Introduction: RC Tx Module As USB Joystick
This instructable is about making a transmitter module that works with standard RC transmitters and acts as a USB joystick.
The module uses a Digispark dev board that acts as a USB HID. It interprets the PPM signal the transmitter sends and converts it to the axes of a joystick.
RC transmitter (in this case a Turnigy TGY 9X)
A donor Tx module for the case
Digispark development board
Step 1: The Housing
Take an old Tx module. Open it up and strip it. It provides an excelent case for the electronics.
Step 2: The Connector
The connector used to interface with the transmitter is a standard 0.1" female header. It's easiest to put the module housing in the remote and the put the header. Some hot glue will provide mechanical support.
Step 3: The Electronics
The Digispark module is mounted on a piece of perfborad. It's significantly easier if it is cut to the shape of the housing. A snug fit will provide additional mechanical support.
A test fit of the components is important before going further. In this case the USB cable has been striped with an exacto knife to make it easier to bend and fit.
Step 4: Soldering
Just plain soldering the pins to perfboard. Soldered all pins for future developments. Hence the extra space on the perfboard.
Added some extra hot glue on the cable for extra mechanical support.
The PPM pin on the transmitter is connected to pin P2 on the digispark dev board. The two GND are then connected together.
Step 5: Putting It All Together
Just put the case back together. Make sure the cable is not squeezed too tight.
Step 6: Code
The code is based on abhilash_patel's project on the Arduino project hub combined with the joystick example from Digispark.
The whole code is developed in the Arduino IDE.