AD5941 Cant Wake, Wrong ADIID

Hi  andrtnnr ,

We will look into this. I will contact the product owner and get back to you.

Regards,

JC

Thank you!!

Hi,

Is the device entering sleep by AD5940_EnterSleepS() function?

The low power buffers are used in hibernate mode to maintain the charge on the decoupling capacitors to enable faster wakeup from hibernate mode

 Akila 

Yes thats correct. I am using AD5940_EnterSleepS(). Here is my code below, I did change the function names a little but you can see that I am using this routine in the sequencer.

Most of the time, I wait for the FIFO_THRESH interrupt and I can wake up the device to pull the FIFO data and process it. But 3 hours into sampling, this error happens where I cant wake up. And it happens on all 4 of my AD5941 chips within my PCB.

bool AmperometricImplementation::measureSequence(void)
{
   ampLog.trace("CS %d: %s", config.chipSelect, __func__);
   AD5940Err error = AD5940ERR_OK;
   uint32_t const* pSeqCmd;
   uint32_t SeqLen;

   uint32_t WaitClks;
   ClksCalInfo_Type clks_cal;

   clks_cal.DataType        = DATATYPE_SINC2;
   clks_cal.DataCount       = 1;
   clks_cal.ADCSinc2Osr     = ADC_SINC_2OSR;
   clks_cal.ADCSinc3Osr     = ADC_SINC_30SR;
   clks_cal.ADCAvgNum       = 0;
   clks_cal.RatioSys2AdcClk = SYS_CLK_FREQ / ADC_CLK_FREQ;
   afeClksCalculate(&clks_cal, &WaitClks);

   WaitClks += 15;
   afeSEQGenCtrl(bTRUE);
   afeSEQGpioCtrlS(AGPIO_Pin2);
   afeAFECtrlS(AFECTRL_ADCPWR | AFECTRL_SINC2NOTCH, bTRUE);
   afeSEQGenInsert(SEQ_WAIT(16 * 250)); /* wait 250us */
   afeAFECtrlS(AFECTRL_ADCCNV, bTRUE);  /* Start ADC convert*/
   afeSEQGenInsert(SEQ_WAIT(WaitClks)); /* wait for first data ready */
   afeAFECtrlS(AFECTRL_ADCCNV, bFALSE); /* Stop ADC */
   afeSEQGpioCtrlS(0);

   afeWriteReg(REG_ALLON_EI2CON, 0x0009);  // Ensure SPI can wake the device
   afeEnterSleepS();                       /* Goto hibernate by setting SEQTRGSLP */

   /* Sequence end. */
   error = afeSEQGenFetchSeq(&pSeqCmd, &SeqLen);
   afeSEQGenCtrl(bFALSE); /* Stop sequencer generator */

   if (error == AD5940ERR_OK) {
      MeasureSeqInfo.SeqId      = SEQID_0;
      MeasureSeqInfo.SeqRamAddr = InitSeqInfo.SeqRamAddr + InitSeqInfo.SeqLen;
      MeasureSeqInfo.pSeqCmd    = pSeqCmd;
      MeasureSeqInfo.SeqLen     = SeqLen;
      /* Write command to SRAM */
      afeSEQCmdWrite(MeasureSeqInfo.SeqRamAddr, pSeqCmd, SeqLen);
   }
   else {
      ampLog.warn("CS %d: Failed to fetch SEQ Info", config.chipSelect);
      return false;
   }
   return true;
}

And I use the following for the actual interrupt service routine when I go to process the data

Akila  For the time being am I able to have the measurement sequence never hibernate? The wake up timer should theoretically just start up the sequence again regardless of what happening. But what happens when I dont end a sequence with a hibernation and there arent any commands left to execute? Does it just wait?

You can end a sequence without putting it to sleep. The timer (based on Wake up timer configuration) just goes to the next sequence after completing the current sequence.

Akila Can I make it wait without sleeping? Just so that I can still control the sample rate.

Hi,

Could you tell where you are waking up the device from sleep?

 The measure sequence above does configuration, measurement and puts the device to sleep.

Are you doing 

if(AD5940_WakeUp(10) > 10) /* Wakeup AFE by read register, read 10 times at most */
return AD5940ERR_WAKEUP; /* Wakeup Failed */

for waking up?

Yes. 

Inserting waitclks in sequence is done the same way as you have already done in your measure sequence above:

AD5940_SEQGenInsert(SEQ_WAIT(WaitClks));