drive questions.

[johnm]

With Sean's controller 6-8A,  the Clutch output is available at D11 of the arduino (pin 14).

Here is the diagram of the electronic interface that Sean used with the hydraulic controller at the time.

Was just going to upload my schematic but yours is probably more appropriate.
In mine I added a attiny85 that pwms the clutch. It works but managed to modify the the motor controller to do the pwm so I bypass the attiny85.
Can upload schematic and codes if anyone is interested.

I personally consider some sort clutch holding current control a necessity.
Draws over 12 watts just to hold the clutch in. It gets crazy hot.  I'm down to about 1.5 watts to hold.
As an alternative can just put resistor and capacitor in parallel in series with the clutch. That will get down to about  4 watts, mostly dissipated by the resistor.

Pierre  you may want to just buy the new motor controller with the clutch output and rudder position. It's pretty reasonably priced.
I'm thinking of buying a new one to make my setup simpler.

John