During the off season, we are working on our drive station, and part of that is improving our operator interface. We’re moving from an eStop CCI joystick interface to the LaunchPad so we can get some indicators to echo control state back to the operator. (we do this with the dashboard too, but we’d like indicators close to the physical controls).
Given the number of GPIOs on the LaunchPad, there aren’t enough for all the controls+indicators we’d like, so we’ve been playing around with the LaunchPad firmware. The plan is to use 3 pins to shift out all the indicator bits via something like a MAX6969 and use the rest of the pins as button inputs.
The default firmware on the LaunchPad only supports 16b for indicators, so we’ve expanded that to 32b to match what the control system seems to be passing. However we can’t get the control software to pass more that 24b. When we set the output descriptor to 8b, 16b, or 24b it works and we get clean data all the way through. But when we expand it to 32b, the control system seems to pass no data.
We can live with 24b worth of indicators, but we’d like to understand where the limitation is, if for no other reason than to make sure we aren’t doing something that will bite us in the future (reliability issues, fragile to control system updates, etc).
Anybody else developed custom LaunchPad firmware?