Here's
version 2. And
here, if that first link doesn't work for you.
Subtle differences: the full "square" of the stick movement is now enabled for the "crab" mode. That means you get 100% power
only at full deflection, which would make for more accurate handling.
And in "steer" mode, I've toned down the steering at full ahead and full reverse - you get 20% "throw" when at full speed, compared to 100% when slow. This means less
shopping trolley when motoring about, but full
pirouette when stationary or at slow speed.
The thing is, once the basics are done, tweaking the specific constants in the programming allows for all sorts of mixer rates to best suit the vessel/operator/conditions.
As to
transferring to electrical wizardry: an on-board microprocessor takes PWM inputs from the receiver. It crunches the info using a program
*. It outputs PWM signals to the ESCs and four servos.
A board like the Arduino (~£30) can handle the PWM inputs and outputs with a huge amount of accuracy and a high clock speed: you get a simple "single stick and switch" input which maximises all the functions of a twin VS on the boat, without having to master octopus-like levels of stick-control.
*programs need programmers. But programs are simply recipes written in a machine-friendly language. The examples I posted use a language called ActionScript, and took well under an hour to produce. I'm currently learning how to program the Arduino, and would be delighted to offer a hand when A/ I've mastered it, and B/ you're ready to go sail-by-wire.
Andy