PCB Fabrication – been there, done that @ The Circuit Farm. Jimbo writes…
I decided to tackle something simple for my first attempt at etching a circuit board. I wanted something with a low parts count, and that was easy to test. I decided on a voltage level shifter circuit, as it only requires a MOSFET and 2 resistors per channel, and 4 channels is generally sufficient for most digital protocols.
I spent a day learning Eagle CAD, in which I created, destroyed, and re-created the circuit about 5 times. I ended up with a very clean-looking schematic, and two separate boards (both hand-routed); one for SMT parts, and one for through-hole. Both boards are really tiny; they easily fit on a breadboard.