Look for serial device
Drive
Arduino code: int m1f = 13; //motor 1 forwards int m1r = 12; //motor 1 reverse int m1pwm = 5; //motor 1 mark-space int m1drive = 0; //We set these pins as outputs in the setup routine void setup(){ pinMode(m1f, OUTPUT); pinMode(m1r, OUTPUT); digitalWrite(m1pwm,HIGH); Serial.begin(9600); } void loop() { if (Serial.available() > 0) { m1drive=Serial.read(); if(m1drive>127){m1drive-=256;} //this restores the sign bit setdrive(m1drive,m1f,m1r,m1pwm); } } int lim(int x){ if(x>255){x=255;} if(x<-255){x=-255;} return x; } void setdrive(int m,int f, int r,int pwm){ if(m>0){ digitalWrite(f,HIGH); digitalWrite(r,LOW); }else{ digitalWrite(f,LOW); digitalWrite(r,HIGH); } analogWrite(pwm,lim(2*abs(m)); }