electornics design

echo Hello world board with button and two leds (one to program and one for power)

This week was to make a custom echo hello world board.

Using Eagle

I started to use eagle trying to connect all things together, but with the small amount of knowledge behind this not a ideal way. I looked through previous years, and they seem to put them separately, clustering into functions. In addtion to the minimal requirements, I added a led to indicate the power, which was recommended by Palash and Jeff at the recitation. For the board design, I wanted to make it as small as possible using wires with 45 degrees and use as much crossing the register bridge below technique.

Fig1. early stages using eagle

Fig2. the schematic

Fig3. layout


I had to modify the design, since I had too much little spacing between paths and rectangle corners. I discoverd afterwards that there is the DRU testing to verify milling of the design. I did another mistake to lack clearance of the board edges.

Fig4. milling

Fig5. finished milling


Soldering was faster then expected. Except there were few places that Jeff pointed out when showing at office hours.

Fig6. list of components

Fig7. soldering attiny44

Fig8. stuffed


I went to show Jeff to ask about programming the board, but he instantly discovered that my VCC and GND where short circuited. This was because one path was too close to one pin. I chopped it using a knife. I tested to see that that power was flowing and it seem to be working.

Fig9. error

Fig10. power on!

Second round (vinyl and double sided)

I started to make another board (with the same components) to know vinyl cutting and double sided circuits. Vinyl did not look like they had full accuracy cutting tiny boards. I needed to feed a much more larger piece to make the cutting stable enough (not efficient). I did not have time to stuff.

Fig11. double sided design (a bit smaller then single side)

Fig12. lacking accuracy

Fig13. did not test yet