSPEN enabled, WCOL no collision, SSPOV no overflow,

                            // CKP low hold, SSPM I2C slave 7-bit



    SSP1CON2 = 0b00000000;  // ACKSTAT received, RCEN disabled, RSEN disabled, 

                            // ACKEN disabled, ACKDT acknowledge, SEN disabled, 

                            // GCEN disabled, PEN disabled



    SSP1CON3 = 0b00000000;  // BOEN disabled, AHEN disabled, SBCDE disabled, 

                            // SDAHT 100 ns hold, ACKTIM ackseq, DHEN disabled, 

                            // PCIE disabled, SCIE disabled



    SSP1STAT = 0x00;

    SSP1BUF  = 0x00;

    SSP1MSK  = 0xff;

    SSP1ADD  = I2C_SLAVE_ADDR << 1;

    PIR3bits.SSP1IF = 0;    // Clear the SSP Interrupt flag

    PIE3bits.SSP1IE = 1;    // Enable SSP Interrupts

    INTCONbits.GIE = 1;     // Enable global interrupts

    INTCONbits.PEIE = 1;    // Enable peripheral interrupts

    /*

     * Embedded code never returns from main

     */

    for(;;)

    {



    }

}


The PPS is setup correctly but I do not know if the I2C initialization code is right.






share|improve this answer


























  • Initialization code added as requested.

    – Zizumara
    Jan 4 at 21:05











  • Thanks. I'll give that PPS configuration a try, but I now I understand that my PPS configuration couldn't have worked because the I2C outputs weren't going anywhere, which would explain why the master wasn't getting an ACK back from the PIC.

    – Zizumara
    Jan 6 at 4:54











  • I just tried those changes to the PPS configuration and my I2C interface is working now. Thanks again.

    – Zizumara
    Jan 6 at 6:52












Your Answer






StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f54015997%2ftrying-to-understand-microchip-pic16lf15344-peripheral-pin-selection-for-i2c%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























1 Answer
1






active

oldest

votes








1 Answer
1






active

oldest

votes









active

oldest

votes






active

oldest

votes









3














You likely have several issues to deal with.



All of the default I2C pins also have analog functionality too. Be sure that the ANSB or ANSC bits that are associated with the I2C pins are setup for digital operation.



While the power on reset selects the data sheet defaults for the I2C input pin assignments the I2C outputs by default are not assigned to any GPIO pin. You will need to place the I2C outputs for SCL and SDA in the correct PPS mapping registers.



Note that regardless of the I2C master or slave implementation both the input and output functions should be mapped to the same pin.



It would help to edit your question and post the code that you use to initialize the I2C pins and PPS mapping registers.



/*

 * File:   main.c

 *                             PIC16LF15354

 *                   +-------------:_:-------------+

 * 10K Pull-Up ->  1 : RE3/MCLR   ANB7/RX2/PGD/RB7 : 28 <> 

 *             <>  2 : RA0/ANA0   ANB6/TX2/PGC/RB6 : 27 <> RX2

 *             <>  3 : RA1/ANA1           ANB5/RB5 : 26 <>

 *             <>  4 : RA2/ANA2           ANB4/RB4 : 25 <> TX2

 *             <>  5 : RA3/ANA3           ANB3/RB3 : 24 <>

 *             <>  6 : RA4/ANA4      ANB2/SDA2/RB2 : 23 <>

 *             <>  7 : RA5/ANA5      ANB1/SCL2/RB1 : 22 <>

 *         GND ->  8 : VSS                ANB0/RB0 : 21 <>

 *             <>  9 : RA7/OSC1/ANA7           VDD : 20 <- 3v3

 *             <> 10 : RA6/OSC2/ANA6           VSS : 19 <- GND

 *        SCL1 <> 11 : RC0/ANC0       ANC7/RX1/RC7 : 18 <>

 *        SDA1 <> 12 : RC1/ANC1       ANC6/TX1/RC6 : 17 <>

 *             <> 13 : RC2/ANC2           ANC5/RC5 : 16 <> 

 *             <> 14 : RC3/SCL1/ANC3 ANC4/SDA1/RC4 : 15 <>

 *                   +-----------------------------:

 *                               DIP-28

 *

 * Created on January 4, 2019, 6:20 PM

 */





// PIC16LF15354 Configuration Bit Settings

#pragma config FEXTOSC = OFF    // External Oscillator mode selection bits (Oscillator not enabled)

#pragma config RSTOSC = HFINT32 // Power-up default value for COSC bits (HFINTOSC with OSCFRQ= 32 MHz and CDIV = 1:1)

#pragma config CLKOUTEN = OFF   // Clock Out Enable bit (CLKOUT function is disabled; i/o or oscillator function on OSC2)

#pragma config CSWEN = ON       // Clock Switch Enable bit (Writing to NOSC and NDIV is allowed)

#pragma config FCMEN = OFF      // Fail-Safe Clock Monitor Enable bit (FSCM timer disabled)

#pragma config MCLRE = ON       // Master Clear Enable bit (MCLR pin is Master Clear function)

#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)

#pragma config LPBOREN = OFF    // Low-Power BOR enable bit (ULPBOR disabled)

#pragma config BOREN = OFF      // Brown-out reset enable bits (Brown-out reset disabled)

#pragma config BORV = LO        // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (VBOR) set to 1.9V on LF, and 2.45V on F Devices)

#pragma config ZCD = OFF        // Zero-cross detect disable (Zero-cross detect circuit is disabled at POR.)

