Using Hobby Radio to provide input to microcontroller

Wireless & IoT
1

I’ve been digging around for a few days now trying to find a good way to input “servo” commands from a hobby radio receiver into a microcontroller.

I want to then have the microcontroller interpret the 3 channels of input from the radio and drive several servos in a coordinated manner.

I have found several circuit boards that allow the control of PM electric motors, but none that control servos.

There has to be a relatively simple way to do this, and I’m at a loss as to why I can’t “just find it”.

Any insight would be greatly appreciated.

2

several boards that take RS232 and produce signals for servos.

More commonly, the microprocessor creates servo signals using timers and PWM built-in. Very common.

Less common: that micro measures input pulse widths as you say from an R/C receiver and creates a 0-100% integer for each. Then does some logic. I’ve seen this done using common microprocessors’ ability to measure pulse widths.

3

Yes, I have found all the common boards (like the Bot Board 2 from Lynxmotion or the various parallax offerings) that have an RS232 bus and can drive upwards of 20 servos.

So, what do people do that want to control a robot over a distance greater than IR can provide? Coming from the RC hobby, it surprises me this isn’t a common thing to do…

4

What microcontroler are planning to use?

I have signals from two channels accepted and acted upon using a Picaxe28X1. The transmitter is a Futaba FAAST 2.4GHz. My application is to ignite a glow plug depending on the position of the Throttle channel. The second signal is used to adjust the trigger point.

5

I have not yet selected a controller for the project. I have a Spektrum DX3R system that I’d like to interface with.

Does your system use the PIC only for the purpose of reading the two inputs and then broadcast the information to another controller, or are you able to run the whole system with it alone?

6

The PIC is connected to the Radio Control receiver. It reads the pulse width and acts accordingly.

For example if the pulse is =< than 100 then set an output pin high. If the output pin is connected to the gate of a MOSFET then current will flow through it and it will ignite the glow plug.

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