I'm using this Cloudray 2-phase stepper motor driver DM422S to drive this Cloudray Nema 17 stepper motor (52Ncm 1.8A). I connected the signal ports for ENA+, DIR+ and PUL+ of the motor driver to the 3.3v pin (pin 1) on the Raspberry Pi 4 GPIO header to provide the required high signal. The motor driver accepts 3.3v signal level and everything works well. I can control the motor without any issues from my Raspberry Pi 4.
However, in this Instructable "Raspberry Pi, Python, and a TB6600 Stepper Motor Driver" the author recommends against "trying to source the " + " sides of the PUL, the DIR and the ENA signals with 3.3 VDC from the RPI.". Unfortunately, the author doesn't give further explanations.
I now wonder how safe it is to use the 3.3v pin. So far I ran the motor only for a few seconds for some simple tests. In a future project though, the motor will run longer (ca. 10 - 20 minutes).
The manual for the motor driver specifies a range of 7mA - 16mA current for the signal ports. This seems to be well below the maximum permitted current draw of 50 mA from the 3.3 V pins.