#pragma config PPS1WAY = OFF    // Peripheral Pin Select one-way control (The PPSLOCK bit can be set and cleared repeatedly by software)

#pragma config STVREN = ON      // Stack Overflow/Underflow Reset Enable bit (Stack Overflow or Underflow will cause a reset)

#pragma config WDTCPS = WDTCPS_31// WDT Period Select bits (Divider ratio 1:65536; software control of WDTPS)

#pragma config WDTE = SWDTEN    // WDT operating mode (WDT enabled/disabled by SWDTEN bit in WDTCON0)

#pragma config WDTCWS = WDTCWS_7// WDT Window Select bits (window always open (100%); software control; keyed access not required)

#pragma config WDTCCS = SC      // WDT input clock selector (Software Control)

#pragma config BBSIZE = BB512   // Boot Block Size Selection bits (512 words boot block size)

#pragma config BBEN = OFF       // Boot Block Enable bit (Boot Block disabled)

#pragma config SAFEN = OFF      // SAF Enable bit (SAF disabled)

#pragma config WRTAPP = OFF     // Application Block Write Protection bit (Application Block not write protected)

#pragma config WRTB = OFF       // Boot Block Write Protection bit (Boot Block not write protected)

#pragma config WRTC = OFF       // Configuration Register Write Protection bit (Configuration Register not write protected)

#pragma config WRTSAF = OFF     // Storage Area Flash Write Protection bit (SAF not write protected)

#pragma config LVP = OFF        // Low Voltage Programming Enable bit (High Voltage on MCLR/Vpp must be used for programming)

#pragma config CP = OFF         // UserNVM Program memory code protection bit (UserNVM code protection disabled)



#include <xc.h>



#define I2C_SLAVE_ADDR 0x00



void main(void) 

{

    WPUA   = 0b00111111;    // Enable all weak pull-up resistors on port A

    WPUB   = 0b11110000;    // Enable all weak pull-up resistors on port B

    WPUC   = 0b11111100;    // Enable all weak pull-up resistors on port C except

                            //    RC0 and RC1 to be used as I2C SCL and SDA

    TRISA  = 0b00110000;    // Set RA4 and RA5 as inputs

    ANSELA = 0b00110000;    // Set RA4 and RA5 to analog

    TRISB  = 0b00110000;    // Set RB6 and RB7 as inputs

    ANSELB = 0b11000000;    // Set RB6 and RB7 as analog

    TRISC  = 0b11111011;    // Set RC0, RC1, RC3, RC4, RC5, RC6, and RC7 as inputs

    ANSELC = 0b11111000;    // Set RC3, RC4, RC5, RC6, and RC7 as analog

#ifdef WRONG_WAY_TO_DO_PPS

    TX2CKPPS   = 0b01100;   // Use RB4 for TX2

    RX2DTPPS   = 0b01110;   // Use RB6 for RX2

    SSP1CLKPPS = 0b10000;   // Use RC0 as SCL

    SSP1DATPPS = 0b10001;   // Use RC1 as SDA

#else

    RB4PPS     = 0x11;      // Assign TX2 output  to RB4

    RX2DTPPS   = 0x0E;      // Assign RB6         to RX2 input

    RC0PPS     = 0x15;      // Assign SCL1 output to RC0

    SSP1CLKPPS = 0x10;      // Assign RC0         to SCL1 input

    RC1PPS     = 0x16;      // Assign SDA1 output to RC1

    SSP1DATPPS = 0x11;      // Assign RC1         to SDA1 input

#endif

    SSP1CON1 = 0b00100110;  // SSPEN enabled, WCOL no collision, SSPOV no overflow,

                            // CKP low hold, SSPM I2C slave 7-bit



    SSP1CON2 = 0b00000000;  // ACKSTAT received, RCEN disabled, RSEN disabled, 

                            // ACKEN disabled, ACKDT acknowledge, SEN disabled, 

                            // GCEN disabled, PEN disabled



    SSP1CON3 = 0b00000000;  // BOEN disabled, AHEN disabled, SBCDE disabled, 

                            // SDAHT 100 ns hold, ACKTIM ackseq, DHEN disabled, 

                            // PCIE disabled, SCIE disabled



    SSP1STAT = 0x00;

    SSP1BUF  = 0x00;

    SSP1MSK  = 0xff;

    SSP1ADD  = I2C_SLAVE_ADDR << 1;

    PIR3bits.SSP1IF = 0;    // Clear the SSP Interrupt flag

    PIE3bits.SSP1IE = 1;    // Enable SSP Interrupts

    INTCONbits.GIE = 1;     // Enable global interrupts

    INTCONbits.PEIE = 1;    // Enable peripheral interrupts

    /*

     * Embedded code never returns from main

     */

    for(;;)

    {



    }

}


The PPS is setup correctly but I do not know if the I2C initialization code is right.






share|improve this answer


























  • Initialization code added as requested.

