N-Channel Switch

What is N-Channel Switch

N-Channel Switch is a hardware device that is very much like multiplexer that takes input from two sources and based on a select signal it outputs on of these two signals.

General Function

Domains of Application

     This is a general purpose device, so it can be used in different fields; however it was specifically designed to target RC planes. 

     In UAV planes you may need to take-off and land using your own skills not autonomously using plane computer. You can easily and instantly take control from your plan. Same need when testing your UAV you need to make sure that if something went wrong you are still able to get it back again. The idea here is that this switch is completely isolated from your complex UAV logic, so if main processor hangs due to software bug you can still access this switch and get your plan back.

Another use of this switch is when trainer a new pilot on RC Planes. You no longer need to have the same type of transmitters; you can even use your FM together with his 2.4 GHz in a master slave combination.  All you need to do is to put two receivers on that plane, connect them to the switch and you can start your training session safely.

Features and Specification

• Takes Throttle, Elevator, Rudder & Aileron input from two sources. This can be two receivers or a receiver and a UAV board.
• Use PWM signal to switch from first input to the second. You can use gear, Aux1, Aux2 …etc. to make switching.
• Two digital output ports can be used to turn lights or other devices on and off by using a control signal.
• Failsafe Switching. In case one source stops sending valid data the switch automatically switches to the other source.

Pin Assignment

Input Ports

Output Ports

Circuit Diagram

Circuit Diagram

Source Code & Hex

HEX file is here
Also Source Code is here

Controlling your RC Plane from Computer using SoundCard


Controlling your RC Plane using your PC is surprisingly easy

The main idea is that RC Transmitter generates audio signals that are carried by the Radio signals using FM or spread spectrum. The receiver decode these signals and output audio signals PMM that servo understands and moves accordingly.

This link explains every thing in good details.

However the sample is for Linux, another person who helped to develop a window version in this link


What is New ?


Well the C# code above reads from a joystick and generates an audio signal. My application is basically depends on the SoundPlay.cs but allows you to control your plane from the screen directly.

I tested it on my Spektrum DX7, and an Orange RX and it worked great.

Main Things to Remember:

1- Remember to set your voice setting to 192000 Hz in your Windows settings as in the image below.
2- Set your TX to in the Trainer menu P-Link.
3- Change Windows sound volume till DX7 detects that it is connected to another Remote.


Then you can enjoy controlling your RC

You can download source code from here

and binaries



Thanks for the guys who wrote the original linux and windows version.