Electronic Production

The goal for this week is to make an electronic puzzle, the idea is that I can draw a picture on my computer and it will randomly scramble it amongst the puzzle pieces for me. There main idea is that in each puzzle piece there will be an attiny driving each display and all of the displays will communicate to a main microcontroller (the esp32 c3 xiao)

This week while trying to make my boards I realized redesigned all of them to make them all easier to mill after lecture, after asking alot of questions to Anthony, and also fixing mistakes in the board like I assumed there was continuity with both sides of the board.

The PCBS:

The goal for this week is to make 3 PCBs. There are two PCBS in the puzzle piece and I want to make a puzzle piece. There is one PCB which contains the microcontroller which will talk to all of the separate puzzle pieces, which will send them the split up parts of the puzzle. One piece drives the PCB of the screen, one piece charges a battery for each puzzle, and the final PCB is the main controller which talks to all attiny to get their locak

This PCB has an attiny which serves two functions which is two run the OLED screen, but also to communicate to the main microcontroller but reading voltage from a voltage divider in a PCB in the main grid

Getting this board up and running was actually very easy and actually worked on the first time

After getting the OLED working on this display I was wanted work on the second PCB which would have a circuit to charge a battery when connected to the grid, as well as exposed pads on the bottom so it can connect to the main grid using pogo pins

I made a jig which was meant to align the pcb such that I could mill both sides of the PCB and have everything line up. However, the faith I put into this jig was a child's delusion. The corner of the PCB did not line up perfectly in the corner of the cutout of the board and there was some give

This lead to misalignment of the throughholes, which honestly could have been salvaged. However, there was another issue which was that I forgot to put hole size in my design rules and for some reason the default size for two of my components holes were around 31 mils and so they were not cutout and I did not realize until after I had taken them out of the mill and they had been cut down to final size (Moral of the story is look for closely at the toolpath before you run a job)

It seemed at this point in the week it seemed as though the HTMAA gods did not want to see me succeed because over the week I had Mods crash on me close to 50 times. I was trying to find a pattern in the crashes, but it seemed pretty random. Sometimes it would crash while milling, sometimes it would crash if I moved the origin too many times in a row. Sometimes it would crash while just sitting there. I was very confused and was taking hours to try and do a 10 minutes job

However, after a few days of struggle I was saved by two angels sent from heaven. Lingdong and Leo who wrote webmill which actually saved my life. This program still has not crashed on me once, and was giving me very good results.

However, because of the two sided pcb. I thought I should really just work on testing the pogo pins to communicate between the microcontroller and the attiny in the puzzle piece. So I redesigned the other two pcbs to have the bare minimum components to test out this concept.

This very simple pcb was a nice change of pace, as I got it milled in a few minutes and it worked the first try.

Sadly I end off this week with power being shorted to ground because of that copper pad on the bottom of the pcb