main.cpp

00001 #include "mbed.h"
00002 #include "rtos.h"
00003 AnalogIn adc(A4);
00004 DigitalOut led1(LED1);
00005 
00006 typedef uint32_t message_t;
00007 Queue <message_t, 4> queue;
00008 
00009 void led1_thread(void const *args)
00010 {
00011     while (true) {
00012         led1 = !led1;
00013         Thread::wait(1000);
00014     }
00015 }
00016 
00017 //--- ADC Interrupt handler -----------------
00018 extern "C" void ADC1_IRQHandler()
00019 {
00020     NVIC_ClearPendingIRQ(ADC_IRQn);             //Clear ADC Interrupt Request Flag
00021     uint16_t raw = ADC1->DR;
00022     queue.put((message_t*)raw);                 //Send result through a Queue
00023 }
00024 
00025 //--- Start conversion, wait for result -----
00026 uint16_t adc_read(uint32_t ch)
00027 {
00028     ADC1->SQR3 = ch;                              //set conversion channel
00029     ADC1->SMPR2 = 7;                              //Sample time =480
00030     ADC1->CR1 |= ADC_CR1_EOCIE;                   //enable interrupt
00031     ADC1->CR2 |= ADC_CR2_SWSTART;                 //Start conversion
00032     osEvent evt = queue.get();                    //Wait for a message
00033     return (uint16_t)evt.value.v;                 //Return obtained value
00034 }
00035 
00036 int main()
00037 {
00038     int32_t v25 = 760;                            //Voltage at 25C (in millivolts)
00039     float m = 2.5;                                //Slope  mV per degree)
00040     uint16_t dummy = adc.read();                  //needed for ADC configuration
00041     ADC123_COMMON->CCR |= ADC_CCR_TSVREFE;        //Enable inner channels
00042     NVIC_SetVector(ADC_IRQn,(uint32_t)&ADC1_IRQHandler); //Attach ADC ISR
00043     NVIC_EnableIRQ(ADC_IRQn);                     //Enable ADC interrupts
00044     Thread thread1(led1_thread);
00045     printf("\r\n Lab09 ADC interrupt in RTOS environment\r\n");
00046     while(true) {
00047         uint32_t a1 = 0;
00048         uint32_t a2 = 0;
00049         for(int i=0; i<3300; i++) {
00050             a1 += adc_read(11);                    //Measure voltage at A4 (PTC_1)
00051             a2 += adc_read(18);                    //Internal temperature sensor
00052         }
00053         float v1 = a1/4096.0f;                     //Convert v1 to millivolts
00054         float temp1 = (v1-500)/10.0;               //MCP9700 temperature in Celsius
00055         float v2 = a2/4096.0f;                     //Convert v2 to millivolts
00056         float temp2 = 25.0f+(v2-v25)/m;            //Calculate temp in Celsius
00057         printf("A4 = %.0f mV  Temp = %.1f C  Inner Ts: %.0f mV  Temp = %.1f C\r\n",v1,temp1,v2,temp2);
00058         Thread::wait(2000);
00059     }
00060 
00061 }