/* Crawler Slave
 *  
 *  This code runs on the crawler i2c network
 *  and provides a cleaner, less CPU intensive control over PWM devices.
 */

#include <Wire.h>
#include <Servo.h>

// This servo is used to wipe and clean the camera lens
Servo windowWiperServo;

// This is a variable capable of storing up to 4 items
char instruction[4] = "";

void setup() {
  // Attach the wiper servo to pin 9
  windowWiperServo.attach(9);

  // This is only useful for debugging
  Serial.begin(9600);

  // This is the address the pi will speak to us at
  Wire.begin(0x8);
  
  // Call receiveEvent when data received                
  Wire.onReceive(receiveEvent);

  Serial.print("Finished Setup.");  
}

// Just loop to keep the running code alive, and wait for events to happen.
void loop() {
  delay(50);
}

// This method runs when we receive a message
void receiveEvent(int n) {
  for (int i = 0; i < n; i++) //n is equal to the number of data bytes received
  {
    instruction[i] = Wire.read();
  }
  
  Serial.print(instruction);
}