Exercise 4

We used Eagle to redisign board and added a USB plug for easier programming. Also the form factor was designed to be similar to USB sticks. A LPKF ProtoMat S62 PCB Mill was used to to create the board for the FabISP programmer. CircuitCAM PCB is the software to further process the boards data to give precise instructions to the software BoardMaster like path, milling bit per task. The ProtoMat S62 has automatic tool changer with 10 standard tools. One of them is the Universal Cutter 0.2mm for milling the outlines of the circuit paths. The 1.0 mm for milling the larger areas. Then there are two contour router with 1.0 and 2.0 mm to cut out the board. Most of the time we choose the 2 mm contour router because it is more roboust. Then a bunch of spiral drills for the holes in different sizes (0.6 - 1.0 mm) and an end mill with 1.0 mm. The speed of the tools is between 30,000 and 50,000 rpm and it is highly recommended not to change that. Detailed description on how to use this machine can be found here. All components soldered are in the list below. After that I used a galvanization kit with a gold electrolyte to coat the USP plug to prevent it from oxidation. The eagle files can be downloaded here. I then used an Arduino Uno as ISP programmer (upload the Arduino ISP scetch). I connected the pins 10, 11, 12, and 13 (reset, mosi, miso, sck) to the corresponding pins of the atiny. It is important to use a condensator between reset and ground to prevent the arduino from resetting while programming. Finally I used AVRDUDE to upload the FapISP firmware via the Arduino Bootloader.