main.cpp

00001 #include "mbed.h"
00002 #include "rtos.h"
00003 
00004 //------------------------------------
00005 // Serial configuration (Put on hyperterminal or Putty)
00006 // 115200 bauds, 8-bit data, no parity
00007 //------------------------------------
00008 
00009 Serial serialIO(SERIAL_TX, SERIAL_RX);
00010 
00011 DigitalOut led2(LED2);
00012 DigitalIn button(USER_BUTTON);
00013 
00014 // Some data queue
00015 typedef struct {
00016     float    voltage;   /* AD result of measured voltage */
00017     uint32_t counter;   /* A counter value               */
00018 } message_t;
00019 
00020 MemoryPool<message_t, 16> mpool;
00021 Queue<message_t, 16> queue;
00022 
00023 // Mutex shared by threads that want's to use the serial port
00024 Mutex stdio_mutex;
00025 
00026 void toogleLed(void const *args)
00027 {
00028     // Toogle led
00029     led2 = !led2;
00030 }
00031 
00032 void check_button(void const *args)
00033 {
00034     while (true) {
00035         // Read button
00036         int butVal = button;
00037 
00038         // To avoid using the serial port at the same time by two threads use the mutex
00039         stdio_mutex.lock();
00040         serialIO.printf("Button state is:%d\r\n",butVal);
00041         stdio_mutex.unlock();
00042 
00043         // Put thread in wait state for 100ms
00044         Thread::wait(300);
00045     }
00046 }
00047 
00048 void data_producer(void const *args)
00049 {
00050     uint32_t i = 0;
00051     while (true) {
00052         i++; // fake data update
00053         message_t *message = mpool.alloc();
00054         message->voltage = (i * 0.1) * 33;
00055         message->counter = i;
00056         queue.put(message);
00057         Thread::wait(2000);
00058     }
00059 }
00060 
00061 void data_consumer(void const *args)
00062 {
00063     while(true) {
00064         // Block until there is an event on the queue
00065         osEvent evt = queue.get();
00066         if (evt.status == osEventMessage) {
00067             message_t *message = (message_t*)evt.value.p;
00068 
00069             // Grab mutex to print data
00070             stdio_mutex.lock();
00071             serialIO.printf("\nVoltage: %.2f V\n\r"   , message->voltage);
00072             serialIO.printf("Number of cycles: %u\n\r", message->counter);
00073             stdio_mutex.unlock();
00074 
00075             mpool.free(message);
00076         }
00077     }
00078 }
00079 
00080 int main()
00081 {
00082     // Configure the serial speed.
00083     serialIO.baud(115200);
00084     serialIO.printf("Learning Microcontrollers with mbed !\r\n");
00085 
00086     // Start a thread to togle the led    
00087     Thread thread_2(check_button);
00088     Thread thread_3(data_producer);
00089     Thread thread_4(data_consumer);
00090     
00091     // Periodically call a function
00092     RtosTimer timerTogLed(toogleLed, osTimerPeriodic);
00093     timerTogLed.start(1000);
00094 
00095     // Lock forever here...
00096     Thread::wait(osWaitForever);
00097 }