File content as of revision 6:004e6174445a:

#include "mbed.h"
#include "GMD.hpp"

char read_address() {
    const size_t din_num = 4;
    DigitalIn din[] = {
        DigitalIn(dp26),
        DigitalIn(dp25),
        DigitalIn(dp18),
        DigitalIn(dp17)
    };
    
    char address = 0;
    size_t address_offset = 0x08 << 1;
    for (size_t i = 0; i < din_num; ++i) {
        address |= din[i].read() << (i + 1);
    }
    return address + address_offset;
}

int main(){
    I2CSlave i2c(dp5, dp27);
    i2c.address(read_address());
    basic_motor_driver md(dp1, dp2, dp9);
    
    while (true){
        char buf;
        switch (i2c.receive()){
            case I2CSlave::ReadAddressed:
                break;
            
            case I2CSlave::WriteGeneral:
                break;
            
            case I2CSlave::WriteAddressed:
                i2c.read(&buf, 1);
                
                /*
                float p = (buf & 0x80) ? -1.0f : 1.0f;
                p *= (buf & 0x7F);
                p *= 1.0f / 0x7F;
                */
                
                md.set(static_cast<int8_t>(buf) / 127.0f);
                break;
                
            case I2CSlave::NoData:
                break;
        }
    }
}