Reading ADC4 on WBA25CE1

[suiunbek]

Hi,

I modified the BLE_HeartRate example for Nucleo-WBA25CE1 by adding another channel - IN8 - to read the voltage of a solar panel. The input is between 0V and 3V because i use the divider. In CubeMX I added an additional channel IN8 and generated the code. In the code I define the handle for ADCCTRL:

ADCCTRL_Handle_t LLVoltageRequest_Handle =
{
  .Uid = 0x00,
  .State = ADCCTRL_HANDLE_NOT_REG,
  .InitConf =
  {
    .ConvParams =
    {
      .TriggerFrequencyMode = LL_ADC_TRIGGER_FREQ_LOW,
      .Resolution = LL_ADC_RESOLUTION_12B,
      .DataAlign = LL_ADC_DATA_ALIGN_RIGHT,
      .TriggerStart = LL_ADC_REG_TRIG_SOFTWARE,
      .TriggerEdge = LL_ADC_REG_TRIG_EXT_RISING,
      .ConversionMode = LL_ADC_REG_CONV_SINGLE,
      .DmaTransfer = LL_ADC_REG_DMA_TRANSFER_NONE,
      .Overrun = LL_ADC_REG_OVR_DATA_OVERWRITTEN,
      .SamplingTimeCommon1 = LL_ADC_SAMPLINGTIME_814CYCLES_5,
      .SamplingTimeCommon2 = LL_ADC_SAMPLINGTIME_1CYCLE_5
    },
    .SeqParams =
    {
      .Setup = LL_ADC_REG_SEQ_CONFIGURABLE,
      .Length = LL_ADC_REG_SEQ_SCAN_DISABLE,
      .DiscMode = LL_ADC_REG_SEQ_DISCONT_DISABLE
    },
    .LowPowerParams =
    {
      .AutoPowerOff = DISABLE,
      .AutonomousDPD = LL_ADC_LP_AUTONOMOUS_DPD_DISABLE
    }
  },
  .ChannelConf =
  {
    .Channel = LL_ADC_CHANNEL_8,
    .Rank = LL_ADC_REG_RANK_1,
    .SamplingTime = LL_ADC_SAMPLINGTIME_COMMON_1
  }
};

I register the handle and read the ADC4 in the task triggered by the WakeUp timer.

void Task_AdcSample(void)
{
    LOG_INFO_APP("\r\nADC Sample\r\n");

    uint16_t raw = 0;
    ADCCTRL_Cmd_Status_t ret;

    /* Enter limited critical section : disable all the interrupts with priority higher than RCC one
     * Concerns link layer interrupts (high and SW low) or any other high priority user system interrupt
     */
    UTILS_ENTER_LIMITED_CRITICAL_SECTION(RCC_INTR_PRIO<<4);

    /* Turn ADC on */
    ret = ADCCTRL_RequestIpState(&LLVoltageRequest_Handle, ADC_ON);
    if (ret != ADCCTRL_OK)
    {
        LOG_INFO_APP("ADC ON failed: %d\r\n", ret);
        return;
    }

    /* Read raw value */
    ret = ADCCTRL_RequestRawValue(&LLVoltageRequest_Handle, &raw);
    if (ret != ADCCTRL_OK)
    {
        LOG_INFO_APP("ADC read failed: %d\r\n", ret);
    }
    else
    {
        LOG_INFO_APP("ADC4 raw = %u\r\n", raw);
    }

    /* Turn ADC off — release back to BLE stack */
    ADCCTRL_RequestIpState(&LLVoltageRequest_Handle, ADC_OFF);

    /* Exit limited critical section */
    UTILS_EXIT_LIMITED_CRITICAL_SECTION();

    LOG_INFO_APP("ADC4 raw = %u\r\n", raw);
    uint32_t voltage_mv = (uint32_t)(raw * 3300 * 2) / 4095;
    LOG_INFO_APP("ADC4 raw=%u voltage=%lu.%03lu V\r\n",
                 raw,
                 voltage_mv / 1000,
                 voltage_mv % 1000);
}

I keep getting the same value irrespective if i connect the solar panel or if i connect PA1 to GND:

ADC4 raw=301 voltage=0.485 V

I can read the temperature channel and get values around 960.

I wonder if it is possible to concurrently read external channel and have the internal temperature channel for BLE Stack.