I forgot to set design rule clearances in Eagle and did not realize this until I imported my trace .PNG file into mods, which showed numerous traces that would not be milled between. After returning to Eagle and setting design rules to 15.7 mils for the 1/64 in end mill, I had to make significant changes to my design. I could no longer run traces between pads of the programming header or the voltage regulator. This resulted in a handful of zero-ohm resistors being used as bridges. The CAD file for my break out board is hyperlinked to the image to the left.

Even after setting design rules, mods still refused to mill between several pads and traces due to limited clearance, so I modified the tool diameter to 13 mils to give the illusion of adequate clearance. I did not realize until after milling, but there was still one pad and trace that were not milled between, which required modification by hand post milling. I milled both of these boards on the Roland-SRM20 micro mill in the EECS lab.

My first task was programming my breakout board to receive and filter the input from my Hall Effect sensor. My code is hyperlinked to the right and sets a unitless classifier to control the signal being sent to the motherboard. The video below shows me confirming the breakout board output signal with an oscilloscope.

My second task was programming the motherboard to look at the signal coming from the breakout board to control motor operation.

The system I am simulating with my wired network includes a pump (motor in this setup) with an automatic shutoff triggered by a tank level indicator (Hall Effect sensor in this setup). Once the magnetic field sensed by the breakout board exceeds a specified threshold, it sends a digital input to the motherboard to secure the motor. In the video the oscilloscope is probing the input from the breakout board (yellow) and the motherboard's motor pin output (green).