I am in progress of rebuilding my Bristol trawler (to a russian pr. 574 trawler in about 1/30), and also in progress of building Mountfleet models Sealight. Both are planned to have lots of functions. As I only have a 10 ch FS-i6 RC, and want to keep costs down, I decided to design and build a "board computer" myself.
Goal: As many additional data channels (switch or proportional) as possible, out to the longest range. Preferrably with telemetry data.
At first, sender. I decided to use Arduino Mega 2560 as a sender computer. It will be housed as additional box screwed to my sender's handle. 16 analog inputs will be used by 6 mini joysticks and 4 potentiometers. (or 5 joysticks/6potentiometers). Also, several 3-position switches and push buttons would be there. I would use an I2C display for telemetry display. For communication, I will be using HC-12 433Mhz protocol. With range of around 1500 meters outdoors, it is more then enough. As the data would be non-critical (boom movement, projector servo, sound, anchor), 9600 baud would probably be enough (I could use higher rate but at cost of range). HC-12 would be driven by hardware serial interface.
On the receiver side:
I am going to use Orange Pi Zero and a few Arduino Pro Mini. A very small quadcore Cortex A7 1.2 Ghz processor with 256 Mb memory, most likely with Armbian running. In idle it takes around 250 mah, comparable with my FPV camera. Internal communication is over I2C.
Pro Mini 1 - interacting with IBUS from my receiver. Sending regular channel data to Pi, feeding telemetry into Flysky system. Probably controlling powerloads over MOSFETs. Such power loads are bilge pump, fan for selfmade smoke generator, etc.
Pro Mini 2+ or PCA9685 - Servo controller for acting servos.
OrangePi - main thing. It shares following:
- Sound operation. Different horns, speed-proportional sounds, background sound, radio effect, morse transmissions...
- HC-12 communication, data aggregation of RC and HC-12 data, actuating PCA9685s.
- XML based config for all actions