    – Zizumara
    Jan 4 at 21:05











  • Thanks. I'll give that PPS configuration a try, but I now I understand that my PPS configuration couldn't have worked because the I2C outputs weren't going anywhere, which would explain why the master wasn't getting an ACK back from the PIC.

    – Zizumara
    Jan 6 at 4:54











  • I just tried those changes to the PPS configuration and my I2C interface is working now. Thanks again.

    – Zizumara
    Jan 6 at 6:52
















3














You likely have several issues to deal with.



All of the default I2C pins also have analog functionality too. Be sure that the ANSB or ANSC bits that are associated with the I2C pins are setup for digital operation.



While the power on reset selects the data sheet defaults for the I2C input pin assignments the I2C outputs by default are not assigned to any GPIO pin. You will need to place the I2C outputs for SCL and SDA in the correct PPS mapping registers.



Note that regardless of the I2C master or slave implementation both the input and output functions should be mapped to the same pin.



It would help to edit your question and post the code that you use to initialize the I2C pins and PPS mapping registers.



/*

 * File:   main.c

 *                             PIC16LF15354

 *                   +-------------:_:-------------+

 * 10K Pull-Up ->  1 : RE3/MCLR   ANB7/RX2/PGD/RB7 : 28 <> 

 *             <>  2 : RA0/ANA0   ANB6/TX2/PGC/RB6 : 27 <> RX2

 *             <>  3 : RA1/ANA1           ANB5/RB5 : 26 <>

 *             <>  4 : RA2/ANA2           ANB4/RB4 : 25 <> TX2

 *             <>  5 : RA3/ANA3           ANB3/RB3 : 24 <>

 *             <>  6 : RA4/ANA4      ANB2/SDA2/RB2 : 23 <>

 *             <>  7 : RA5/ANA5      ANB1/SCL2/RB1 : 22 <>

 *         GND ->  8 : VSS                ANB0/RB0 : 21 <>

 *             <>  9 : RA7/OSC1/ANA7           VDD : 20 <- 3v3

 *             <> 10 : RA6/OSC2/ANA6           VSS : 19 <- GND

 *        SCL1 <> 11 : RC0/ANC0       ANC7/RX1/RC7 : 18 <>

 *        SDA1 <> 12 : RC1/ANC1       ANC6/TX1/RC6 : 17 <>

 *             <> 13 : RC2/ANC2           ANC5/RC5 : 16 <> 

 *             <> 14 : RC3/SCL1/ANC3 ANC4/SDA1/RC4 : 15 <>

 *                   +-----------------------------:

 *                               DIP-28

 *

 * Created on January 4, 2019, 6:20 PM

 */





// PIC16LF15354 Configuration Bit Settings

#pragma config FEXTOSC = OFF    // External Oscillator mode selection bits (Oscillator not enabled)

#pragma config RSTOSC = HFINT32 // Power-up default value for COSC bits (HFINTOSC with OSCFRQ= 32 MHz and CDIV = 1:1)

#pragma config CLKOUTEN = OFF   // Clock Out Enable bit (CLKOUT function is disabled; i/o or oscillator function on OSC2)

#pragma config CSWEN = ON       // Clock Switch Enable bit (Writing to NOSC and NDIV is allowed)

#pragma config FCMEN = OFF      // Fail-Safe Clock Monitor Enable bit (FSCM timer disabled)

#pragma config MCLRE = ON       // Master Clear Enable bit (MCLR pin is Master Clear function)

#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)

#pragma config LPBOREN = OFF    // Low-Power BOR enable bit (ULPBOR disabled)

#pragma config BOREN = OFF      // Brown-out reset enable bits (Brown-out reset disabled)

#pragma config BORV = LO        // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (VBOR) set to 1.9V on LF, and 2.45V on F Devices)

#pragma config ZCD = OFF        // Zero-cross detect disable (Zero-cross detect circuit is disabled at POR.)

#pragma config PPS1WAY = OFF    // Peripheral Pin Select one-way control (The PPSLOCK bit can be set and cleared repeatedly by software)

#pragma config STVREN = ON      // Stack Overflow/Underflow Reset Enable bit (Stack Overflow or Underflow will cause a reset)

#pragma config WDTCPS = WDTCPS_31// WDT Period Select bits (Divider ratio 1:65536; software control of WDTPS)

#pragma config WDTE = SWDTEN    // WDT operating mode (WDT enabled/disabled by SWDTEN bit in WDTCON0)

#pragma config WDTCWS = WDTCWS_7// WDT Window Select bits (window always open (100%); software control; keyed access not required)

#pragma config WDTCCS = SC      // WDT input clock selector (Software Control)

#pragma config BBSIZE = BB512   // Boot Block Size Selection bits (512 words boot block size)

#pragma config BBEN = OFF       // Boot Block Enable bit (Boot Block disabled)

#pragma config SAFEN = OFF      // SAF Enable bit (SAF disabled)

