temperature_sensor.c

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00001 /**@file temperature_sensor.c
00002  * @brief MB851 temperature sensor APIS 
00003  *
00004  *
00005  * <!--(C) COPYRIGHT 2010 STMicroelectronics. All rights reserved.        -->
00006  */
00007 #include PLATFORM_HEADER
00008 #include BOARD_HEADER
00009 #include "hal/hal.h"
00010 #include "hal/error.h"
00011 #include "hal/micro/temperature_sensor.h"
00012 #include "hal/micro/adc.h"
00013 
00014 void temperatureSensor_Init(void)
00015 {
00016    /* Configure temperature sensor GPIO */
00017    halGpioConfig(TEMPERATURE_SENSOR_GPIO,GPIOCFG_ANALOG);
00018    /* Init ADC driver */
00019    halInternalInitAdc();
00020   
00021    /*
00022     NOTE: 
00023     The ADC extended range is inaccurate due to the high voltage mode bug of the general purpose ADC 
00024     (see STM32W108 errata). As consequence, it is not reccomended to use this ADC driver for getting
00025     the temperature values. 
00026     */
00027 #ifdef ENABLE_ADC_EXTENDED_RANGE_BROKEN
00028     halAdcSetRange(TRUE);
00029 #endif /* ENABLE_ADC_EXTENDED_RANGE_BROKEN */
00030 }/* end temperatureSensor_Init() */
00031 
00032 int32u temperatureSensor_GetValue(void)
00033 {
00034    static int16u ADCvalue;
00035    static int16s volts;
00036 
00037     /*
00038      NOTE: 
00039      The ADC extended range is inaccurate due to the high voltage mode bug of the general purpose ADC 
00040      (see STM32W108 errata). As consequence, it is not reccomended to use this ADC driver for getting
00041      the temperature values. 
00042     */
00043     halStartAdcConversion(ADC_USER_APP, ADC_REF_INT, ADC_SOURCE_ADC2_VREF2, ADC_CONVERSION_TIME_US_4096);
00044   
00045     halReadAdcBlocking(ADC_USER_APP, &ADCvalue); // This blocks for a while, about 4ms.
00046   
00047     // 100 uVolts
00048     volts = halConvertValueToVolts(ADCvalue);
00049   
00050     return ((18641 - (int32s)volts)*100)/1171;  
00051 }/* end temperatureSensor_GetValue() */
00052