So, I’ve mentioned in earlier posts about arduino projects that I consider the arduino to be a prototyping platform, and a damn good one at that. Hack a day seems to think of it in similar terms. It was really Doug who got be thinking in this direction with the initial PCB design for the fridge controller project, which includes space for an Atmega CPU right on the PCB, thus eliminating the need for a relatively expensive arduino board to be permanently consumed.
So I started to wonder how hard it would be to build a simple arduino replacement board. It wouldn’t need the complicated USB hardware, as you could program the Atmega on a full arduino board before installation. It would just need a time source, perhaps a LED, and a voltage regulator.
You can see in the picture above a version I quickly whipped up on a breadboard to prove this is possible. I didn’t bother with a voltage regulator in this version, and the wires off on the right go off to a power source. This quickly turned into a PCB prototype board design, which has a voltage regulator, and exposes all of the arduino digital pins except for pin 5 (which the 16MHz crystal gets in the way of). Pin 5 could be made to happen pretty easily though…
I think this was about $10 worth of parts, including the Atmega CPU, which makes it a pretty attractive option compared with the real arduino development boards. I expect to be doing a lot of my future development on a full arduino board, and then moving the finished products off onto boards like this. I expect Matt’s door bell will be exiled to one of these soon in order to free up a board. Doug and I have talked about doing a custom PCB layout which is similar, but that is yet to happen.
The best bit of this is I am really surprised by how easy it was. I’m not a hardware person, and it took only an hour or so with a schematic to come up with a working version. I’m much pleased.