The printers brain will be a Raspberry Pi Zero computer, with a servant Arduino in the printer head itself to provide flexible monitoring and control functions on the fly. Initial calibration and static settings will be set at system startup (using MCP23017 s to set DACs, frequency generator, etc.) so wont require resources during the printing process.

This update is for the breakout board to allow the Raspberry Pi Zero to;

• Utilise 5V logic (using x3 ̶T̶X̶B̶0̶1̶0̶8̶ ICs) - NOW USING TXS0108
• Bring the USB out to a sturdier USB-B female socket
• Integrate x2 EasyDriver stepper boards, with selectable 5V / 24V feed to allow use with L298N driver for larger current motors.
• Provide a ribbon cable connection for x15 logic lines and power (24v required for the polygon mirror motor) to the printer head

The following Eagle CAD layout of the breakout board, shows the rPiZero and EasyDriver units with the x3 voltage level converters.

3D CAD model to check assembly below. POGO pins used to connect out the USB from the test pads on the underside of the rPiZero. nylon stand-offs will be used to secure the boards.