This week I built the hello RBG and array LED boards because I think I might use an array of sensors and LEDs in my final project. Milling the boards went relatively quickly this time, and they came out well. One tip, before you mill out the boards, close the fab modules GUI and log in again. For some reason, when I switched from the traces settings to the outline settings without closing fab modules first, the Modela would only cut down a couple of mm regardless of what the 3D settings said. Theodora gave me the tip of exiting the GUI and it worked.
I'm getting faster at stuffing boards but the LED array requires a lot of soldering. I think next time I'll try the two-layer board to avoid all of the 0 ohm resistors. Definitely start with the microcontroller and work from the inside out to be able to easily access all of the pads.
While programming the boards, I did run into a lot of "Double check connections" errors. This is probably the most common error I run into. According to David Mellis it usually due to a hardware error such as (1) the microcontroller is not getting power (2) the ISP cable is plugged in backwards or (3) there is a soldering problem or short on the board. I tried everything, checking for incomplete solder joints with a multimeter, and re-crimping the ribbon connectors. For the RGB board, it also turned out that the board wasn't getting enough power, but after connecting a new 9V battery it programmed and ran the .c code. For the LED array board, I was able to run the fuses code but got the same error when I immediately ran the program after. I'll keep debugging, there may be a soldering issue in the array of components.
I also modified the .c code for the RBG board, switching the pin assignments so that it mapped to the diode on the board, and changing the code so that it would cycle through a rainbow of colors.