File content as of revision 66:1664ee92539d:

/***************
RS422 master libraly

RS422 name(tx, rx)
tx : mbed_tx
rx : mbed_rx

put(int id, float m1_duty, float m2_duty)
id : 0 - 254
duty : -1.0 - 1.0

****************/


#define start_signal    0b11111111
#define cool_time       0.0004

class RS422
{
public :
    RS422(PinName mbed_tx, PinName mbed_rx) : Rs422(mbed_tx,mbed_rx) {
    }

    void begin(int baudrate) {
        Rs422.baud(baudrate);
        timer.attach(this, &RS422::put_time, cool_time);
    }

    void put(int id, float m1_duty, float m2_duty) {
        if (flag == 0) {
            ID = id;
            if (m1_duty < 0) {
                m1_data = 0b10000000;
            } else {
                m1_data = 0;
            }
            if (m2_duty < 0) {
                m2_data = 0b10000000;
            } else {
                m2_data = 0;
            }
            m1_data += fabs(m1_duty) * 100;
            m2_data += fabs(m2_duty) * 100;

            check_sum = (id + m1_data + m2_data) & 0b01111111;
        }
        flag = 1;
    }

private :
    Serial Rs422;
    Ticker timer;

    short flag;
    int counter;
    int m1_data,m2_data,check_sum;
    int ID;

    void put_time() {
        switch (counter) {
            case 0 :
                Rs422.putc(start_signal);
                break;
            case 1 :
                Rs422.putc(ID);
                break;
            case 2 :
                Rs422.putc(m1_data);
                break;
            case 3 :
                Rs422.putc(m2_data);
                break;
            case 4 :
                Rs422.putc(check_sum);
                break;
            default :
                break;
        }
        counter ++;
        if(counter >= 5) {
            counter = 0;
            flag = 0;
        }
    }
};