The user interface code was pushed to the Pi, and it appeared to work well despite some graphical slowdowns during transitions. However, downloading the Firefox web browser instead of using the preinstalled Chromium allowed for smoother effect animations.
Circuit design for stepper motor control began this week. A circuit using the A4988 Stepper Driver IC was created. Using the Raspberry Pi and the A4988 python library we were able to control the motor using the Raspberry Pi GPIO.
Assembly of the board began this week following a trip to Home Depot for materials. A large backboard is supported on long parallel legs. The dispensers and other modules will eventually be fastened to this backboard. The gantry cart was installed and tested, and appeared to work fine. Some minor redesign of the pulley bracket opposite to the stepper is required however, as it currently is only able to be screwed in on the top. Unfortunately, the group's 3D printer broke this week and it may be a few days before a replacement bracket can be made.