File content as of revision 6:b8a1fa98707e:

#include "wheelchair.h"

AnalogIn x(A0);
AnalogIn y(A1);

DigitalOut off(D0);
DigitalOut on(D1);
DigitalOut up(D2);
DigitalOut down(D3);

char c;
bool manual = false;
bool received = false;
Serial pc(USBTX, USBRX, 57600);

Timer t;
EventQueue queue;

//MPU9250 imu(D14, D15);
Wheelchair smart(xDir,yDir, &pc, &t);
Thread thread;

ros::NodeHandle nh;
geometry_msgs::Twist commandRead;
ros::Publisher chatter("chatter", &commandRead);

void handlerFunction(const geometry_msgs::Twist& command)
{
    if(command.linear.x >0) {
        c = 'w';
    }
    received = true;
}

ros::Subscriber<geometry_msgs::Twist> sub("cmd_vel", &handlerFunction);


void setupNode()
{
    nh.initNode();
    nh.subscribe(sub);
    nh.advertise(chatter);
}

int main(void)
{
    on = 0;
    off = 0;
    
    queue.call_every(SAMPLEFREQ, &smart, &Wheelchair::compass_thread);
    t.reset();
    thread.start(callback(&queue, &EventQueue::dispatch_forever));
    setupNode();
    while(1) {
        if( received) {

            if( c == 'w') {
                pc.printf("up \n");
                smart.forward();
            }

            else if( c == 'a') {
                //pc.printf("left \n");
                smart.left();
            }

            else if( c == 'd') {
                //pc.printf("right \n");
                smart.right();
            }

            else if( c == 's') {
                pc.printf("down \n");
                smart.backward();
            }

            else if( c == 'r') {
                smart.turn_right(90);
            }

            else if( c == 'l') {
                smart.turn_left(90);
            }

            else if( c == 't') {
                char buffer[256];
                pc.printf ("Enter a long number: ");
                fgets (buffer, 256, stdin);
                int angle = atoi (buffer);

                if(angle == 0) {
                    pc.printf("invalid input try again\n");
                } else {
                    smart.pid_turn(angle);
                }

            } else if(c == 'o') {
                pc.printf("turning on\n");
                on = 1;
                wait(1);
                on = 0;
            } else if(c == 'f') {
                pc.printf("turning off\n");
                off = 1;
                wait(1);
                off = 0;
            }

            else if( c == 'm' || manual) {
                pc.printf("turning on joystick\n");
                manual = true;
                t.reset();
                while(manual) {
                    smart.move(x,y);
                    if( pc.readable()) {
                        char d = pc.getc();
                        if( d == 'm') {
                            pc.printf("turning off joystick\n");
                            manual = false;
                        }
                    }
                }
            }

            else {
                pc.printf("none \n");
                smart.stop();
            }
        }

        else {
            //        pc.printf("Nothing pressed \n");
            smart.stop();
        }
        wait(process);
    }

}