I’d like to see the Vex motor controllers upgraded to support dynamic braking under program control. This would help prevent back-driving without requiring a full control loop to actively maintain a fixed position (see this thread for an example).
The Motor Controller 29 firmware could watch for a specific signal that isn’t a valid R/C pulse train (say, 50% duty cycle?) and enable DC braking.
It may already be electrically possible for the Cortex’s built-in 2-wire ports to do this with just a firmware upgrade, if there isn’t a lockout that prevents both halves of the H-bridge both from switching to the same rail.
In order to use this feature in software, there would have to be a new function added, since it doesn’t really fit anywhere on the -128…127 power spectrum already available.
This already exists its just not supported by any of the programming options.
we played around with it by plugging it into an Arduino and then sending a 200us single and sure enough the motors went into a “braking” mode
I think that if it was supported it would almost entirely eliminate the need for arm “reverses” and such. goes to RobotC feature request thread