Using ADC interrupts in RTOS environment. This program also demonstrates the usage of RTOS API function calls from interrupt.

Dependencies:   mbed mbed-rtos

Files at this revision

API Documentation at this revision

Comitter:
cspista
Date:
Sun Apr 10 12:20:27 2022 +0000
Commit message:
Final version

Changed in this revision

main.cpp Show annotated file Show diff for this revision Revisions of this file
mbed-rtos.lib Show annotated file Show diff for this revision Revisions of this file
mbed.bld Show annotated file Show diff for this revision Revisions of this file
diff -r 000000000000 -r b6055a7af0c9 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sun Apr 10 12:20:27 2022 +0000
@@ -0,0 +1,61 @@
+#include "mbed.h"
+#include "rtos.h"
+AnalogIn adc(A4);
+DigitalOut led1(LED1);
+
+typedef uint32_t message_t;
+Queue <message_t, 4> queue;
+
+void led1_thread(void const *args)
+{
+    while (true) {
+        led1 = !led1;
+        Thread::wait(1000);
+    }
+}
+
+//--- ADC Interrupt handler -----------------
+extern "C" void ADC1_IRQHandler()
+{
+    NVIC_ClearPendingIRQ(ADC_IRQn);             //Clear ADC Interrupt Request Flag
+    uint16_t raw = ADC1->DR;
+    queue.put((message_t*)raw);                 //Send result through a Queue
+}
+
+//--- Start conversion, wait for result -----
+uint16_t adc_read(uint32_t ch)
+{
+    ADC1->SQR3 = ch;                              //set conversion channel
+    ADC1->SMPR2 = 7;                              //Sample time =480
+    ADC1->CR1 |= ADC_CR1_EOCIE;                   //enable interrupt
+    ADC1->CR2 |= ADC_CR2_SWSTART;                 //Start conversion
+    osEvent evt = queue.get();                    //Wait for a message
+    return (uint16_t)evt.value.v;                 //Return obtained value
+}
+
+int main()
+{
+    int32_t v25 = 760;                            //Voltage at 25C (in millivolts)
+    float m = 2.5;                                //Slope  mV per degree)
+    uint16_t dummy = adc.read();                  //needed for ADC configuration
+    ADC123_COMMON->CCR |= ADC_CCR_TSVREFE;        //Enable inner channels
+    NVIC_SetVector(ADC_IRQn,(uint32_t)&ADC1_IRQHandler); //Attach ADC ISR
+    NVIC_EnableIRQ(ADC_IRQn);                     //Enable ADC interrupts
+    Thread thread1(led1_thread);
+    printf("\r\n Lab09 ADC interrupt in RTOS environment\r\n");
+    while(true) {
+        uint32_t a1 = 0;
+        uint32_t a2 = 0;
+        for(int i=0; i<3300; i++) {
+            a1 += adc_read(11);                    //Measure voltage at A4 (PTC_1)
+            a2 += adc_read(18);                    //Internal temperature sensor
+        }
+        float v1 = a1/4096.0f;                     //Convert v1 to millivolts
+        float temp1 = (v1-500)/10.0;               //MCP9700 temperature in Celsius
+        float v2 = a2/4096.0f;                     //Convert v2 to millivolts
+        float temp2 = 25.0f+(v2-v25)/m;            //Calculate temp in Celsius
+        printf("A4 = %.0f mV  Temp = %.1f C  Inner Ts: %.0f mV  Temp = %.1f C\r\n",v1,temp1,v2,temp2);
+        Thread::wait(2000);
+    }
+
+}
diff -r 000000000000 -r b6055a7af0c9 mbed-rtos.lib
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-rtos.lib	Sun Apr 10 12:20:27 2022 +0000
@@ -0,0 +1,1 @@
+https://os.mbed.com/users/mbed_official/code/mbed-rtos/#5713cbbdb706
diff -r 000000000000 -r b6055a7af0c9 mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Sun Apr 10 12:20:27 2022 +0000
@@ -0,0 +1,1 @@
+https://os.mbed.com/users/mbed_official/code/mbed/builds/65be27845400
\ No newline at end of file