1. Learn how to use microcontroller
The microcontroller I’m using is an Arduino. With out the Arduino there is no way I would be able to communicate with the toy. Later, a Bluetooth module will be used so I can communicate with the Arduino wirelessly. To learn more about the Arduino you can refer back to the PROGRAMMING ARDUINO page.
A multimeter is essential in designing electronic circuits. A multimeter is really easy to use. . The main thing you will use the multimeter for is to measure resistance, current, or voltage. There are two probes, one positive, one negative which you place on corresponding wires on the circuit where you want to measure. After this the measured values will be displayed on the screen.
2. Learn how the toy works
This particular toy is a fire truck. The fire truck has a wired controller with 11 different functions. In order to learn how it works we need to very carefully open it up and see how everything is wired; what goes to what, what does it do when I press this etc..
3.Build adapter board
Before I could build the adapter board I needed to learn how to solder. Soldering is really important in order to get all the wires in place so they won’t touch. If you have wires touching it could cause a short which could ruin your circuit. The way you use the soldering iron is to first turn it on and let the soldering iron heat up. When it’s ready, hold the tip of the soldering iron on the area you want to solder. After a few seconds you melt the solder onto the circuit. Once is melted it it should stay on the area you placed it and it will cool down and harden after a few seconds. If this is not clear enough here is a link to a video on YouTube where all of this is explained really well. http://www.youtube.com/watch?v=BLfXXRfRIzY
The driver board I’m building is a transistor based driver. The transistor has three different pins; collector, base, and emitter. What the three pins do is allow the transistor to act like switch with an electrical signal that you send out. In this case we would send out the electrical signals with the Arduino. After the Arduino send the voltage and passes through the driver board it goes to a relay board. What the relay board allows us to do is to keep all of the functions of the truck to be connected to ground since this is how the toy operated before. When one of the relays gets a voltage from the Arduino it turns on allowing the relay to turn on a function on the truck.
4. Program the cell phone
There are two different ways we can communicate with and Arduinio. One is with cables and the other with Bluetooth. In this case we needed to use Bluetooth because if we used a cable we would not have changed much from the original fire truck since it already uses cables. This particular Bluetooth module has four different pins. The four different pins are transmitter, receiver, power, and ground. The way you connect this to the Arduino is by putting the transmitter for the Arduino to the receiver of the Bluetooth, then you connect the receiver of the Arduino to the transmitter of the Bluetooth. Finally you connect ground of the Arduino to ground of Bluetooth and power from Arduino to power of Bluetooth. Now there should be a red light blinking. This means your Bluetooth is ready to use. Next, on your computer, setup the Bluetooth just like you would any Bluetooth device. If you have done this correctly the light on the Bluetooth should not blinking anymore. This means the pairing was successful and your Bluetooth module is ready to use.
App inventor is the website i’m using to create the app for the smart phone. This is a free very easy tool to use. The fist page has has the screen of an Android, this is used for the design of the app. On the right of the screen you have all the different option you can put on the app. All you do is drag them and put them where you want them to be in the screen. On the second page called blocks is where you actually do all the logic of what you the app to do. With out this your app would basically do nothing. In the right of this page you have all the thing you added in the designer part, when you press them it will give options of what you can do them. A good thing about App Inventor is that you don’t need a cable to install the app into the phone, you can do it over WiFi. You can go to connect AND then AI companion to test your app and if you like it, you can go to build and App(provide QR code for .apk) and it will install the app in you phone. Once its done the app is ready to use.