Earlier in the year I needed to build a control system with the capability to detect alcohol vapour, measure fluid temperature, sound audio alarms and trigger relays. I designed a circuit board for the Atmega 328 chip and soldered all the components on to produce the finished item. It took quite a while to to this, and, whilst testing circuits on a breadboard was ok, I could really have saved myself a lot of bother if I had had a PCB that could be adapted to my needs, rather than creating a whole new one from scratch. So, after the project had finished, I thought what would I have liked to have been able to buy to have produced that project and what would I like to have to produce future projects, without the time and expense of getting batches of custom made PCBs made for the specific purpose. This was when the idea of a flexible, hackable, multi-functional PCB came to mind.
Step 1: My previous board
My previous board, although it worked well, would be a nightmare to hack as it's really small and compact and the tracks are not well organised. It had a K-type thermocouple circuit in the middle, an audio amplifier in the top right and a 4 x 20 LCD screen in the top left, which covered much of the board. One of the main hassles was constantly having to pull out the Atmega chip and slot it into an Uno for making pragramming changes.
Step 2: Methalyzer project
The finished product was a bit more presentable. Note the USB slots in the foreground for attaching sensors.