Week 3 : Electronics Production
My First Circuit Board
The assignment this week was to make the FabISP in-circuit programmer.
I’ve never dealt with electronics before, so I was a bit intimidated with this assignment.
I Decided to work very slowly, step by step, to make sure I understand and do everything correctly.
I followed this great tutorial which was very helpful.
The first time, after I finished stuffing the board with all components, I got an error saying I should double check connection and try again. After triple checking all connections and soldering with the help of Thras, our TA, we got to a conclusion that there is probably something wrong with the attiny44 chip, and it would be best if I just make a new board from scratch.
I think this was a great decision. The second board took me less then half of the time to make, it came out prettier and worked perfectly. And also, most imporantly, I feel much more confident about my soldering skills now.
Making the board:
The first step is milling the board.
This is pretty simple. I just had to load the settings, that were already on the computer in the shop, to the fab modules. I used a new mill head so I changed the speed to 3.7 mm/s and the cut depth to 0.12 mm.
On my second board I changed the number of offsets to -1 in order cut everything but the traces, this took about 6 minutes more for milling, but preffer it since I think it looks cleaner, and is easier to debug that way.
After milling comes the hard part - soldering.
Testing and Programming The Board
The last step is connecting the board to the computer an program it to be a programmer.
As mentioned, in my first attempt, this did not go well. I get blinking orange light on the ATAVRISP2 Programmer, which means something is wrong with my connections.
At the second attempt this went great. I got green light on my first try. After programming my programmer I removed the jumpers, and - voilà!