Although I have got possibility to use another one, I projected this open concept RC transmitter few years ago. Design You can see at the following picture:

RC transmitter

Transmitter has one “working” (RAM), one temporary (EEPROM, which is active at start up) and 16 models memories.

Its open concept is based on free availability of any input (4 joysticks, 3 knobs, 1 switch = 8 elements totally) to any of output channel (8 channels). This means maximum of free programmable 64 linear mixers. Nothing is fixed. All functions are on Your creativity and fantasy. I tested this device with gliders, acrobats, helicopters and it works perfectly.

As addition, microcontroller is able to communicate via USART in two ways:

a) boot loader (after power up with pressed central button) for upgrading firmware of main controller or saved data reading (boot loader is derived from Microchip application note AN851).

b) proportional trainer – student function: input from external converter of student transmitter (I have got another chip – PIC16F88 inside my transmitter, which acts as converter of PPM to USART, hex code is attached in the end of post as dsc.hex). This feature works in proportional mode – it means, that this is ideal tool for learning of new RC hobbyists … .

Joysticks are replacement parts of HITEC Eclipse. I was able to buy them with trims buttons as set.

Other parts are ordinary electronic components.

I am working on documentation for this device, it will be available ASAP. In case of interest please feel free to write me.

Hex for bootloader - controller must be programmed by any of PIC programmer:

rc_tx_bl.hex

Hex for main controller - programm it by P1618QP utility of Microchip (link above):

rc_tx_main.hex

Hex for DSC (see above):

rc_tx_dsc.hex