I guess the stupid question is how is it connected to the DX system?
Connect its 2 RC signal outputs to woodygb RC interface. And that is then your joystick! Good to go. One tiny board.
You could do the same thing using 2 tiny hobby rate gyros.
In fact 2 of these would be better as they are easy to adjust for sensitivity and are rate only. So zero or centre is already taken care of. normal RC pulse output. Because they give you your centrering spring electronically. Built in. Theres no reason that head position sensors need to cost phone numbers, this stuff is cheap and common in the hobby world.
https://www.ebay.co.uk/itm/Piezoelectri ... SwEUdaazjsI'm assuming that it would be easy to make a strap and pouch to fit it in, power from chair or depending upon how much it needs a battery. 2 axis will probably be just as easy as a joystick to configure in Wizard.
It will be powered by the tiny woodygb RC interface. Instead of connecting a RC reciever, you simply connect that board. It will require an on off switch. So you can put the thing on your head. A velcro strap or something secure. Or your chair will run away as they fall off.
I need to go talk to someone who actually understands this.
As always, knowledge is power. Learn!!!
Brakes might be a step beyond our knowledge
Lennys method may work, if a little complex. But, the brake is working
correctly. You actually have a traction problem going down. It can only come on if the wheel is stopped. So lower the deceleration time some so it slows more gently, or/and move more weight rearwards to get less weight transfer.
You are wanting the brake to NOT come on if it senses the thing is stopped. And then complain it does not work properly if you delay it! You cant really have it both ways. The other issue is that it on both wheels at once. Only one may need a brake on... So depending on terrain you will always need human correction input at slow speeds.