Assembly

Let’s upgrade some simple car. Here we have the nice car for 1:53 scale. This car can go forward, backwards and make turns to the left and the right. The car is controlled with some remote. If you have several of those tiny cars you have to have a separate remote for each of them.

Requisites:

• Previously created board.
• Smartphone.
• Smartphone application.
• Some car for hacking.
• Soldering iron and some solder.
• Pliers

So let’s install our constructed Bluetooth module inside of this tiny car and get rid of remote controller, and as a bonus, we could use just one phone for controlling all cars. The cars’ sharing with the friends could be just by passing a car and installing an app on the smartphone.

So let’s open this, car. First we have to remove batteries. Inside we have the printed circuit board for receiving commands from remote and controlling the car. The car is driven by small brushed motor; the steering is controlled by two electro-magnets. Then we want to make a turn, the controller applies some current on one of the magnets ant magnet attracts the steering magnet to the desired side and it in turn turns the wheels.

So the next step is to remove old control board. We have to disconnect motor – cut be cut or de-soldered, it’s recommended to leave them as long as possible (in this case motor wires are blue and white ones). After that, we have to disconnect battery wires – cut the red and black wires (or de-solder) from the board. The black one goes directly from the battery contacts and the red one goes from the power switch. Finally, we have to disconnect steering magnets. Those magnets are connected with some tiny wires. Each magnet is connected with 2 wires, depending on how those two wires are connected magnet attracts or pushes steering magnet (reverse the battery for push). In this car, the + sides of both of the magnet is connected to the VCC pad on the control board (it’s recommended to leave those two wires connected together, as we will need than to solder to the new board together as well). The other two wires control the left and right side magnets, those has to be disconnected as well.

The next step is adding connectors. The connectors can be added to the motor and power wires. In the example selected connectors does not need soldering, they required just some work with pliers. We have to strip some isolation from the wire and add metallic connector and its plastic housing.

The steering wires are more problematic, they are so tiny that there is no easy way to add connectors, so they can be soldered directly to the replacement board. The two connected wires from magnets have to be soldered to the power pad (or could be soldered directly to the battery positive side wire on the car). The remaining wires from the magnets has to be soldered to the two pads on the board – top pad is for the left magnet wire, the second pad for the top is for the right magnet wire.

Finally, we have to just plug power connector to the power headers on the board and motor wires to the motor connector, place the board inside the card, and reassemble car back (put the cover and screw it).

Now it’s time to launch the Smartphone app, turn the car on and start racing.

Troubleshooting

• Car does not start – check if batteries are installed, check if power wires are connected to the swich, check if power connector to the board is not reversed.
• Car goes backwards instead of forward – reverse motor connector.
• Car turns to the left instead of right – check if magnets wires are soldered to correct pads (just reverse them).
• Steering does not work – check if two power wires from the magnets are together soldered to the VCC pad.