Hello TI,
I have been evaluating the DRV8711 for a while using the DRV8711EVM and Eval PCB. I've also designed it into my application, and FW is already being developed.
I've noticed a really annoying bug, or perhaps I'm using the EVM software wrong... I'm very familiar with TI's App Note regarding Stepper Trajectory algorithms.
The Motor Control SW lets you adjust the following for trajectory profile:
Starting Speed (PPS)
Target Speed (PPS)
Accel Rate (PPSPS)
#steps to move
Steps to Stop
Stopping Speed (PPS)
I've found empirically that only #Steps, Steps to Stop, and Stopping Speed affect motion when moving a specific # of steps using the "Move Steps" button.
"Steps to Stop" affects the "acceleration rate", and "Stopping Speed" affects the max speed.
However the acceleration change is only applied to the RAMP-UP profile, and not the RAMP-DOWN. The end of trajectory is a hard-stop regardless when the #steps has been reached.
In my application, we are moving back and forth between certain positions; so end positional accuracy is more important.
Is there a quick workaround for this? (I will have our own custom FW in a few weeks, but until then I'm using the EVM SW for prototyping).
