This demo uses the mbed RTOS to run eight threads (including main). The threads are using different I/O devices on the application board. Several of the threads output to the LCD and an OS mutex lock is used to control access to the LCD and make the LCD thread safe.

Dependencies:   C12832_lcd LCD_fonts mbed-rtos mbed

Fork of lab1 by Peter Drescher

main.cpp

Committer:
dreschpe
Date:
2012-10-16
Revision:
1:1c6a9eaf55b5
Parent:
0:f6a57b843f79
Child:
2:a69c8c5f5b03

File content as of revision 1:1c6a9eaf55b5:

// example to test the mbed Lab Board lcd
// Pot1 change the contrast
// Pot2 change the speed of the sin wave


#include "mbed.h"
#include "rtos.h"
#include "Small_6.h"
#include "Small_7.h"
#include "Arial_9.h"
#include "stdio.h"
#include "C12832_lcd.h"

Serial pc(USBTX, USBRX);


// LCD object
C12832_LCD LCD("LCD");

AnalogIn Pot1(p19);
AnalogIn Pot2(p20);

// defines to make lib thread save
#define _lock lcd_mutex.lock();
#define _unlock lcd_mutex.unlock();
Mutex lcd_mutex;

// print data into first line and wait for 1s
void thread1(void const *args)
{
    int i;
    while(true) {       // thread loop
        _lock
        LCD.locate(0,0);
        LCD.set_font((unsigned char*) Small_6);
        printf("Thread1 count: %d",i);
        LCD.copy_to_lcd();
        _unlock
        i++;
        Thread::wait(1000);
    }
}

// print data into third line and wait for 0,5s
void thread2(void const *args)
{
    int k;
    while(true) {       // thread loop
        _lock
        LCD.locate(0,20);
        LCD.set_font((unsigned char*) Arial_9);
        printf("Thread 2 count : %d",k);
        LCD.copy_to_lcd();
        _unlock
        k++;
        Thread::wait(500);
    }
}


void thread4(void const *args)
{
    int i,k,v;
    double s,a;
    k = 1;
    _lock
    LCD.rect(89,0,127,17,1);
    _unlock
    while(true) {       // thread loop
        _lock
        v = Pot1.read_u16();  // get value of pot 1
        for (i=90; i<127; i++) {           
            s = 8 * sin((long double)(i+k) /5);
            a = 8 * sin((long double)(i+k-1) /5);
            LCD.pixel(i,9 + (int)a ,0);
            LCD.pixel(i,9 + (int)s ,1);
        }
        LCD.copy_to_lcd();
        _unlock
        k++;
        Thread::wait(v/100);
    }
}


void thread5(void const *args)
{
    int k;
    while(true) {         // thread loop
    k = Pot2.read_u16();  // get the value of poti 2
    k = k >> 10;          // we need only 6 bit
    _lock
    LCD.set_contrast(k);
    _unlock
    Thread::wait(500);  
}
}

int main()
{
    int j;

    LCD.claim(stdout);      // send stdout to the LCD display
    LCD.cls();
    //start thread1
    Thread t1(thread1);
    //start thread2
    Thread t2(thread2);
    //start thread4
    Thread t4(thread4);
    Thread t5(thread5);

    while(true) {   // this is the third thread
        _lock
        LCD.locate(0,9);
        LCD.set_font((unsigned char*) Small_7);
        j = LCD.get_contrast();
        printf("contrast : %d",j);
        LCD.copy_to_lcd();
        _unlock
        Thread::wait(500);
    }

}