#pragma config WRTAPP = OFF     // Application Block Write Protection bit (Application Block not write protected)

#pragma config WRTB = OFF       // Boot Block Write Protection bit (Boot Block not write protected)

#pragma config WRTC = OFF       // Configuration Register Write Protection bit (Configuration Register not write protected)

#pragma config WRTSAF = OFF     // Storage Area Flash Write Protection bit (SAF not write protected)

#pragma config LVP = OFF        // Low Voltage Programming Enable bit (High Voltage on MCLR/Vpp must be used for programming)

#pragma config CP = OFF         // UserNVM Program memory code protection bit (UserNVM code protection disabled)



#include <xc.h>



#define I2C_SLAVE_ADDR 0x00



void main(void) 

{

    WPUA   = 0b00111111;    // Enable all weak pull-up resistors on port A

    WPUB   = 0b11110000;    // Enable all weak pull-up resistors on port B

    WPUC   = 0b11111100;    // Enable all weak pull-up resistors on port C except

                            //    RC0 and RC1 to be used as I2C SCL and SDA

    TRISA  = 0b00110000;    // Set RA4 and RA5 as inputs

    ANSELA = 0b00110000;    // Set RA4 and RA5 to analog

    TRISB  = 0b00110000;    // Set RB6 and RB7 as inputs

    ANSELB = 0b11000000;    // Set RB6 and RB7 as analog

    TRISC  = 0b11111011;    // Set RC0, RC1, RC3, RC4, RC5, RC6, and RC7 as inputs

    ANSELC = 0b11111000;    // Set RC3, RC4, RC5, RC6, and RC7 as analog

#ifdef WRONG_WAY_TO_DO_PPS

    TX2CKPPS   = 0b01100;   // Use RB4 for TX2

    RX2DTPPS   = 0b01110;   // Use RB6 for RX2

    SSP1CLKPPS = 0b10000;   // Use RC0 as SCL

    SSP1DATPPS = 0b10001;   // Use RC1 as SDA

#else

    RB4PPS     = 0x11;      // Assign TX2 output  to RB4

    RX2DTPPS   = 0x0E;      // Assign RB6         to RX2 input

    RC0PPS     = 0x15;      // Assign SCL1 output to RC0

    SSP1CLKPPS = 0x10;      // Assign RC0         to SCL1 input

    RC1PPS     = 0x16;      // Assign SDA1 output to RC1

    SSP1DATPPS = 0x11;      // Assign RC1         to SDA1 input

#endif

    SSP1CON1 = 0b00100110;  // SSPEN enabled, WCOL no collision, SSPOV no overflow,

                            // CKP low hold, SSPM I2C slave 7-bit



    SSP1CON2 = 0b00000000;  // ACKSTAT received, RCEN disabled, RSEN disabled, 

                            // ACKEN disabled, ACKDT acknowledge, SEN disabled, 

                            // GCEN disabled, PEN disabled



    SSP1CON3 = 0b00000000;  // BOEN disabled, AHEN disabled, SBCDE disabled, 

                            // SDAHT 100 ns hold, ACKTIM ackseq, DHEN disabled, 

                            // PCIE disabled, SCIE disabled



    SSP1STAT = 0x00;

    SSP1BUF  = 0x00;

    SSP1MSK  = 0xff;

    SSP1ADD  = I2C_SLAVE_ADDR << 1;

    PIR3bits.SSP1IF = 0;    // Clear the SSP Interrupt flag

    PIE3bits.SSP1IE = 1;    // Enable SSP Interrupts

    INTCONbits.GIE = 1;     // Enable global interrupts

    INTCONbits.PEIE = 1;    // Enable peripheral interrupts

    /*

     * Embedded code never returns from main

     */

    for(;;)

    {



    }

}


The PPS is setup correctly but I do not know if the I2C initialization code is right.






share|improve this answer


























  • Initialization code added as requested.

    – Zizumara
    Jan 4 at 21:05











  • Thanks. I'll give that PPS configuration a try, but I now I understand that my PPS configuration couldn't have worked because the I2C outputs weren't going anywhere, which would explain why the master wasn't getting an ACK back from the PIC.

    – Zizumara
    Jan 6 at 4:54











  • I just tried those changes to the PPS configuration and my I2C interface is working now. Thanks again.

    – Zizumara
    Jan 6 at 6:52














3












3








3







You likely have several issues to deal with.



All of the default I2C pins also have analog functionality too. Be sure that the ANSB or ANSC bits that are associated with the I2C pins are setup for digital operation.



While the power on reset selects the data sheet defaults for the I2C input pin assignments the I2C outputs by default are not assigned to any GPIO pin. You will need to place the I2C outputs for SCL and SDA in the correct PPS mapping registers.



Note that regardless of the I2C master or slave implementation both the input and output functions should be mapped to the same pin.



It would help to edit your question and post the code that you use to initialize the I2C pins and PPS mapping registers.



