Homemade Hardware - Week 3 + 4: Interactive Marquee Letter E
Andy gave this schematic to us and it doesn't need any change. A takeaway here is:
LEDs in series will have different brightness, so it's better to make a parallel circuit.
Making an "E" shape PCB board is not easy. So I hand drew the design draft to arrange LEDs and calculated the coordinate of each point.
This board design took me almost 2 hours to finish with the help of Carlie and Karly. (Two [kalis] lol)
We together figured out how to avoid jumper wire(I can't remember the term...).
The tip here is, downsize the unit of the grid, so you can have the free control of your parts. Or it will snap to the grip, which was very annoying.
Problem: I can't find the align and distribute functions of Eagle.
The sensor circuit is not that hard. I use my photocell to replace the potentiometer.
THE MILLING PROCESS
I break my 1/32 bit, from which I learned a lesson:
1. Make sure the contour lines have tape beneath it, or the board may bump out when it is being cut off and may break bits
2. Add maybe 0.1 to 0.2mm for the tape and any unevenness
I had a very good time making these PCBs.