Remote Control Tank Drive Car

This is a guide on how to make a remote control tank drive car. The set I will be using to make the car today is a simple tank drive car kit, with a light sensor to follow a path. Your car does not need the light sensor, but a tank drive car is needed for the method we are using today. This first part of the guide is made to suit those working with the same kit I am. We will make it in three stages. The first being the car itself, then a design of the remote and receiver on a breadboard, and finally the remote and receiver. The remote and reciever use the HT12D/E integrated circuit chips. The HT12E chip is the encoder, and the HT12D chip is the decoder. The encoder will be used for our remote, and the decoder for the reciever that will be attatched to the motor driver. The encoder sends a series of 1s and 0s to the decoder, after encoding them so that other radio devices and recievers dont pick up on them. The decoder recieves the signal via radio and decodes it, before sending an output through one of four pins. These two circuits are good for our car for two reasons. The four outputs of the decoder are perfect for a tank drive car. L-forward, L-back, R-forward, R-Back.

Supplies

For the Car

1x Circuit board

1x battery pack

2x gearbox motors

2x Wheels

2x Rubber wheel rings

1x 3cm Bolt

2x Red LEDs

2x White LEDs

1x Button

1x Nut

1x Cap

2x 1cm screw

4x Wires 2x photo resistors

1x Lm393 ic chip

2x 100 uf capacitors

2x 103 potentiometers

2x s8550 transistors

2x 1k ohm resistors

2x 10 ohm resistors

2x 3.3k ohms

4x 51 ohm resistors

1x Soldering Iron

1x Spool of solder

For the Remote and Reciever Design

1x Breadboard

1x 5 V power supply

1x Spool of firm copper wires

1x Wire Stripper

1x Pair of side cutters

1x HT12E IC chip

1x HT12D IC chip

1x 1M ohm resistor

1x 47k ohm resistor

2x 270 ohm resistor (other values are acceptable provided they are close to 300 ohms)

5x LEDs

1x 433MHz Rx reciever chip

1x 433MHz Rx Sender chip

1x Motor driver chip

2x Motors

4x Buttons

10x Wires with one female pin reciever and one male pin

For the Final Remote and Reciever

1x HT12E IC chip
1x HT12D IC chip

1x 1M ohm resistor

1x 47k ohm resistor

1x 270 ohm resistor (other values are acceptable provided they are close to 300 ohms) (Optional)
4x LEDs (Optional)

1x 433MHz Rx reciever chip
1x 433MHz Rx Sender chip

1x Spool of eletrical wires

1x Pair of side cutters

1x Pair of wire strippers

1x Motor Driver

1x Three pin male to female socket

1x Four pin male to female socket

2x Blank circuit boards

1x Soldering iron

1x Spool of solder

4x Buttons

Step 1: Making the Car

The set I will be using to make the car today is a simple tank drive car kit, with a light sensor to follow a path. Your car does not need the light sensor, but a tank drive car is needed for the method we are using today. This first part of the guide is made to suit those working with the same kit I am.

1. It is generally best to solder in the shortest components of a circuit first, in order to get a nice and clean soldering, so we will be soldering resistors in first.

2. Solder in transistors

3. Solder in capacitors

4. Solder in potentiometers/variable resistors

5. Solder in the IC chip

6. Solder in the button

7. Solder in LEDs and sensors. Make sure that the white LEDs are about a centimetre off the board and the sensors about a further 0.5 centimetres further out.

8. Place the rubber rim around the wheels, then screw the wheels to their respective motor with the short screw

9. Solder the wires to the pads and then to the motors

10. Test the wires are the correct way around by powering the car and holding the sensor to a black surface. If the wheels are spinning clockwise when held in the right direction, then the wiring is correct. If not, fix it.

11. Place the motor to the boards, being sure to check which way it goes and to use the adhesive backing

12. Screw in the bolt, and secure it with the nut. Then put the cap on the bottom on the screw.

13. Test. Below is a demonstration of my car following a set path using the tank drive motors.

Step 2: Designing the Remote and Receiver

This stage we are designing the circuits we will need for our remote control and receiver. We will be using a breadboard and the rest of the components under this section in the supplies. You may find it useful to look at this diagram to help with my instructions to make the circuit.

1. Make sure you are familiar with the function of a breadboard. If you are unsure on how to use one, see this video here (which I definitely made 100%) https://www.youtube.com/watch?v=6WReFkfrUIk

2. Cut and strip about twenty to twenty five wires of about 5 cm in length and one of about 15 cm in length for our breadboard. Make sure the wire you have is firm enough to stick into the breadboard, as specified in supplies.

3. Place your encoder and decoder chips at separate ends of the breadboard, making sure to put one row of legs on one side of the channel and the other on the other side for both chips. For this, I chose to utilise both sides of the breadboard, making the left-hand side my negative path and my right hand side the positive path. I chose to do this, but you may wish to use the positive and negative paths on one side for the sake of neatness

4. Begin connecting the wires without components to ground and to power as shown in the diagram. On the encoder, pins 2,4,9 and 14 need to be connected directly to ground, and pin 18 needs to connect directly to power. On the decoder , pins 2,4 and 9 need to be connected directly to ground, and pin 18 needs to connect to power.

