DM542T Logic Switch
I'm seeing a number of customers with the DM542T stepper driver complaining that it doesn't work with the T41U5XBB or PicoCNC. There is a simple fix for this.
The driver has a newer version out that added in a switch to select the control logic voltage between 5V and 24V. This affects the voltage that the driver expects to see on the Step, Direction and Enable signals (PUL, DIR, ENA). In addition, the default setting seems to be set to 24V, meaning it won't see 5V signals at all. I'll leave others to ponder the logic of a default setting that doesn't work with the vast majority of controllers out there. So, the simple solution is to make sure the S2 setting is for 5V.
So, just set S2 to 5V and you should be good!
In addition to the DM542T, the DM556T also comes with the same logic switch and default setting.
I'm Phil Barrett, a long time CNC enthusiast. I run a small company, Brookwood Design, that makes several breakout boards for grblHAL and love to help people get the most out of their CNC machines.