By Evan Fairchild
This phase 1 proof of concept serves as a great benchmark and shows the possibilities of using maker parts to prototype applications.
This was the first PCB iteration and so there were a few routing errors that were not found in the DFM checks. Luckily, nothing proved to be show stopping; many issues could be resolved in software. The board will be iterated upon soon. There will be four screw terminal routed to one bus to make sensor replacement painless. Also, the board will be extended to accommodate a prototyping area to further its customizability. The Eagle files will be published with the next blog update.
The touch worked surprisingly well and proved to be very easy to use thanks to the CAP1188 self calibrate mode that initiates on startup. Once the ITO is set you may have to reboot the RPi a few times for the touch sensors to calibrate properly but other than that it is straightforward. The timing still needs to be improved. There is a lag (~1s) between when a touch is detected to when a command is processed. I predict the problem lies in how the commands are being queued on the server side; however, I need to investigate this further.
Collecting and publishing data was very easy. The API was useful for debugging and testing my duty cycle model, especially when i could do it remotely from 350 miles away when I was up in the Bay Area!