Want to run a grblHAL based CNC machine without spending much money? Then the PicoBOB is for you.
Based around the extraordinarily inexpensive (yet highly capable) Raspberry Pi Pico, the PicoBOB costs barely more than the generic “Mach3 BOB” it’s designed to work with.
What does Expatria Technologies have to say about it?
The PicoBOB allows you to use the high performance GRBLHAL motion control system with a traditional Mach3/LinuxCNC parallel-port breakout board. It is intended to be simple and low cost. It uses a Raspberry Pi Pico RP2040 MCU module and the widely available 5 axis Mach3 breakout board.
The PicoBOB closely tracks the features of the Mach3 BOB:
- Up to 5 axes of step/direction control.
- 10A Spindle relay control.
- 0-10V analog spindle speed control.
- 5 general purpose inputs
- One general purpose output.
Communication with GRBLHAL on the PicoBOB is accomplished via the USB connection on the Pi Pico. The short USB cable shown in pictures is to provide the required 5V for the BOB. In addition, the BOB requires an external 12-24V supply.
The Mach3 BOB shares the B axis direction signal with a spindle relay enable signal – only one can be used at a time. Also on the PicoBOB, the stepper enable signal is modified in the GRBLHAL default map file so that it is used as the coolant output signal. All of this is configurable by re-building the GRBLHAL firwmare.