/*

 * File:   main.c

 *                             PIC16LF15354

 *                   +-------------:_:-------------+

 * 10K Pull-Up ->  1 : RE3/MCLR   ANB7/RX2/PGD/RB7 : 28 <> 

 *             <>  2 : RA0/ANA0   ANB6/TX2/PGC/RB6 : 27 <> RX2

 *             <>  3 : RA1/ANA1           ANB5/RB5 : 26 <>

 *             <>  4 : RA2/ANA2           ANB4/RB4 : 25 <> TX2

 *             <>  5 : RA3/ANA3           ANB3/RB3 : 24 <>

 *             <>  6 : RA4/ANA4      ANB2/SDA2/RB2 : 23 <>

 *             <>  7 : RA5/ANA5      ANB1/SCL2/RB1 : 22 <>

 *         GND ->  8 : VSS                ANB0/RB0 : 21 <>

 *             <>  9 : RA7/OSC1/ANA7           VDD : 20 <- 3v3

 *             <> 10 : RA6/OSC2/ANA6           VSS : 19 <- GND

 *        SCL1 <> 11 : RC0/ANC0       ANC7/RX1/RC7 : 18 <>

 *        SDA1 <> 12 : RC1/ANC1       ANC6/TX1/RC6 : 17 <>

 *             <> 13 : RC2/ANC2           ANC5/RC5 : 16 <> 

 *             <> 14 : RC3/SCL1/ANC3 ANC4/SDA1/RC4 : 15 <>

 *                   +-----------------------------:

 *                               DIP-28

 *

 * Created on January 4, 2019, 6:20 PM

 */





// PIC16LF15354 Configuration Bit Settings

#pragma config FEXTOSC = OFF    // External Oscillator mode selection bits (Oscillator not enabled)

#pragma config RSTOSC = HFINT32 // Power-up default value for COSC bits (HFINTOSC with OSCFRQ= 32 MHz and CDIV = 1:1)

#pragma config CLKOUTEN = OFF   // Clock Out Enable bit (CLKOUT function is disabled; i/o or oscillator function on OSC2)

#pragma config CSWEN = ON       // Clock Switch Enable bit (Writing to NOSC and NDIV is allowed)

#pragma config FCMEN = OFF      // Fail-Safe Clock Monitor Enable bit (FSCM timer disabled)

#pragma config MCLRE = ON       // Master Clear Enable bit (MCLR pin is Master Clear function)

#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)

#pragma config LPBOREN = OFF    // Low-Power BOR enable bit (ULPBOR disabled)

#pragma config BOREN = OFF      // Brown-out reset enable bits (Brown-out reset disabled)

#pragma config BORV = LO        // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (VBOR) set to 1.9V on LF, and 2.45V on F Devices)

#pragma config ZCD = OFF        // Zero-cross detect disable (Zero-cross detect circuit is disabled at POR.)

#pragma config PPS1WAY = OFF    // Peripheral Pin Select one-way control (The PPSLOCK bit can be set and cleared repeatedly by software)

#pragma config STVREN = ON      // Stack Overflow/Underflow Reset Enable bit (Stack Overflow or Underflow will cause a reset)

#pragma config WDTCPS = WDTCPS_31// WDT Period Select bits (Divider ratio 1:65536; software control of WDTPS)

#pragma config WDTE = SWDTEN    // WDT operating mode (WDT enabled/disabled by SWDTEN bit in WDTCON0)

#pragma config WDTCWS = WDTCWS_7// WDT Window Select bits (window always open (100%); software control; keyed access not required)

#pragma config WDTCCS = SC      // WDT input clock selector (Software Control)

#pragma config BBSIZE = BB512   // Boot Block Size Selection bits (512 words boot block size)

#pragma config BBEN = OFF       // Boot Block Enable bit (Boot Block disabled)

#pragma config SAFEN = OFF      // SAF Enable bit (SAF disabled)

#pragma config WRTAPP = OFF     // Application Block Write Protection bit (Application Block not write protected)

#pragma config WRTB = OFF       // Boot Block Write Protection bit (Boot Block not write protected)

#pragma config WRTC = OFF       // Configuration Register Write Protection bit (Configuration Register not write protected)

#pragma config WRTSAF = OFF     // Storage Area Flash Write Protection bit (SAF not write protected)

#pragma config LVP = OFF        // Low Voltage Programming Enable bit (High Voltage on MCLR/Vpp must be used for programming)

#pragma config CP = OFF         // UserNVM Program memory code protection bit (UserNVM code protection disabled)



#include <xc.h>



#define I2C_SLAVE_ADDR 0x00



void main(void) 

