RC Car Control Transmitter with simple 433MHz modules

gistfile1.pde

// transmitter.pde
//
// Simple example of how to use VirtualWire to transmit messages
// Implements a simplex (one-way) transmitter with an TX-C1 module
//
// See VirtualWire.h for detailed API docs
// Author: Mike McCauley (mikem@open.com.au)
// Copyright (C) 2008 Mike McCauley
// $Id: transmitter.pde,v 1.3 2009/03/30 00:07:24 mikem Exp $

#include <VirtualWire.h>


// Store the Arduino pin associated with each input

// Select button is triggered when joystick is pressed
const byte PIN_BUTTON_SELECT = 2; 

const byte PIN_BUTTON_RIGHT = 3;
const byte PIN_BUTTON_UP = 4;
const byte PIN_BUTTON_DOWN = 5;
const byte PIN_BUTTON_LEFT = 6;

const byte PIN_ANALOG_X = 0;
const byte PIN_ANALOG_Y = 1;

int x_position;
int y_position;


char msg[19]="X0000Y0000A0B0C0D0";
int led = 13;

void setup() {
  pinMode(led, OUTPUT);     
  Serial.begin(9600);

  Serial.println("setup");

  pinMode(PIN_BUTTON_RIGHT, INPUT);
  digitalWrite(PIN_BUTTON_RIGHT, HIGH);

  pinMode(PIN_BUTTON_LEFT, INPUT);
  digitalWrite(PIN_BUTTON_LEFT, HIGH);

  pinMode(PIN_BUTTON_UP, INPUT);
  digitalWrite(PIN_BUTTON_UP, HIGH);

  pinMode(PIN_BUTTON_DOWN, INPUT);
  digitalWrite(PIN_BUTTON_DOWN, HIGH);

  pinMode(PIN_BUTTON_SELECT, INPUT);
  digitalWrite(PIN_BUTTON_SELECT, HIGH);


  // VirtualWire Initialise the IO and ISR
  vw_set_ptt_inverted(true); // Required for DR3100
  vw_setup(2000);	 // Bits per sec
}

void loop() {

  int thous;
  int huns;
  int tens;
  int ones;
  char digitsascii[5] = "0000";
  
  x_position = analogRead(PIN_ANALOG_X);
  y_position = analogRead(PIN_ANALOG_Y);

  // Format is XnnnnYnnnnAnBnCnDn
  // X is X position of joystick as 4 digits
  // Y is Y position of joystick as 4 digits
  // A is A button on joystick. 0= Not pressed. 1 = pressed
  // B is B button on joystick. 0= Not pressed. 1 = pressed
  // C is C button on joystick. 0= Not pressed. 1 = pressed
  // D is D button on joystick. 0= Not pressed. 1 = pressed
  
  //First convert X pos to 4 ascii characters (48 is decimal ASCII code for '0')
  thous = x_position/1000;
  msg[1]=thous+48;
  huns = (x_position - (thous*1000))/100;
  msg[2]=huns+48;
  tens = (x_position - (thous*1000) - (huns*100))/10;
  msg[3]=tens+48;
  ones = x_position - (thous*1000) - (huns*100) - (tens*10);
  msg[4]=ones+48;

  //Then convert Y pos to 4 ascii characters
  thous = y_position/1000;
  msg[6]=thous+48;
  huns = (y_position - (thous*1000))/100;
  msg[7]=huns+48;
  tens = (y_position - (thous*1000) - (huns*100))/10;
  msg[8]=tens+48;
  ones = y_position - (thous*1000) - (huns*100) - (tens*10);
  msg[9]=ones+48;

  // Will implement buttons laters
  digitalWrite(led, HIGH);
  Serial.println(msg);
  // send string to receiver (actually just broadcast. No concept of 1-1 comms with these TX/RX modules
  vw_send((uint8_t *)msg, strlen(msg));
  vw_wait_tx(); // Wait until the whole message is gone
  delay(100);
  digitalWrite(led, LOW);
  delay(100); 
}