File content as of revision 1:eb499e2a1b9b:

#include "mbed.h"
#include <HX711.h>

CAN can1(PD_0, PD_1);
CAN can2(PB_5, PB_6);
DigitalOut led1(LED1);
DigitalOut led2(LED2);
//FlashIAP flashIAP;

/* scale */
HX711 hx711(PB_11, PB_10);

struct ScaleCalibrationData {
  unsigned int calibrationWeight;  // the weight (g) used for calibration for example 1000g or 10g. The maximum value is 3000. 
  long offsetValue;       // the value for scale offset
  float scaleValue;       // the ADC increment for 1g  
  unsigned char checksum;  
};
unsigned int calibration_ADC_value;
//#define CALIBRATION_VALUE   10    // 10g as the calibration weight
#define WEIGHT_DIFFERENCE   200   // 10g ADC value minimum difference
#define CALIBRATION_WEIGHT  2000    // calibration weight

ScaleCalibrationData customVar;

long zero_value;
long calibration_value;
unsigned int calibration_times; // must calibration 3 times
unsigned int calibration_done = 0;
float scale_value;

/* scale */
void scaleCalibration()
{
    printf("Start Calibration.\r\n");
    calibration_done = 0;
    if (!calibration_done)
    {
        led1 = 1; 
        led2 = 0;
        customVar.calibrationWeight = CALIBRATION_WEIGHT;
        zero_value = hx711.averageValue(10); // skip first 10 readings
        zero_value = hx711.averageValue(20);
        printf("zero_value=%d \r\n", zero_value);
        calibration_value = 0;
        scale_value = 0;
        calibration_times = 0;
        
        while (( calibration_times < 5))
        {
        
            calibration_value = hx711.averageValue(20);
            if (calibration_value > (zero_value + WEIGHT_DIFFERENCE))
            {
                calibration_times++;
            }
            else
                calibration_times = 0; 
        }
        printf("calibration_value=%d calibration_times=%d\r\n", calibration_value, calibration_times);
        if (calibration_times >=5)
        {
            // calibration is OK
            led1 = 0;
            led2 = 1;
            calibration_times = 0;
            scale_value = (calibration_value - zero_value) / customVar.calibrationWeight;
            customVar.offsetValue = zero_value;
            customVar.scaleValue = scale_value;
//               EEPROM.put(0x00, customVar);
            hx711.setOffset(zero_value);
            hx711.setScale(scale_value);      // this value is obtained by calibrating the scale with known weights; see the README for details
            calibration_done = 1;
        }
    } 
}

int a = 0;
int b = 0;

void print_char(char c = '*')
{
    printf("%c\r\n", c);
    fflush(stdout);
}

Thread thread;


CANMessage  msg;


InterruptIn button1(USER_BUTTON);
volatile bool button1_pressed = false; // Used in the main loop
volatile bool button1_enabled = true; // Used for debouncing
Timeout button1_timeout; // Used for debouncing

// Enables button when bouncing is over
void button1_enabled_cb(void)
{
    button1_enabled = true;
}

// ISR handling button pressed event
void button1_onpressed_cb(void)
{
    if (button1_enabled) { // Disabled while the button is bouncing
        button1_enabled = false;
        button1_pressed = true; // To be read by the main loop
        button1_timeout.attach(callback(button1_enabled_cb), 0.3); // Debounce time 300 ms
    }
}

void print_thread()
{
    while (true) {
 #if 1       
        if(can1.read(msg)) {
            print_char();
            printf("got message id=%d 0x%08x\r\n", msg.id, msg.id);
//            b = *reinterpret_cast<int*>(msg.data);
            b = msg.data[0];
            printf("got data %d 0x%08x \r\n", b, b);
            if(msg.id == 1337) {
                led2 = !led2;
 
                b = *reinterpret_cast<int*>(msg.data);
                printf("got message %d\r\n", b);
                if(b % 5 == 0)
                    led2 = !led2;
             }
        }
//        wait(0.2);
#endif
    }
}

int main()
{
    printf("\n\n*** RTOS basic example ***\n");
    scaleCalibration();
    thread.start(print_thread);

//    flashIAP.init();
//    printf("Flash start address: 0x%08x Flash Size: %d\r\n", flashIAP.get_flash_start(), flashIAP.get_flash_size());
//    can1.reset();
//    can2.reset();
//    can1.frequency(100000);
//    can2.frequency(100000);
    //button1.mode(PullUp); // Activate pull-up
   button1.fall(callback(button1_onpressed_cb)); // Attach ISR to handle button press event

    int idx = 0; // Just for printf below

    while(1) {
        if (button1_pressed) { // Set when button is pressed
            printf("scale value %f. \r\n", hx711.getGram());
            button1_pressed = false;
            printf("Button pressed %d\n", idx++);
            can1.write(CANMessage(1337, reinterpret_cast<char*>(&a), 1));            
            led1 = !led1;
            a++;
        }
    }
 #if 0
    while(1) {
 //       can1.write(CANMessage(1337, reinterpret_cast<char*>(&a), sizeof(a)));
#if  
        can1.write(CANMessage(1337, reinterpret_cast<char*>(&a), 1));
#endif        
        printf("loop a=%d\n", a);
        led1 = !led1;
        a++;
        wait(0.2);
    }
#endif    
}