I have built a model rocket launcher that is wireless. I have been using my custom launcher for some time and I get tired of dealing with the long wire that always seem to get tangled.

I decided to build I wireless controller with an arduino and an android device that would launch the rocket from a distance without all of the long cables. This project was fairly cheap costing under $20.

For the wireless controller I used the following components:

Arduino Uno (Mini/micro will also work) - $5.99

HC-06 Bluetooth Module - $3.50

1ch Relay - $3.75

8x AA Battery Holder - $1.29

Toggle Switch (for case) - $2.10

2 Wires with alligator clips at one end and a box to put it in.

Tools:

exacto knife
soldering iron

Step 1: Build the Controller

First you will need to wire up the HC-06 bluetooth module. Connect ground to one of the GND pins on the arduino and connect the TXD to the RXD and the RXD to the TXD.

NOTE: I found it helpful to put some type of switch between the VCC on the HC-06 and the 5V on the arduino. If you do not do this you will have issues reprogramming the arduino with the HC-06 connected. Have the switch open (off) to program and closed (on) during normal operations.

Next wire up the relay. Make sure the pin marked S on the relay is connected to pin 8 on the arduino. After the relay is connected to the arduino you can wire the negative terminal on the battery to the common terminal screw on the relay.(This is normally the middle one)

Step 2: Program the Arduino

Below is the sketch I used.

//Remote rocket launcher ***JDBWizzard***

int firePin = 8; //Pin connected to relay

void setup()

{

pinMode(firePin,OUTPUT);

Serial.begin(9600);

}

void loop() {

if(Serial.available()>0)

{

if(Serial.read() == 'l') //Lowercase L sent from android app

{

digitalWrite(firePin,HIGH);

delay(2000); //Can be raised if not firing

digitalWrite(firePin,LOW);

}

Step 3: Put It All Together

Now that you have the controller together and programmed we need to put it together.

Take the box you choose to hold everything and make a hole to feed the ends of you wire without the alligator clips through. Connect one wire directly to the positive lead on your battery pack.

Mount the toggle switch somewhere on the box. Connect the other wire to one lead on the toggle switch. Now connect a piece of wire from the other lead on the toggle switch to the terminal screw on the relay label NO (normally open).

To power the arduino you could wire a male DC jack to the battery pack and plug it in to the connector. I will be opting to use a battery backup for a phone and connecting it with a usb cable.

Step 4: Download the App and 3..2..1....LAUNCH

You can download the app from the google play store called Remote Rocket Launcher.

You can find the source code here. Fell free to build on it or make any changes.

Source code for the app will be available soon. You can use any app for arduino bluetooth as well. After you connect you just need to send l (Lowercase L) to the arduino to launch.

To test i used a LED with a 100ohm resistor instead on an igniter.

Enjoy.