Zach Cohen / How to Make (almost) Anything

Output Devices / Solid State Relay

My goal this week was to add components to the Echo Hello World board to turn it into a microcontroller for a solid state relay that I would, in turn, use to power the motor of my peristaltic pump for my concrete 3D printing system.

The redesign of the board was straightforward: I added two large pads(because I was not sure how to connect wires to the SSR); one pad went to an open pin and the other went to 5V.

I soldered the board and included two large headers to wire the SSR. I messed up some of the traces and had to add jumpers to fix the connections. Programming the board went smoothly: I included an LED blink in the code to test that it was working before hooking it up to the SSR and the motor. Ultimately, the goal was to control the motor from the button on the board to simultate controlling the motor using a limit switch in my concrete extruder. The limit switch will indicate if concrete needs to be pumped into the extruder head.

I then wired the board to the appropriate inputs on the SSR, ground to the pin and 5V to 5V. On the other side, I cut open an extension cord and connected the black cables to the inputs. I then ran 110V from the outlet through the SSR to the motor, and it worked.