I want to use a timer to sample a signal with the ADC at a regular interval. Seems like the ADC just runs over and over on the first timer trigger and doesn't respect the timing after that.

[BStic.2]

So, I have TIM2 setup to trigger an ADC conversion and the DMA moves the samples out to RAM. I want to do this every 100us for 1000 iterations. Sounds pretty straight forward. There are 3 ADC channels being sampled using the sequencer on every trigger, so 3000 samples total. Everything works except for the timing. I turned on the timer interrupt and I am only getting to around 600 interrupts when the DMA reports that all the samples have been transferred. I expect there to be 1000 timer ticks. It seems like the ADC is not getting triggered on the timer interrupt, but on something else. Ive tried a lot of configurations and it never seems to change the outcome. Im stumped... Micro is the STM32WB55

Timer setup:

SENS_Tim2.Instance = TIM2;
  SENS_Tim2.Init.Prescaler = ((SystemCoreClock / 1000000u) - 1u); // Scale input clock to 1mhz
  SENS_Tim2.Init.CounterMode = TIM_COUNTERMODE_UP;
  SENS_Tim2.Init.Period = ((1000000u / SENS_PUMP_SAMPLE_FREQ) - 1u);
  SENS_Tim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  SENS_Tim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  LOG_ASSERT_RETVAL(HAL_TIM_Base_Init(&SENS_Tim2));
 
  clkCfg.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
  LOG_ASSERT_RETVAL(HAL_TIM_ConfigClockSource(&SENS_Tim2, &clkCfg));
 
  mCfg.MasterOutputTrigger = TIM_TRGO_UPDATE;
  mCfg.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  LOG_ASSERT_RETVAL(HAL_TIMEx_MasterConfigSynchronization(&SENS_Tim2, &mCfg));
 
  LOG_ASSERT_RETVAL(HAL_TIM_Base_Start_IT(&SENS_Tim2));

ADC setup:

(void)memset(&SENS_Adc, 0 , sizeof(SENS_Adc));
 
  // Count the number of channels to convert
  convCount = SENS_countChannels();
 
  // Need at least 1.
  LOG_ASSERT(convCount > 0);
 
  // Clock config: SYSCLK -> HCLK1 -> APB2 PCLK2 -> ADC CLK
  //               SYSCLK = HSE, 32 MHz
  //               APB PCLK2 = HSE / 1
  //               ADC CLK = PCLK / 2 = 16 MHz
  SENS_Adc.Instance = ADC1;
  SENS_Adc.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV2;
  SENS_Adc.Init.Resolution = ADC_RESOLUTION_12B;
  SENS_Adc.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  SENS_Adc.Init.ScanConvMode = ADC_SCAN_ENABLE;
  SENS_Adc.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
  SENS_Adc.Init.LowPowerAutoWait = DISABLE;
  SENS_Adc.Init.ContinuousConvMode = DISABLE;
  SENS_Adc.Init.NbrOfConversion = convCount;
  SENS_Adc.Init.ExternalTrigConv = ADC_EXTERNALTRIG_T2_TRGO;
  SENS_Adc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_FALLING;
  SENS_Adc.Init.DMAContinuousRequests = DISABLE;
  SENS_Adc.Init.Overrun = ADC_OVR_DATA_OVERWRITTEN;
  SENS_Adc.Init.OversamplingMode = ENABLE;
  SENS_Adc.Init.Oversampling.Ratio = ADC_OVERSAMPLING_RATIO_4;
  SENS_Adc.Init.Oversampling.RightBitShift = ADC_RIGHTBITSHIFT_2;
  SENS_Adc.Init.Oversampling.TriggeredMode = ADC_TRIGGEREDMODE_SINGLE_TRIGGER;
  SENS_Adc.Init.Oversampling.OversamplingStopReset = ADC_REGOVERSAMPLING_CONTINUED_MODE;
  // Init the ADC
  LOG_ASSERT_RETVAL(HAL_ADC_Init(&SENS_Adc));
 
  // Setup common config
  cfg.SamplingTime = ADC_SAMPLETIME_24CYCLES_5;
  cfg.SingleDiff = ADC_SINGLE_ENDED;
  cfg.OffsetNumber = ADC_OFFSET_NONE;
 
  // Set SMPS to Bypass mode
  HAL_PWREx_SMPS_SetMode(PWR_SMPS_BYPASS);
 
  // Setup the ADC DMA
  DMAMGR_SessionStart(DMAMGR_ADC);
 
  // Configure each channel
  for(i = 0; i < convCount; ++i)
  {
    cfg.Channel = SENS_AdcChannel[SENS_AdcMeasurementChannels[i]];
    cfg.Rank = SENS_IndexToRank[i];
    // configure the channel
    LOG_ASSERT_RETVAL(HAL_ADC_ConfigChannel(&SENS_Adc, &cfg));
  }

[BStic.2 · Accepted solution]

Never mind, I would delete this post if I could, but I cant... Issue was the interrupt frequency was too high for the load...

[Otavio Borges]

Mark as answered