Very hard to read your code, but:
Does your slave support REPEATED START ? Not all slaves do support it.

Cheers,
Manu




On Tue, Oct 16, 2018 at 12:09 AM Neil <picdude3@narwani.org> wrote:
>
> Anyone here used the PIC32 peripheral library for I2C?  I'm having a
> hard time with this, and can't find my ICD3 to help diagnose what's
> happening.
> I'm continuously reading data from a slave I2C device (PIC18F25K42
> based), and the master (PIC32MX320F128H) crashes (reboots) regularly.
> I'm posting about the maser here...
>
> Flags on reboot only have the POR and BOR flags set.  Adding a bit of
> bulk capacitance (10uf) does not help.  And this is happening with both
> Pickit3 power or LiPo w/5V DC-DC power.  I also don't see a way to
> change BOR threshold voltage as with other PIC series.
> Logic analyzer says that it's happening at different points, but always
> between I2C start and stop.
>
> I'm at a loss as to what to test next, but perhaps someone can identify
> something I'm doing wrong?  This is my master code to read data.  The
> delays were put in earlier when testing w/o error-checking, and seems to
> still help to reduce crashes.
> HandleI2CErrors() is just a quick function to check and clear
> arbitration, TX overflow, and RX overflow errors, and also sets an LED
> to alert me, but that LED stays off.
>
> signed int ReadAFEValue(void)
> {
>      signed int result, inVal, retVal;
>
>
>      retVal =3D 1;
>
>      if (PLIB_I2C_BusIsIdle(I2C_ID_1))
>      {
>          PLIB_I2C_MasterStart(I2C_ID_1);
>
>          // Tell AFE to restart result counter and be ready to send data.=
...
> //        delay_us(100);
>          DelayMs(1);
>          if (PLIB_I2C_TransmitterIsReady(I2C_ID_1))
>          {
>
>              PLIB_I2C_TransmitterByteSend(I2C_ID_1,0x54);             //
> Slave addr 0x2A in bits 7:1. 1 in LSB =3D read request, or 0 =3D write re=
q..
>              if (PLIB_I2C_TransmitterByteWasAcknowledged(I2C_ID_1))
>              {
> //                delay_us(100);
>                  DelayMs(1);
>                  if (PLIB_I2C_TransmitterIsReady(I2C_ID_1))
>                  {
>                      PLIB_I2C_TransmitterByteSend(I2C_ID_1,0xB0);
>                  // Command for set mode to read_data mode
>                      if (PLIB_I2C_TransmitterByteWasAcknowledged(I2C_ID_1=
))
>                      {
>                          HandleI2CErrors();
>
>                          // Restart...
> //                        delay_us(200);
>                          DelayMs(1);
>                          if (PLIB_I2C_BusIsIdle(I2C_ID_1))
>                          {
>                              PLIB_I2C_MasterStartRepeat(I2C_ID_1);
>
>                              HandleI2CErrors();
>
>                              // Tell AFE we want to read data now...
> //                            delay_us(200);
>                              DelayMs(1);
>                              if (PLIB_I2C_TransmitterIsReady(I2C_ID_1))
>                              {
> PLIB_I2C_TransmitterByteSend(I2C_ID_1,0x55); // Slave addr 0x2A in bits
> 7:1. 1 in LSB =3D read request, or 0 =3D write req..
>                                  if
> (PLIB_I2C_TransmitterByteWasAcknowledged(I2C_ID_1))
>                                  {
>                                      HandleI2CErrors();
>
> //                                    delay_us(200);
>                                      DelayMs(1);
> PLIB_I2C_MasterReceiverClock1Byte(I2C_ID_1); // Get first byte back from
> AFE.
>
> //                                    delay_us(100);
>                                      DelayMs(1);
>                                      if
> (PLIB_I2C_ReceivedByteIsAvailable(I2C_ID_1))
>                                      {
>                                          if
> (PLIB_I2C_MasterReceiverReadyToAcknowledge(I2C_ID_1))
>                                          {
>                                              result =3D
> PLIB_I2C_ReceivedByteGet(I2C_ID_1);                // TODO -- store this
> somewhere
> PLIB_I2C_ReceivedByteAcknowledge(I2C_ID_1, true);
>                                  //            while
> (!PLIB_I2C_ReceiverByteAcknowledgeHasCompleted(I2C_ID_1));
>                                          }
>                                      }
>
>                                      HandleI2CErrors();
>
> //                                    delay_us(200);
>                                      DelayMs(1);
> PLIB_I2C_MasterReceiverClock1Byte(I2C_ID_1); // Get second byte back
> from AFE.
>
> //                                    delay_us(200);
>                                      DelayMs(1);
>                                      if
> (PLIB_I2C_ReceivedByteIsAvailable(I2C_ID_1))
>                                      {
>                                          if
> (PLIB_I2C_MasterReceiverReadyToAcknowledge(I2C_ID_1))
>                                          {
>                                              inVal =3D
> PLIB_I2C_ReceivedByteGet(I2C_ID_1);                    // TODO -- store
> this somewhere
> PLIB_I2C_ReceivedByteAcknowledge(I2C_ID_1, false);            // NAK
> here is required for last byte
>                                              result  =3D result | (inVal
> << 8);
>                                              retVal =3D result;
>                                          }
>                                      }
>
>                                      HandleI2CErrors();
>
>                                  //    DelayMs(1);
> //                                    delay_us(200);
>                                      DelayMs(1);
>                                      while
> (PLIB_I2C_TransmitterIsReady(I2C_ID_1) =3D=3D 0);                    // T=
ODO
> -- countdown and timeout here?
>                                  }
>                                  else
>                                      retVal =3D -8;
>                              }
>                              else
>                                  retVal =3D -7;
>                          }
>                          else
>                              retVal =3D -6;
>                      }
>                      else
>                          retVal =3D -5;
>                  }
>                  else
>                      retVal =3D -4;
>              }
>              else
>                  retVal =3D -3;
>          }
>          else
>              retVal =3D -2;
>
>          PLIB_I2C_MasterStop(I2C_ID_1);
>      }
>
>      return retVal;
> }        // ReadAFEValue()
>
>
>
> Cheers,
> -Neil
>
>
>
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