RTOS application with 3 threads of different priorities: play music, measure temperature (and print results via stdio) and plays with the MMA8451Q sensor and the RGB LEDs

Dependencies:   MMA8451Q mbed-rtos mbed

Revision:
0:d3948113d6d9
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Jan 28 15:26:56 2016 +0000
@@ -0,0 +1,62 @@
+#include "mbed.h"
+#include "rtos.h"
+#include "MMA8451Q.h"
+
+MMA8451Q acc(PTE25,PTE24,0x3A);             //SDA, SCL, I2C address lef shifted
+PwmOut rled(LED_RED);                       //configure RGB LED pins as PWM outputs
+PwmOut gled(LED_GREEN);
+PwmOut bled(LED_BLUE);
+PwmOut buzzer(D3);                          //used to play music
+
+float frequency[]= {659,554,659,554,550,494,554,587,494,659,554,440}; //frequency array
+uint8_t beat[]= {2,2,2,2,2,1,1,2,2,2,2,4};  //beat array
+
+void music(void const *args)
+{
+    while (1) {
+        for (int i=0; i<12; i++) {
+            buzzer.period(1/frequency[i]);  // set PWM period
+            buzzer=0.5;                     // set duty cycle
+            Thread::wait(250*beat[i]);      // hold for beat period
+        }
+    }
+}
+
+void thermometer(void const *args)
+{
+    AnalogIn ain(A0);                       // Analog input at PTB0
+    uint32_t mysum;                         // Used for summation
+
+    printf("\r\nTask3: analog thermometer - with averaging\r\n");
+    while(1) {
+        mysum = 0;
+        for(int i=0; i<3300; i++) {
+            mysum += ain.read_u16();        // sum up raw 16-bit data
+        }
+        float voltage = mysum>>16;          // voltage in millivolts
+        float tempC = (voltage -500)/10;    // tempereature in Celsius
+        printf("voltage: %5.0f mV temp: %5.1f C\r\n",voltage,tempC);
+        Thread::wait(2000);
+    }
+}
+
+
+int main(void)
+{
+    Thread thread2(music);                  //Define a new task
+    thread2.set_priority(osPriorityHigh);   //Give it high priority
+
+    Thread thread3(thermometer);            //Define another new task
+    thread3.set_priority(osPriorityLow);    //Give it high priority
+
+    while (true) {                          //Run the default task
+        float x, y, z;
+        x = abs(acc.getAccX());             //Read X component of acceleration
+        y = abs(acc.getAccY());             //Read Y component of acceleration
+        z = abs(acc.getAccZ());             //Read Z component of acceleration
+        rled = 1.0f - x;                    //Negative logic is used as the LEDs
+        gled = 1.0f - y;                    //are of common anode type...
+        bled = 1.0f - z;
+        Thread::wait(100);                  //Time period is ~ 100 ms
+    }
+}
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