{

    WPUA   = 0b00111111;    // Enable all weak pull-up resistors on port A

    WPUB   = 0b11110000;    // Enable all weak pull-up resistors on port B

    WPUC   = 0b11111100;    // Enable all weak pull-up resistors on port C except

                            //    RC0 and RC1 to be used as I2C SCL and SDA

    TRISA  = 0b00110000;    // Set RA4 and RA5 as inputs

    ANSELA = 0b00110000;    // Set RA4 and RA5 to analog

    TRISB  = 0b00110000;    // Set RB6 and RB7 as inputs

    ANSELB = 0b11000000;    // Set RB6 and RB7 as analog

    TRISC  = 0b11111011;    // Set RC0, RC1, RC3, RC4, RC5, RC6, and RC7 as inputs

    ANSELC = 0b11111000;    // Set RC3, RC4, RC5, RC6, and RC7 as analog

#ifdef WRONG_WAY_TO_DO_PPS

    TX2CKPPS   = 0b01100;   // Use RB4 for TX2

    RX2DTPPS   = 0b01110;   // Use RB6 for RX2

    SSP1CLKPPS = 0b10000;   // Use RC0 as SCL

    SSP1DATPPS = 0b10001;   // Use RC1 as SDA

#else

    RB4PPS     = 0x11;      // Assign TX2 output  to RB4

    RX2DTPPS   = 0x0E;      // Assign RB6         to RX2 input

    RC0PPS     = 0x15;      // Assign SCL1 output to RC0

    SSP1CLKPPS = 0x10;      // Assign RC0         to SCL1 input

    RC1PPS     = 0x16;      // Assign SDA1 output to RC1

    SSP1DATPPS = 0x11;      // Assign RC1         to SDA1 input

#endif

    SSP1CON1 = 0b00100110;  // SSPEN enabled, WCOL no collision, SSPOV no overflow,

                            // CKP low hold, SSPM I2C slave 7-bit



    SSP1CON2 = 0b00000000;  // ACKSTAT received, RCEN disabled, RSEN disabled, 

                            // ACKEN disabled, ACKDT acknowledge, SEN disabled, 

                            // GCEN disabled, PEN disabled



    SSP1CON3 = 0b00000000;  // BOEN disabled, AHEN disabled, SBCDE disabled, 

                            // SDAHT 100 ns hold, ACKTIM ackseq, DHEN disabled, 

                            // PCIE disabled, SCIE disabled



    SSP1STAT = 0x00;

    SSP1BUF  = 0x00;

    SSP1MSK  = 0xff;

    SSP1ADD  = I2C_SLAVE_ADDR << 1;

    PIR3bits.SSP1IF = 0;    // Clear the SSP Interrupt flag

    PIE3bits.SSP1IE = 1;    // Enable SSP Interrupts

    INTCONbits.GIE = 1;     // Enable global interrupts

    INTCONbits.PEIE = 1;    // Enable peripheral interrupts

    /*

     * Embedded code never returns from main

     */

    for(;;)

    {



    }

}


The PPS is setup correctly but I do not know if the I2C initialization code is right.






share|improve this answer















You likely have several issues to deal with.



All of the default I2C pins also have analog functionality too. Be sure that the ANSB or ANSC bits that are associated with the I2C pins are setup for digital operation.



While the power on reset selects the data sheet defaults for the I2C input pin assignments the I2C outputs by default are not assigned to any GPIO pin. You will need to place the I2C outputs for SCL and SDA in the correct PPS mapping registers.



Note that regardless of the I2C master or slave implementation both the input and output functions should be mapped to the same pin.



It would help to edit your question and post the code that you use to initialize the I2C pins and PPS mapping registers.



/*

 * File:   main.c

 *                             PIC16LF15354

 *                   +-------------:_:-------------+

 * 10K Pull-Up ->  1 : RE3/MCLR   ANB7/RX2/PGD/RB7 : 28 <> 

 *             <>  2 : RA0/ANA0   ANB6/TX2/PGC/RB6 : 27 <> RX2

 *             <>  3 : RA1/ANA1           ANB5/RB5 : 26 <>

 *             <>  4 : RA2/ANA2           ANB4/RB4 : 25 <> TX2

 *             <>  5 : RA3/ANA3           ANB3/RB3 : 24 <>

 *             <>  6 : RA4/ANA4      ANB2/SDA2/RB2 : 23 <>

 *             <>  7 : RA5/ANA5      ANB1/SCL2/RB1 : 22 <>

 *         GND ->  8 : VSS                ANB0/RB0 : 21 <>

 *             <>  9 : RA7/OSC1/ANA7           VDD : 20 <- 3v3

 *             <> 10 : RA6/OSC2/ANA6           VSS : 19 <- GND

 *        SCL1 <> 11 : RC0/ANC0       ANC7/RX1/RC7 : 18 <>

 *        SDA1 <> 12 : RC1/ANC1       ANC6/TX1/RC6 : 17 <>

 *             <> 13 : RC2/ANC2           ANC5/RC5 : 16 <> 

 *             <> 14 : RC3/SCL1/ANC3 ANC4/SDA1/RC4 : 15 <>

 *                   +-----------------------------:

 *                               DIP-28

 *

 * Created on January 4, 2019, 6:20 PM

 */





// PIC16LF15354 Configuration Bit Settings

#pragma config FEXTOSC = OFF    // External Oscillator mode selection bits (Oscillator not enabled)

#pragma config RSTOSC = HFINT32 // Power-up default value for COSC bits (HFINTOSC with OSCFRQ= 32 MHz and CDIV = 1:1)

#pragma config CLKOUTEN = OFF   // Clock Out Enable bit (CLKOUT function is disabled; i/o or oscillator function on OSC2)

