How to make a wireless transmitter and receiver for a remote controlled car

[dark_tyrant]

Hey guys. I was wondering if there is a way to make a wireless transmitter and corresponding receiver using old parts, e.g. from an old DVD and its remote, or maybe a Radio set. I also have an old laptop that doesn't work anymore, though it is really old (must have been made in the 90s or early 2000s). I want to make a small remote controlled car for the school science exhibition and need a circuit for wirelessly turning the DC motor on and off. I would just go and buy one in a shop somewhere but I was wondering if there was a way to make one myself, which would earn more marks. Is it possible? Thank you very much

 

[Alabalcho]

You can still make one and "earn marks", but you have to understand how (remote) control works:
- you have an object you want to (remotely) control
- you have another object communicating with the controller one, **somehow*. This can be over radio waves, using wires, using (ultra) sound, using (infra-red) light, or a trained monkey at the wheel.

And this **somehow** is the key. Having old broken laptop, DVD player etc won't help a lot. You might be able to pull out some parts which could do some job (eg motors), but from there on you need strong electronic and/or programming skills to finish your task.

Go to a site like instructables.com, there are ton of projects of various difficullty. If I was you - I would get cheap RC car, and hack it to be operable thru a smartphone. Arduino's and RPi's are cheap enough for these tasks.

 

[Ralston18]

Very good chance that you will be able to do so.

The key being that you can determine or find out what the various DVD remote buttons actually transmit. And then make that transmission something that the radio controlled car will respond to.

Many years ago I used BASIC (a programming language) to control a radio controlled car via the RS-232 port on an Atari 800 computer.

All I had to do is to is use the RS-232 (serial) port to provide the necessary voltage (9v) to the radio controller in lieu of a 9v battery.

The requirements that you must address are very similar.

I do not believe that control via Remote -----> laptop ------> radio controlled car will be very viable.

Laptop -------> radio controlled car controller ------> radio controlled car is much more straight forward and viable.

Find a way to connect and control the radio car's controller via the laptop. E.g., connect the original radio controlled car controller battery wires to the USB Port on the old laptop instead of a battery. You will need to use a USB cable between the old laptop and the radio controlled car. Voltages may be a problem...

Then you write code that turns the voltages on or off as necessary.

Write some code that can turn on or off that voltage(s) so the transmitter "transmits" and the car responds.

You will be dealing with USB ports and different voltages. My immediate thought is that the USB ports may not be capable of providing the necessary voltage to the radio car's controller. You may need an interim power source - i.e. a USB wall-powered hub).

The key is to identify port on the old laptop that you can use and subsequently control the power to the remote control car controller.

My BASIC program "recorded" a manual run (via joystick) of the car and then played it back. Once I understood the time and voltage correspondence I could literally write a pattern of movements for the radio controlled car.

Lots of fun.