File content as of revision 0:ae2e2cabc497:

/* mbed Microcontroller Library
 * Copyright (c) 2018 ARM Limited
 * SPDX-License-Identifier: Apache-2.0
 */

#include "mbed.h"
#include "QEI.h"
#include "ros.h"

#include "geometry_msgs/Twist.h"
ros::NodeHandle  nh;

Serial pc(USBTX, USBRX);
DigitalOut led1(PA_10);
DigitalOut M1_dir(PA_8);
DigitalOut M2_dir(PB_10);
PwmOut PWM1(PB_4);
PwmOut PWM2(PB_5);

QEI rightWheel (PA_5, PA_6, NC, 624);
QEI leftWheel (PA_7, PB_6, NC, 624);

void commandCallback(const geometry_msgs::Twist& cmd_msg);
ros::Subscriber<geometry_msgs::Twist> cmd_sub("cmd_vel", commandCallback);

#define SLEEP_TIME                  500 // (msec)
#define PRINT_AFTER_N_LOOPS         20

// main() runs in its own thread in the OS
int main()
{
    PWM1.period(0.01); 
    PWM1 = 0.5;
    PWM2.period(0.01); 
    PWM2 = 0.5;
    M1_dir = 1;
    M2_dir = 1;
    while (true)
    {
        led1 = !led1;
        wait_ms(SLEEP_TIME);
        pc.printf("Right Pulses is: %i Left pulses is %i\n", rightWheel.getPulses(), leftWheel.getPulses());
        rightWheel.reset();
        leftWheel.reset();
    }
}

void commandCallback(const geometry_msgs::Twist& cmd_msg)
{
 
}