Week 7

1. Designing the baord

For this week, I want to learn how to detect how close my hands are to the board, and I think it’s a perfect time to try out directly measuring capacitance with a simple circuit, where nothing is covered up by a sensor. I based the board design on Neil’s hello.load.RP2040 demo on the website (Demo), and added more header pins for hooking up a LCD next week. My plan is to tie this to my final project and make this a random spiking nervous mouse module, which will increase it’s firing probability when I get closer to it.

I then output the Gerbers file and convert it to .png, but made a mistake initially by didn’t include the “edge” file for the “drill” file, which resulted in a drill file with out a black edge.

When feeding this .png through the mod programs, it seems fine at first but when inspecting the tool path, you can see it’s trying to mill out every blank space. I didn’t notice this until I see Carvera spending too much time going back and forth, and I stopped the machine and decided to redo it since there’s a line waiting to use Carvera. It looks clean and nice though.

Reading closely to Cyrus’s documentation, I dropped both the edge file and the drill files together to the Gerbers to png website, and this time it generated the correct outcome, which I went through the same pipeline again and mill it again.

This time it worked out nice, and the result looks like this:

Although I have supply-time management in mind and chose to start with a less ambitious project, the supply of my time unexpectedly dropped this week and I didn’t leave enough margin.

Update: For the input device, I later on played with MPU6050 IMU to detect acceleration and angle.

2. Group Assignment

For the group assignment, we probed Jessica’s Hall-effect sensor on the board to look at the changes when a magnet is put close by with an oscilloscope. We did see a bit of things going on, but when looking it with a logic analyzer, all the readings were just 255.