I'm trying to build a humanoid robot based on BLDC motors instead of steppers or servos and I'm designing my custom controller board. I'm facing this beginner problem: powerful motor de-stabilizes power supply for the controller. I will write up the project in details later, when I achieve some degree of success which can be shared, but right now I'm asking for help. Details about my design and the trouble I'm experiencing can be found here http://www.dizzy.ai/2017/12/08/interference. Any input on how to mitigate the problem will be highly appreciated!
Link provided explains problem in details. Here I will just give brief overview.
This is what I see between two ground points:
This is what I see instead of 3.3V