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Simple circuit to turn robot chassis with DC motors into RC car? Answered

I want to convert a robot chassis with two DC motors, like this one:


into a basic RC car. Ideally, I'm looking for an off-the-shelf solution consisting of a remote with two joysticks (for tank-style steering) and a paired breadboard-compatible receiver that outputs, for each channel, either (a) an analog voltage (say from 0-5V) or (b) a PWM signal (from 0-100% duty cycle). Those signals would be used to control the motors through two transistors.

The closest thing I've got so far was recommended by a colleague - a paired remote control and receiver module:



However, that receiver outputs a PWM signal intended for servo control. My understanding of servo PWM signals is that they don't actually swing fully from 0-100% duty cycle, so that wouldn't necessarily work (i.e. if it only drops to 25% duty cycle, the robot would never actually come to a full stop).

Any suggestions for a simple, off-the-shelf solution would be appreciated. I realize there are probably more complicated ways to do this (rip apart an old RC car and steal the circuitry, use an Arduino, etc), but this is for middle-school kids in an afterschool setting, so I need to minimize cost and complexity.


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Ben Finio
Ben Finio

6 years ago

Update: did some searching and found a solution from Adafruit that would kind of work, but isn't exactly what I want. I could use a key fob:


plus RF receiver:


the video at the bottom of either page shows them being used to turn LEDs on and off, so it would be easy to just do that with transistors+motors instead. The obvious downside is there's no speed control and the motors would just be on/off. So, while it's better than nothing, I'd still prefer an analog (or PWM) solution - this is just a good example of what I need in terms of off-the-shelf and breadboard-ready.