FreeLSS Electronics Board

thingiverse

This is a small Raspberry Pi 'shield' for controlling a FreeLSS based 3D scanner. The board measures just 42x52mm, mounts directly onto the Raspberry Pi GPIO port, and features an onboard buck converter module that powers both the stepper driver (Pololu-style DRV8825 or DRV8832) and the Raspberry Pi itself. All you need is a single 12-24V plug pack to get started. I have received enough interest in the PCB's to order a second batch. If you're interested in getting one, send me a message! Assembly is relatively straightforward; all components are clearly marked on the board. However, keep in mind that the two MosFETs require some attention: check the pinout of the part you're using and ensure it's inserted correctly - for example, the VN10LP has pins arranged differently than those outlined on the board. Before attaching the board to the Raspberry Pi, be sure to adjust your DC-DC converter to set your 5V output between 4.9-5.1V. It's been pointed out that using an A4988 stepper driver module can be unreliable when supplied with a 5V power source and 3V3 logic signals. This is because the minimum logic high voltage required is 0.7*VDD or 3.5V, which may not work on some boards using 3V3 logic. I've personally used an A4988 driver at home without issues, but I can't guarantee it will function in all cases.