Hi -
I've owned a used GPD-3303S power supply for several years and have never been happy with the rotary encoders and what appeared to be contact bounce issues. Quickly setting the voltages/currents seems troublesome and frustrating. I discovered that the problem is not de-bouncing issues (at least in my case) but the algorithm used to implement the encoder acceleration. When tuning the encoder quickly, the value would increase so rapidly that I would typically overshoot the value. Very annoying in my opinion, so the goal was to eliminate this annoyance.
To my knowledge, V2.11 is the latest firmware version for this supply. If others have a more recent version I would be interested in getting a copy. In any event I took on the task of reverse engineering the acceleration algorithm firmware and want to share my results. The attached file is a new version of V2.11 that can be loaded using the Microchip Boot loader per the user manual. I modified the algorithm such that a quick turn of the encoder will increment the display by either 1V/1A (Course) or 10mV/10mA (Fine). A slow turn of the knob retains the 0.1V/0.1A (Course)/1mV/1mA (Fine). In addition, a fast turn will zero out the 100mV/100mA (right 2 digits). I find this modified firmware much more user friendly.
I've also attached a copy of the V2.11 firmware in case you need/want to revert back to the original firmware. If anyone has any other ideas I would be interested in hearing from you.
Thanks
Jim
![GPD-3303S Encoder Acceleration Firmware - New Version 1384183-0](https://www.eevblog.com/forum/index.php?action=dlattach;topic=308383.0;attach=1384186;image)