Dust Automation PCB

I decided to use a 70mm x 100mm PCB for the Dust Automation System.   That should have room for the PCA9685 Servo Driver, the Nano, the 74HC4051 Analog mux, power plug, and the Sensor connectors.   I'll also make a small plywood box to contain the board, and attach it to the ceiling near the main 6" plenum.   That way it will be close to the servos and not too far from the sensors.   The question mark on the Planer sensor is because of distance to it's remote power plug.   This PCA9685 16 channel servo driver came with 90° pins on the right side and I thought it would be more secure (with 8 servo cables plugged in) to have straight pins (on bottom) on each end so I can plug it in to my pcb.    

I added a 10K pull down resistor to the Mux-Z to Nano-A7 line so when I scanned to an input with no Isensor, the Nano would see a low.   The Nano's analog inputs are very high impedance and slowly drift down when disconnected from a voltage, the 10K pull down fixes that.