Add ADC for temp sensor

Author: hierophect

ports/stm32f4/common-hal/microcontroller/Processor.c

@@ -3,7 +3,6 @@
  *
  * The MIT License (MIT)
  *
- * Copyright (c) 2017 Dan Halbert for Adafruit Industries
  * Copyright (c) 2019 Lucian Copeland for Adafruit Industries
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -34,11 +33,100 @@
 
 #define STM32_UUID ((uint32_t *)0x1FFF7A10)
 
+//Factory calibration locations
+#define ADC_CAL_ADDRESS         (0x1fff7a2a)
+#define ADC_CAL1                ((uint16_t*)(ADC_CAL_ADDRESS + 2))
+#define ADC_CAL2                ((uint16_t*)(ADC_CAL_ADDRESS + 4))
+
+// correction factor for reference value
+STATIC volatile float adc_refcor = 1.0f;
+
+#define CORE_TEMP_V25          (943)  /* (0.76v/3.3v)*(2^ADC resoultion) */
+#define CORE_TEMP_AVG_SLOPE    (3)    /* (2.5mv/3.3v)*(2^ADC resoultion) */
+
 float common_hal_mcu_processor_get_temperature(void) {
-    return NAN;
+    __HAL_RCC_ADC1_CLK_ENABLE();
+
+    //HAL Implementation
+    ADC_HandleTypeDef AdcHandle;
+    ADC_ChannelConfTypeDef sConfig;
+
+    AdcHandle.Instance = ADC1;
+    AdcHandle.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV4;
+    AdcHandle.Init.Resolution = ADC_RESOLUTION_12B;
+    AdcHandle.Init.ScanConvMode = DISABLE;
+    AdcHandle.Init.ContinuousConvMode = DISABLE;
+    AdcHandle.Init.DiscontinuousConvMode = DISABLE;
+    AdcHandle.Init.NbrOfDiscConversion = 0;
+    AdcHandle.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
+    AdcHandle.Init.ExternalTrigConv = ADC_SOFTWARE_START;
+    AdcHandle.Init.DataAlign = ADC_DATAALIGN_RIGHT;
+    AdcHandle.Init.NbrOfConversion = 1;
+    AdcHandle.Init.DMAContinuousRequests = DISABLE;
+    AdcHandle.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
+    HAL_ADC_Init(&AdcHandle);
+
+    ADC->CCR |= ADC_CCR_TSVREFE;
+    ADC->CCR &= ~ADC_CCR_VBATE; // If this somehow got turned on, it'll return bad values. 
+
+    sConfig.Channel = ADC_CHANNEL_TEMPSENSOR; //either 16 or 18, depending on chip
+    sConfig.Rank = 1;
+    sConfig.SamplingTime = ADC_SAMPLETIME_480CYCLES; //Taken from micropython
+    HAL_ADC_ConfigChannel(&AdcHandle, &sConfig);
+
+    HAL_ADC_Start(&AdcHandle);
+    if (HAL_ADC_PollForConversion(&AdcHandle,1) != HAL_OK) {
+        mp_raise_RuntimeError(translate("Temperature read timed out"));
+    }
+    uint32_t value = (uint32_t)HAL_ADC_GetValue(&AdcHandle);
+    HAL_ADC_Stop(&AdcHandle);
+
+    //There's no F4 specific appnote for this but it works the same as the L1 in AN3964
+    float core_temp_avg_slope = (*ADC_CAL2 - *ADC_CAL1) / 80.0;
+    return (((float)value * adc_refcor - *ADC_CAL1) / core_temp_avg_slope) + 30.0f;
+
+    // STATIC uint32_t adc_config_and_read_channel(ADC_HandleTypeDef *adcHandle, uint32_t channel) {
+    // adc_config_channel(adcHandle, channel);
+    // uint32_t raw_value = adc_read_channel(adcHandle);
+
+    // #if defined(STM32F4) || defined(STM32F7)
+    // // ST docs say that (at least on STM32F42x and STM32F43x), VBATE must
+    // // be disabled when TSVREFE is enabled for TEMPSENSOR and VREFINT
+    // // conversions to work.  VBATE is enabled by the above call to read
+    // // the channel, and here we disable VBATE so a subsequent call for
+    // // TEMPSENSOR or VREFINT works correctly.
+    // if (channel == ADC_CHANNEL_VBAT) {
+    //     ADC->CCR &= ~ADC_CCR_VBATE;
+    // }
+    // #endif
+
+    // return raw_value;
+
+    //     int adc_read_core_temp(ADC_HandleTypeDef *adcHandle) {
+    //     int32_t raw_value = adc_config_and_read_ref(adcHandle, ADC_CHANNEL_TEMPSENSOR);
+    //     return ((raw_value - CORE_TEMP_V25) / CORE_TEMP_AVG_SLOPE) + 25;
+    // }
+
+    // #if MICROPY_PY_BUILTINS_FLOAT
+    // // correction factor for reference value
+    // STATIC volatile float adc_refcor = 1.0f;
+
+    // float adc_read_core_temp_float(ADC_HandleTypeDef *adcHandle) {
+    //     int32_t raw_value = adc_config_and_read_ref(adcHandle, ADC_CHANNEL_TEMPSENSOR);
+    //     float core_temp_avg_slope = (*ADC_CAL2 - *ADC_CAL1) / 80.0;
+    //     return (((float)raw_value * adc_refcor - *ADC_CAL1) / core_temp_avg_slope) + 30.0f;
+    // }
 }
 
 float common_hal_mcu_processor_get_voltage(void) {
+//  float adc_read_core_vref(ADC_HandleTypeDef *adcHandle) {
+//     uint32_t raw_value = adc_config_and_read_ref(adcHandle, ADC_CHANNEL_VREFINT);
+
+//     // update the reference correction factor
+//     adc_refcor = ((float)(*VREFIN_CAL)) / ((float)raw_value);
+
+//     return (*VREFIN_CAL) * ADC_SCALE;
+// }
     return NAN;
 }