Saturday, February 15, 2014

Smell of Red: Solenoid Circuit

My good friend Nathaniel Stern asked me for help with creating a circuit to drive solenoids for a new project he is working on.  We decided to fab some PCBs that will utilize a ATTINY microcontrollers and MOSFET transistors to drive solenoids. Above is the toner image (which I designed in Fritzing) printed on toner transfer paper.

Transfered toner resist onto blank PCB, fresh out of the acid.

Resist removed.

Cut and drilled.


Video demo of the working circuit (I used an old 5v/1a cellphone charger for a test power supply.)

I also made Nathaniel a shield for easily programming the microcontroller, using an Arduino UNO as an ISP.  I designed this for myself last summer, and he liked it enough to ask for one for himself.  Happy to help, buddy!


  1. Thanks, dude; you rock. You were also great on Saturday at the Startup event. This stuff will be featured in Brooklyn, this May / June, FYI :)

  2. ...great fabrication documentation, I use ATtiny85 for paper circuit programming and still have as yet to make my own PCB from scratch. I notice your use of a 5 volt regulator, which protects the tiny so you can use higher power sources. I like your clean design and am thinking of how I could mod it for soft circuits.