STM32F4 ADC internal channels update

Author: jeromecoutant

targets/TARGET_STM/TARGET_STM32F4/analogin_device.c

@@ -161,16 +161,15 @@ uint16_t adc_read(analogin_t *obj)
             break;
         case 16:
             sConfig.Channel = ADC_CHANNEL_TEMPSENSOR;
+            sConfig.SamplingTime = ADC_SAMPLETIME_480CYCLES; // Minimum ADC sampling time when reading the temperature is 10us
             break;
         case 17:
             sConfig.Channel = ADC_CHANNEL_VREFINT;
-            /*  From experiment, measurement needs max sampling time to be valid */
-            sConfig.SamplingTime = ADC_SAMPLETIME_480CYCLES;
+            sConfig.SamplingTime = ADC_SAMPLETIME_480CYCLES; // Minimum ADC sampling time when reading the internal reference voltage is 10us
             break;
         case 18:
             sConfig.Channel = ADC_CHANNEL_VBAT;
-            /*  From experiment, measurement needs max sampling time to be valid */
-            sConfig.SamplingTime = ADC_SAMPLETIME_480CYCLES;
+            sConfig.SamplingTime = ADC_SAMPLETIME_480CYCLES; // Minimum ADC sampling time when reading the VBAT is 5us
             break;
         default:
             return 0;

targets/TARGET_STM/TARGET_STM32F4/device/stm32f4xx_hal_adc.h

@@ -44,6 +44,9 @@
 /* Includes ------------------------------------------------------------------*/
 #include "stm32f4xx_hal_def.h"
 
+/* Include low level driver */
+#include "stm32f4xx_ll_adc.h"
+
 /** @addtogroup STM32F4xx_HAL_Driver
   * @{
   */

targets/TARGET_STM/TARGET_STM32F4/device/stm32f4xx_ll_adc.h

@@ -269,6 +269,18 @@ extern "C" {
 /* ADC registers bits positions */
 #define ADC_CR1_RES_BITOFFSET_POS          (24U) /* Value equivalent to POSITION_VAL(ADC_CR1_RES) */
 #define ADC_TR_HT_BITOFFSET_POS            (16U) /* Value equivalent to POSITION_VAL(ADC_TR_HT) */
+
+/* ADC internal channels related definitions */
+/* Internal voltage reference VrefInt */
+#define VREFINT_CAL_ADDR                   ((uint16_t*) (0x1FFF7A2AU)) /* Internal voltage reference, address of parameter VREFINT_CAL: VrefInt ADC raw data acquired at temperature 30 DegC (tolerance: +-5 DegC), Vref+ = 3.3 V (tolerance: +-10 mV). */
+#define VREFINT_CAL_VREF                   ( 3300U)                    /* Analog voltage reference (Vref+) value with which temperature sensor has been calibrated in production (tolerance: +-10 mV) (unit: mV). */
+/* Temperature sensor */
+#define TEMPSENSOR_CAL1_ADDR               ((uint16_t*) (0x1FFF7A2CU)) /* Internal temperature sensor, address of parameter TS_CAL1: On STM32F4, temperature sensor ADC raw data acquired at temperature  30 DegC (tolerance: +-5 DegC), Vref+ = 3.3 V (tolerance: +-10 mV). */
+#define TEMPSENSOR_CAL2_ADDR               ((uint16_t*) (0x1FFF7A2EU)) /* Internal temperature sensor, address of parameter TS_CAL2: On STM32F4, temperature sensor ADC raw data acquired at temperature 110 DegC (tolerance: +-5 DegC), Vref+ = 3.3 V (tolerance: +-10 mV). */
+#define TEMPSENSOR_CAL1_TEMP               (( int32_t)   30)           /* Internal temperature sensor, temperature at which temperature sensor has been calibrated in production for data into TEMPSENSOR_CAL1_ADDR (tolerance: +-5 DegC) (unit: DegC). */
+#define TEMPSENSOR_CAL2_TEMP               (( int32_t)  110)           /* Internal temperature sensor, temperature at which temperature sensor has been calibrated in production for data into TEMPSENSOR_CAL2_ADDR (tolerance: +-5 DegC) (unit: DegC). */
+#define TEMPSENSOR_CAL_VREFANALOG          ( 3300U)                    /* Analog voltage reference (Vref+) voltage with which temperature sensor has been calibrated in production (+-10 mV) (unit: mV). */
+
 /**
   * @}
   */
@@ -1654,6 +1666,64 @@ typedef struct
    / __LL_ADC_DIGITAL_SCALE(__ADC_RESOLUTION__)                                \
   )
 
