InternalTemperature.cpp

00001 #include "InternalTemperature.h"
00002 
00003 void temp_init(analogin_t *obj) {
00004     obj->adc = (ADCName)16;
00005 
00006     // Enable ADC1 clock source.
00007     RCC->APB2ENR |= RCC_APB2ENR_ADC1EN;
00008 
00009     // Enable the ADC
00010     ADC1->CR2 |= ADC_CR2_ADON;
00011     
00012     // Enable internal temperature sensor.
00013     ADC->CCR |= ADC_CCR_TSVREFE;
00014     
00015     // Set longest sample time just to be safe.
00016     ADC1->SMPR1 |= 0x1c;
00017 }
00018 
00019 static inline uint32_t temp_read(analogin_t *obj) {
00020     // Select the appropriate channel
00021     ADC1->SQR3 = (int) obj->adc;
00022 
00023     // Start conversion
00024     ADC1->CR2 |= ADC_CR2_SWSTART;
00025 
00026     // Wait for conversion to finish
00027     while (!(ADC1->SR & ADC_SR_EOC));
00028 
00029     uint32_t data = ADC1->DR;
00030     return data; // 12 bit
00031 }
00032 
00033 static inline uint32_t temp_read_u32(analogin_t *obj) {
00034     uint32_t value;
00035     value = temp_read(obj);
00036     return value;
00037 }
00038 
00039 uint16_t temperature_read_u16(analogin_t *obj) {
00040     uint32_t value = temp_read_u32(obj);
00041 
00042     return (value << 4) | ((value >> 8) & 0x000F); // 12 bit
00043 }
00044 
00045 float temperature_read(analogin_t *obj) {
00046     uint32_t value = temp_read_u32(obj);
00047     float ret = value * (1.0f / (float)0xFFF) * 3.0f;
00048     ret = (ret - 0.76f) / 2.5f + 25.0f;
00049 
00050     return ret;
00051 }