I recently bought 4 mp6500 stepper controller boards (potentiometer control, unsoldered). Have tried to set the vref based on your very good video. The problem is that I’m seeing current values from - XXXmV to a max of about 350mV.
Since my steppers have a continuous current rating of 2A, and I have heatsinks on the ICs, I figured I’d go for a 1V vref. Am surprised to see negative mV vref values, and dont understand why the max is so far below 1V.
I have the stepper boards plugged into a CNCShield board that I’ve been using for several months, and that is plugged into an Arduino Uno running GRBL.
The stepper power is 20VDC, the arduino is 5VDC.
One additional concern/note. Initially I plugged just one of the stepper boards into the CNCShield. That is where the 350mV numbers came from. As I added additional boards, the vref numbers went dramatically lower. Namely, w/ 4 boards plugged in, they were (all 4) < 10mV max. This almost sounds like I need to invest in a new CNCShield board? Or possibly in a new 20V supply? the thing is, both of these have been working just great for months, and the CNCShield really just connects these pins with those pins…