#pragma config CSWEN = ON       // Clock Switch Enable bit (Writing to NOSC and NDIV is allowed)

#pragma config FCMEN = OFF      // Fail-Safe Clock Monitor Enable bit (FSCM timer disabled)

#pragma config MCLRE = ON       // Master Clear Enable bit (MCLR pin is Master Clear function)

#pragma config PWRTE = OFF      // Power-up Timer Enable bit (PWRT disabled)

#pragma config LPBOREN = OFF    // Low-Power BOR enable bit (ULPBOR disabled)

#pragma config BOREN = OFF      // Brown-out reset enable bits (Brown-out reset disabled)

#pragma config BORV = LO        // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (VBOR) set to 1.9V on LF, and 2.45V on F Devices)

#pragma config ZCD = OFF        // Zero-cross detect disable (Zero-cross detect circuit is disabled at POR.)

#pragma config PPS1WAY = OFF    // Peripheral Pin Select one-way control (The PPSLOCK bit can be set and cleared repeatedly by software)

#pragma config STVREN = ON      // Stack Overflow/Underflow Reset Enable bit (Stack Overflow or Underflow will cause a reset)

#pragma config WDTCPS = WDTCPS_31// WDT Period Select bits (Divider ratio 1:65536; software control of WDTPS)

#pragma config WDTE = SWDTEN    // WDT operating mode (WDT enabled/disabled by SWDTEN bit in WDTCON0)

#pragma config WDTCWS = WDTCWS_7// WDT Window Select bits (window always open (100%); software control; keyed access not required)

#pragma config WDTCCS = SC      // WDT input clock selector (Software Control)

#pragma config BBSIZE = BB512   // Boot Block Size Selection bits (512 words boot block size)

#pragma config BBEN = OFF       // Boot Block Enable bit (Boot Block disabled)

#pragma config SAFEN = OFF      // SAF Enable bit (SAF disabled)

#pragma config WRTAPP = OFF     // Application Block Write Protection bit (Application Block not write protected)

#pragma config WRTB = OFF       // Boot Block Write Protection bit (Boot Block not write protected)

#pragma config WRTC = OFF       // Configuration Register Write Protection bit (Configuration Register not write protected)

#pragma config WRTSAF = OFF     // Storage Area Flash Write Protection bit (SAF not write protected)

#pragma config LVP = OFF        // Low Voltage Programming Enable bit (High Voltage on MCLR/Vpp must be used for programming)

#pragma config CP = OFF         // UserNVM Program memory code protection bit (UserNVM code protection disabled)



#include <xc.h>



#define I2C_SLAVE_ADDR 0x00



void main(void) 

{

    WPUA   = 0b00111111;    // Enable all weak pull-up resistors on port A

    WPUB   = 0b11110000;    // Enable all weak pull-up resistors on port B

    WPUC   = 0b11111100;    // Enable all weak pull-up resistors on port C except

                            //    RC0 and RC1 to be used as I2C SCL and SDA

    TRISA  = 0b00110000;    // Set RA4 and RA5 as inputs

    ANSELA = 0b00110000;    // Set RA4 and RA5 to analog

    TRISB  = 0b00110000;    // Set RB6 and RB7 as inputs

    ANSELB = 0b11000000;    // Set RB6 and RB7 as analog

    TRISC  = 0b11111011;    // Set RC0, RC1, RC3, RC4, RC5, RC6, and RC7 as inputs

    ANSELC = 0b11111000;    // Set RC3, RC4, RC5, RC6, and RC7 as analog

#ifdef WRONG_WAY_TO_DO_PPS

    TX2CKPPS   = 0b01100;   // Use RB4 for TX2

    RX2DTPPS   = 0b01110;   // Use RB6 for RX2

    SSP1CLKPPS = 0b10000;   // Use RC0 as SCL

    SSP1DATPPS = 0b10001;   // Use RC1 as SDA

#else

    RB4PPS     = 0x11;      // Assign TX2 output  to RB4

    RX2DTPPS   = 0x0E;      // Assign RB6         to RX2 input

    RC0PPS     = 0x15;      // Assign SCL1 output to RC0

    SSP1CLKPPS = 0x10;      // Assign RC0         to SCL1 input

    RC1PPS     = 0x16;      // Assign SDA1 output to RC1

    SSP1DATPPS = 0x11;      // Assign RC1         to SDA1 input

#endif

    SSP1CON1 = 0b00100110;  // SSPEN enabled, WCOL no collision, SSPOV no overflow,

                            // CKP low hold, SSPM I2C slave 7-bit



    SSP1CON2 = 0b00000000;  // ACKSTAT received, RCEN disabled, RSEN disabled, 

                            // ACKEN disabled, ACKDT acknowledge, SEN disabled, 

                            // GCEN disabled, PEN disabled



    SSP1CON3 = 0b00000000;  // BOEN disabled, AHEN disabled, SBCDE disabled, 

                            // SDAHT 100 ns hold, ACKTIM ackseq, DHEN disabled, 

                            // PCIE disabled, SCIE disabled



    SSP1STAT = 0x00;

    SSP1BUF  = 0x00;

    SSP1MSK  = 0xff;

    SSP1ADD  = I2C_SLAVE_ADDR << 1;

    PIR3bits.SSP1IF = 0;    // Clear the SSP Interrupt flag

    PIE3bits.SSP1IE = 1;    // Enable SSP Interrupts

    INTCONbits.GIE = 1;     // Enable global interrupts

    INTCONbits.PEIE = 1;    // Enable peripheral interrupts

    /*

     * Embedded code never returns from main

     */

    for(;;)

    {



    }

}


The PPS is setup correctly but I do not know if the I2C initialization code is right.







share|improve this answer














share|improve this answer



share|improve this answer








edited Jan 5 at 3:34

























answered Jan 3 at 8:31









Dan1138Dan1138

2717




2717













  • Initialization code added as requested.

