I currently have a 36vbdc 800w motor connected to a 36v 800w motor speed controller (similar to what they use to control ebikes) just like this one: https://aws.robu.in/wp-content/uploads/2016/02/919811586_739.jpg (I don't know how to upload pics or wiring diagrams to my question or I would).
I would like to use a 2.4ghz 4ch RC remote transmitter and receiver to control the motor speed instead of the wired throttle I currently use, which is a 3pin hall sensor (+5v, Gnd, sensor) twist throttle.
Is there any way to connect the RC receiver to the motor controller to use the remote transmitter to control motor speed? How would I go about this?
I believe both the RC signal and the hall sensor are PWM, but do I need a receiver board to interface with the RC receiver and the motor controller?
Would I need to implement arduino into the equation?
Best Answer
RC servo signal is a 1-2ms pulse with repetition period of ~20ms. Ebike controllers generally accept an analog voltage between 0-5V (with 1V=off and 4V = full throttle). You will need an interface to convert from one to the other. Possible solutions range from purely mechanical (servo attached to a potentiometer) to an MCU with D/A converter.
The Arduino can measure servo pulse width with pulseIn() and produce an 'analog' output with analogWrite(). On most Arduinos the analog outputs are actually 0-100% PWM at ~490Hz. To convert this to true analog you need a low pass filter or integrator which averages the pulses, eg. this simple RC filter:-
simulate this circuit – Schematic created using CircuitLab
A side effect of integrating the PWM pulses is slower throttle response. Here is the result of simulating the above circuit in LTspice, with a 0.5 second 50% throttle burst:-