Hacking an RC Car

As a test, I decided to hack an existing piece of consumer electronic and control it with an Arduino. I took apart my son’s $10 toy RC car and used a wire to contact the battery’s positive terminal to random points on the circuit board until I isolated which circuits control the steering and motor. Once I located these circuits, I soldered wires to these points and connected them to pins on an Arduino.

My Arduino happens to be connected to a PS2 shield, so I made some slight modifications to my PS2 controller sketch to digitalWrite the appropriate pins to HIGH. Here’s the sketch:

#include "Shield_PS2.h"

PS2 ps2=PS2();
unsigned long time;
int fwPin = 8;
int bwPin = 9;

void setup() {
  ps2.init(9600, 2, 3);
  pinMode(fwPin, OUTPUT);
  pinMode(bwPin, OUTPUT);
  
  Serial.begin(9600);
  Serial.println("PS2 Shield initialized.");
}

void loop() { 
  // Button Status: 1 = not pressed, 0 = pressed
  // SQUARE
  if (ps2.getval(p_square) == 0) {
    printTime();
    Serial.println("SQUARE");
    digitalWrite(bwPin, HIGH);
  }
  else {
    digitalWrite(bwPin, LOW);
  }

  // CROSS
  if (ps2.getval(p_cross) == 0) {
    printTime();
    Serial.println("CROSS");
    digitalWrite(fwPin, HIGH);
  }
  else {
    digitalWrite(fwPin, LOW);
  }
}

void printTime () {
  time = millis();
  Serial.print("(");
  Serial.print(time);
  Serial.print(") ");
}