    – Zizumara
    Jan 4 at 21:05











  • Thanks. I'll give that PPS configuration a try, but I now I understand that my PPS configuration couldn't have worked because the I2C outputs weren't going anywhere, which would explain why the master wasn't getting an ACK back from the PIC.

    – Zizumara
    Jan 6 at 4:54











  • I just tried those changes to the PPS configuration and my I2C interface is working now. Thanks again.

    – Zizumara
    Jan 6 at 6:52



















  • Initialization code added as requested.

    – Zizumara
    Jan 4 at 21:05











  • Thanks. I'll give that PPS configuration a try, but I now I understand that my PPS configuration couldn't have worked because the I2C outputs weren't going anywhere, which would explain why the master wasn't getting an ACK back from the PIC.

    – Zizumara
    Jan 6 at 4:54











  • I just tried those changes to the PPS configuration and my I2C interface is working now. Thanks again.

    – Zizumara
    Jan 6 at 6:52

















Initialization code added as requested.

– Zizumara
Jan 4 at 21:05





Initialization code added as requested.

– Zizumara
Jan 4 at 21:05













Thanks. I'll give that PPS configuration a try, but I now I understand that my PPS configuration couldn't have worked because the I2C outputs weren't going anywhere, which would explain why the master wasn't getting an ACK back from the PIC.

– Zizumara
Jan 6 at 4:54





Thanks. I'll give that PPS configuration a try, but I now I understand that my PPS configuration couldn't have worked because the I2C outputs weren't going anywhere, which would explain why the master wasn't getting an ACK back from the PIC.

– Zizumara
Jan 6 at 4:54













I just tried those changes to the PPS configuration and my I2C interface is working now. Thanks again.

– Zizumara
Jan 6 at 6:52





I just tried those changes to the PPS configuration and my I2C interface is working now. Thanks again.

– Zizumara
Jan 6 at 6:52




















draft saved

draft discarded




















































Thanks for contributing an answer to Stack Overflow!


  • Please be sure to answer the question. Provide details and share your research!

But avoid …



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f54015997%2ftrying-to-understand-microchip-pic16lf15344-peripheral-pin-selection-for-i2c%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

MongoDB - Not Authorized To Execute Command

Image
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ height:90px;width:728px;box-sizing:border-box; } 0 I have successfully enabled authorization on MongoDB and I have created an account on the admin database and then I created an account for my database called test. The following connection string to connect to my test database works successfully: mongo --host 192.168.17.52 --port 27017 -u user1 -p password --authenticationDatabase test Only problem I have now is, I cannot execute commands such as: show dbs. I get the following error when I try to do so: "errmsg" : "not authorized on admin to execute command { listDatabases: 1.0, lsid: { id: UUID("a1d5bc0d-bc58-485e-b232-270758a89455") }, $db: "admin...
Read more

in spring boot 2.1 many test slices are not allowed anymore due to multiple @BootstrapWith

Image
1 I tried to upgrade a yummy sandwich made of two test slices (@JsonTest and @JdbcTest in my case, crunchy test code in between) adding spring boot 2.1 flavour to it. But it seems it was not much of a success. I cannot annotate my tests with many @...Test since they are now each bringing their own XxxTestContextBootstrapper. It used to work when they all used same SpringBootTestContextBootstrapper. @RunWith(SpringRunner.class) @JdbcTest @JsonTest public class Test { @Test public void test() { System.out.printn("Hello, World !"); } } The error I get from BootstrapUtils is illegalStateException : Configuration error: found multiple declarations of @BootstrapWith for test class I understand I might be doing something wrong here but is there an easy way I could load both Json and Jdbc contex...
Read more

How to fix TextFormField cause rebuild widget in Flutter

Image
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ height:90px;width:728px;box-sizing:border-box; } 0 I've got the same issue at #9280. I tried all solutions from that topic with/without GlobalKey for Scaffold and Form but the problem wasn't fixed. I tried to build a authentication form with login and signup. But the keyboard doesn't show when I tap the TextFormField at the first time. Then I try to input some letter from physical keyboard, the widget is rebuilt. Like this: login screen Nothing to be log when I run flutter run --verbose, so I logged manually. Every tapping on field, the widget called dispose -> init -> build. [√] Flutter (Channel beta, v1.0.0, on Microsoft Windows [Version 10.0.17763.195], ...
Read more