5. On the encoder, connect pin 16 to pin 15 using the 1m ohm resistor. On the decoder, connect pins 15 and 16 with the 47k ohm resistor.

6. On the encoder, connect pins 10 to 13 directly to ground. These pins will be connected to buttons later, but for the sake of simplicity, we will be just pulling out the wires for now.

7. Somewhere else on the board, place four LEDs, with each foot of each LED on a different row. Via the negative legs of the LEDs, connect one to pin 10 of the decoder, one to pin 11, one to pin 12 and one to pin 13. Connect the positive sides to the 270 ohm resistor which then connects to the positive voltage.

8. Using the long wire, connect pin 17 of the encoder to pin 14 of the decoder. When the power is connected to the breadboard, and you remove one of the button replacing wires on the encoder, a light should turn on. If your lights turn off when a wire is disconnected from ground, and turn on when it is reconnected, try swapping the direction of your LEDs

8.5. This step is optional, but is very useful for the next few stages. This step is setting up a VT light, which will be useful in telling you if your decoder is actually receiving information. Connect a light on the positive side to in 17 on the decoder. Connect the negative side to another resistor and then to ground.

9. Remove the wire connecting the encoder and the decoder. From now on, we will be sending information between the two using a radio sender and receiver rather than a wire.

10. Take six of the ten wires with the male pin one end and the female on the other. Connect two to power, and two to ground. Connect one to pin 17 of the encoder and the last one to pin 14 of the decoder.

11. Take your radio chip. The small one is the sender and the big one is the receiver. On the sender, with the three pins facing towards you, connect the left most pin to pin 17 using the wire, the middle one to power and the right most one to ground. On the receiver, connect the left most pin to power, the right most pin to power, and one of the middle ones to pin 14 of the encoder. When plugged into power, the VT light should turn on, indicating there is a signal being received. If this is not the case, check the radio chips are connected properly. When one of the wires that function as buttons are removed, one of the LEDs should turn on.

12. Place four buttons in a column going down the breadboard, making sure nothing is touching them. You want to have one side of the buttons legs on one row and the other legs on another row. None of the buttons should be on the same row. Take the wires that were functioning as buttons, and connect each to one row of each of the buttons. Then get four more wires, and connect the other side of each button to ground. When plugged back into power, the circuit should function the same, only with the buttons working instead of having to remove wires.

13. Take the motor driver circuit, and find the wires. There should be two for each motor, one positive and one negative. Solder them to the motors in your car in the correct manner.

14. Take the remaining four wires with a female adapter and a male pin. Connect the male pins to the decoder, one to each of the rows with pin 10, 11, 12 and 13. Connect the pins to the motor driver. When the circuit is powered, and the buttons pressed, the wheels on the car should move either forwards, backwards or not at all depending on the buttons you are pressing. Once that is done, take note of which pins move the motor in what direction. This will be important for aligning the buttons in the next stage of our project.

Step 3: Making the Remote Control and Receiver

With this stage of our project, the instructions apply to both the sender and the receiver until stated otherwise.

1. Solder in all non wire components. For the controller, be sure to place the buttons in an arrangement that would be comfortable to use for a tank drive car. The rest of the compenents for the controller should also follow this rule. For the reciever, positioning of components doesnt matter too much. Place it however you wish, or you can copy my arrangement in the photos above. The LEDs are an optional step, and very useful for trouble shooting. I had to remove mine because of some issues with wires touching.

2. Solder in all wires that lead to ground. You may find it useful to use the guide attatched to the last step, or to copy off your breadboard design. I have colour most of my wires. Black wires go straight to ground. Red wires go to VCC, and yelllow wires go to components. Another tip with wires is to make them just longer than they need to be. Wires that are too long can create alot of mess.

3. Solder in wires to VCC.

4. Solder in other wires.

5. Find the pins which connect to the LEDs (if you decided to use them) on the reciever. Solder one wire to each. Proceed to connect those wires to your motor driver, checking with your observations from the breadboard to make sure each wire goes where it is meant to. If you make a mistake, dont worry, you can resolder and place it again.

7. Solder the motors of your car to the motor driver.

8. Connect the remote control, the reciever and the motor driver to power. I used some battery packs i had lying around.

9. Test your car. If it does not work, make sure that the wires are all connected properly, and that none have short circuited. Also check that the radio chips are connected properly with their sockets. If nothing works, idk, im not a tech teacher. Try find an oscilloscope if you have one and test if any output is coming out of your reciever chips at the wires which connect to your motor driver.

10. Attatch the motors back to your car if you havent already. Congratulations. You have a working remote control car.

11. Download this guide as a PDF and put it in a report before submitting to your teacher.