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Assignment 2: Electronics Production

This week our task is to make an in-circuit electric programmer. Actually I learned electric soldering like three years ago in a metal working practice. But at that time the thing I soldered was like 8*8 inches. So in this week the biggest challenge for me is to solder on such a small board.

Milling

The first step is to use the mill machine to make the board. Although the teaching assistant had showed us the whole process before, I still made several mistakes. I failed like four times before I got an available board. This first time there was some problem with the setting of "z" axis, the cutting depth was too deep. And then when I tried again, it seemed like the computer could not fully control the mill machine. I restarted the program and imported the image, found that one of the important procedures was to hit "open" button. One failure work is as below.

When I finally figured out and finish the traces, I got stuck with the outline. I successfully changed and adjusted the drill, but when moving to the origin, the drill was stuck. I realized that for the dill, when adjusting it manually, the part outside should not be too long. I needed to balance it and keep the outside part neither too long nor too short. Finally I got my board and prepared to solder.

11/20 Update: The jumping from the original point is that the machine would recognize the pixels in the.png file.

Soldering

The next step is soldering. The preparation included collecting all the components, make the sponge wet, and verify the directions of the components. Also I did some exercise on the waste board. Actually the process of soldering was not as hard as I imagined. Although the components and the board were very tiny, without the magnifier, I can still distinguish the cooper wires. The most difficult part was the USB, the contact was so small and I needed to work very carefully and slowly.

soldering accomplished!

Programming

My board worked and was green! Then I followed the command lines and finally I made my own programmer. When I typed "lsusb", it went well!

Since my peer's programmer has some problem with the usb recognizing. I learned how to diagnose it with the multimeter. It seemed to be tricky to diagnose a programmer, some parts may need re-soldered and maybe sometimes re-programming would help.