Controlling an RC car's handheld remote


3 posts
by raspberryk » Sun Sep 09, 2012 3:17 am
I'm wondering if anyone can give me some direction on how to make my idea a reality.

I'd like to end up using two of the programmable pins on the Raspberry Pi (GPIO pins I suppose) to activate two of four possible signals that are sent out from my RC car's handheld remote simultaneously.

The car that it will control is one of those dual track type cars. The remote can make the left and right track go forward or backward at the same time (one speed only). To start, I only want to send one signal from one of the GPIO pins, and make one track go one direction (to make things easy).

To help understand I've snapped some pictures and took a reading. The remote, after taking it apart looks like this on the top:

small_IMG_1498.jpg
small_IMG_1498.jpg (49.93 KiB) Viewed 2174 times


And this on the bottom:

small_IMG_1501.jpg
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When I have it on, and place the voltmeter on it, I get a reading of 4.36 volts:

small_IMG_1503.jpg
small_IMG_1503.jpg (50.05 KiB) Viewed 2174 times


So my thought is that I should have something between the GPIO pins on the Raspberry Pi, and the J1-J4 headers on the remote's board. The remote control itself uses a 9V battery. Should I use transistors to convert the 3.3V signals from the Raspberry Pi to try and match the 4.36V that is running across the remote's switches?

For what it's worth, it seems like more fun to control the remote of the unit, rather than the RC car itself. Also could be done with items like wall outlet remote controls: http://www.newegg.com/Product/Product.aspx?Item=N82E16812820011.

Thanks in advance for anyone's thoughts or help. You can see my previous work with the Raspberry Pi here to get an understanding of where I'm at with this type of stuff... its nothing ground breaking, but I've been enjoying it: http://karlherrick.com/dev/category/raspberry-pi/
Last edited by raspberryk on Sun Jan 19, 2014 9:54 pm, edited 1 time in total.
Posts: 4
Joined: Sun Sep 09, 2012 2:32 am
by Ape » Mon Dec 17, 2012 10:26 am
I have an RC car with a controller that seems to be almost identical with that one. It would be great to be able to control it with a Raspberry Pi.

I don't have lots of experience with electronics, though. Do I need some kind of a relay between GPIO pins and the controller, or should a transistor setup work? The mechanical controller switch is between the remote's 9V battery and the rest of the controller. I'd like to control that switch digitally with GPIO on Raspberry.
Posts: 1
Joined: Mon Dec 17, 2012 10:18 am
by raspberryk » Mon Dec 17, 2012 4:13 pm
There were some helpful replies given by John Beetem at the Element14 forums about this very same post. See: http://www.element14.com/community/message/59982

I haven't made the time to try and follow up on the advice though (and to be honest it is beyond what I understand currently). Anyone else that could simplify what he was saying would be great, as it seems to cut out a lot of work doing robotics.

A bunch of the wiring and logic is already done, right? I just need to make the Raspberry Pi tell the remote what to do. :-)
Posts: 4
Joined: Sun Sep 09, 2012 2:32 am