Question
Using ADCCTRL to read an external voltage
Starting with the BLE_Heartrate example, I want to measure a voltage on PA8 of STM32WBA65. The BLE_Heartrate project already has the option of using ADCCTRL to read the internal temperature so as to calibrate the BLE power.
I have added PA8 as ADC_Channel1 in CubeMX. Do I need to call MX_ADC4_Init or not?
How do I achieve a read of PA8 in my timed task? The call to ADCCTRL_RequestRawValue always returns without error, but the value read is always 1 or 2. There is definitely 1.0v on this pin.
My code (copied from the temp_measurement.c of WPAN) is:
static ADCCTRL_Handle_t LLADCRequest_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_0,//LL_ADC_CHANNEL_TEMPSENSOR,
.Rank = LL_ADC_REG_RANK_2,
.SamplingTime = LL_ADC_SAMPLINGTIME_COMMON_1
}
};
uint16_t battery = 3700;
ADCCTRL_Cmd_Status_t eReturn = ADCCTRL_RegisterHandle (&LLADCRequest_Handle);
UTIL_SEQ_PauseTask(1U << CFG_TASK_TEMP_MEAS);
/* 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);
/* Request ADC IP activation */
ADCCTRL_Cmd_Status_t ret = ADCCTRL_RequestIpState(&LLADCRequest_Handle, ADC_ON);
/* Get temperature from ADC dedicated channel */
// ADCCTRL_RequestTemperature (&LLADCRequest_Handle,
// &temperature_value);
ret = ADCCTRL_RequestRawValue (&LLADCRequest_Handle, &battery);
/* Request ADC IP deactivation */
ret = ADCCTRL_RequestIpState(&LLADCRequest_Handle, ADC_OFF);
/* Exit limited critical section */
UTILS_EXIT_LIMITED_CRITICAL_SECTION();
// Resume BLE temp task
UTIL_SEQ_ResumeTask(1U << CFG_TASK_TEMP_MEAS);