+/**
+  * @brief  Helper macro to calculate the temperature (unit: degree Celsius)
+  *         from ADC conversion data of internal temperature sensor.
+  * @note   Computation is using temperature sensor calibration values
+  *         stored in system memory for each device during production.
+  * @note   Calculation formula:
+  *           Temperature = ((TS_ADC_DATA - TS_CAL1)
+  *                           * (TS_CAL2_TEMP - TS_CAL1_TEMP))
+  *                         / (TS_CAL2 - TS_CAL1) + TS_CAL1_TEMP
+  *           with TS_ADC_DATA = temperature sensor raw data measured by ADC
+  *                Avg_Slope = (TS_CAL2 - TS_CAL1)
+  *                            / (TS_CAL2_TEMP - TS_CAL1_TEMP)
+  *                TS_CAL1   = equivalent TS_ADC_DATA at temperature
+  *                            TEMP_DEGC_CAL1 (calibrated in factory)
+  *                TS_CAL2   = equivalent TS_ADC_DATA at temperature
+  *                            TEMP_DEGC_CAL2 (calibrated in factory)
+  *         Caution: Calculation relevancy under reserve that calibration
+  *                  parameters are correct (address and data).
+  *                  To calculate temperature using temperature sensor
+  *                  datasheet typical values (generic values less, therefore
+  *                  less accurate than calibrated values),
+  *                  use helper macro @ref __LL_ADC_CALC_TEMPERATURE_TYP_PARAMS().
+  * @note   As calculation input, the analog reference voltage (Vref+) must be
+  *         defined as it impacts the ADC LSB equivalent voltage.
+  * @note   Analog reference voltage (Vref+) must be either known from
+  *         user board environment or can be calculated using ADC measurement
+  *         and ADC helper macro @ref __LL_ADC_CALC_VREFANALOG_VOLTAGE().
+  * @note   On this STM32 serie, calibration data of temperature sensor
+  *         corresponds to a resolution of 12 bits,
+  *         this is the recommended ADC resolution to convert voltage of
+  *         temperature sensor.
+  *         Otherwise, this macro performs the processing to scale
+  *         ADC conversion data to 12 bits.
+  * @param  __VREFANALOG_VOLTAGE__  Analog reference voltage (unit: mV)
+  * @param  __TEMPSENSOR_ADC_DATA__ ADC conversion data of internal
+  *                                 temperature sensor (unit: digital value).
+  * @param  __ADC_RESOLUTION__      ADC resolution at which internal temperature
+  *                                 sensor voltage has been measured.
+  *         This parameter can be one of the following values:
+  *         @arg @ref LL_ADC_RESOLUTION_12B
+  *         @arg @ref LL_ADC_RESOLUTION_10B
+  *         @arg @ref LL_ADC_RESOLUTION_8B
+  *         @arg @ref LL_ADC_RESOLUTION_6B
+  * @retval Temperature (unit: degree Celsius)
+  */
+#define __LL_ADC_CALC_TEMPERATURE(__VREFANALOG_VOLTAGE__,\
+                                  __TEMPSENSOR_ADC_DATA__,\
+                                  __ADC_RESOLUTION__)                              \
+  (((( ((int32_t)((__LL_ADC_CONVERT_DATA_RESOLUTION((__TEMPSENSOR_ADC_DATA__),     \
+                                                    (__ADC_RESOLUTION__),          \
+                                                    LL_ADC_RESOLUTION_12B)         \
+                   * (__VREFANALOG_VOLTAGE__))                                     \
+                  / TEMPSENSOR_CAL_VREFANALOG)                                     \
+        - (int32_t) *TEMPSENSOR_CAL1_ADDR)                                         \
+     ) * (int32_t)(TEMPSENSOR_CAL2_TEMP - TEMPSENSOR_CAL1_TEMP)                    \
+    ) / (int32_t)((int32_t)*TEMPSENSOR_CAL2_ADDR - (int32_t)*TEMPSENSOR_CAL1_ADDR) \
+   ) + TEMPSENSOR_CAL1_TEMP                                                        \
+  )
 
 /**
   * @brief  Helper macro to calculate the temperature (unit: degree Celsius)