I recently purchased a LIHUIYU M3 Nano board, intending to use the PWM feature on my laser cutter. I was pleased to find that both K40 Whisperer and MeerK40t software are fully compatible with this new feature.
However, it wasn’t all smooth sailing. While using the equipment, I noticed that my Nema 17 motors were losing torque, causing missed steps. I resolved this issue by removing the 750R resistor (circled in yellow), which is part of the Vref voltage regulation circuit. Alternatively, you can replace the A4988 SENSE pin resistors with 0.22-ohm ones (circled in green).
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