Ben Waber.How to Make Almost Anything.Input Devices

For this assignment I wanted to make a weight sensor, but it seems like I wasn't able to get good enough resolution so I ended up making a button. Soldering has gotten easier for me, but apparently milling the PCB has not. I used the Modela, but like a lot of people I forgot to run the Modela a second time to cut my board out of the blank piece of copper. Here's the lines you need to uncomment:

# uncomment next two lines to mill out board
#cad.function = pcb.interior
#z = -.065

After putting together the board I was all set to go, but first I had to solder two copper plates to a cable to use as an input. This seems easy enough, but initially I tried to connect the two plates to pins 1 and 3. This didn't work, but using pins 1 and 4 worked great and gave me the appropriate response. Here's a picture of the final product:

Then I went into the code and used Tkinter's image library so I could toggle between two images using the copper plates (sandwiched around a piece of foam) as a button. The idea would be for my final project to detect whether or not a baby was on the changing table. Unfortunately by default Tkinter can only import GIFs, although there are some ways to get around it. Still, the icons that I used were GIF quality so it was easy to import. After changing Neil's program (here's my code), here's the default (no one touching the copper) screen:

And here's the picture when the baby is on the table:

I'm still going to try to get the weight sensor function to work, but I'll probably have to change the methodology since the current method just doesn't have the resoltion to distinguish weight at the 500 gram level.