PCU

polarization-controller-Unit

Repository for all the final files of the polarization controller project completed by Sean Bommer.

The polarization controller unit (PCU) is a modular laser cut device that is capable of rotating 2 1-inch polarizing waveplates. it operates using an Arduino Nano and two DRV8834 stepper motor drivers, found at the folowing link. https://www.pololu.com/product/2134 which control 2 28BYJ-48 5V Stepper Motors. the construction is made up from 3mm acrylic and M3 bolts and nuts.

The PCU can be powered from the 5V line of the Arduino Nano, which allowing for the whole system to be run from the USB port of a PC. The OS for the device is contained in the Arduino IDE code in this repository, two versions are available:

The 'position' version sets the start location (it's position when switched on) as position = 0 Degrees and then rotates the waveplate to the target orientation with respect to this 0 position. For example, upon start up the device is asked to rotate to 90 degrees. the device turns to this position. it is then asked to turn to 90 degrees again. the device does not move, as it is already at 90 degrees.

The 'distance' version reads the degrees input as how far it should rotate. For example, upon start up the device is asked to rotate 90 degrees. the device turns this distance. it is then asked to turn 90 degrees again. the device will turn another 90 degrees, thus being 180 degrees from it's origin point.

This device is designed to be very modular, and complies to the dimensions required for the Thorlabs cage mount system. the waveplates are controlled independently of each other so it can operate with either one or 2 waveplates.

When attached to the base mount via the M3 screws the, the whole system can be mounted to an optical breadboard via the 2 slots either side of the base and up to 4 L-shaped mounting brackets. In this configuration, with two waveplates setup, the PCU can serve as a mounting point for a simple optical cage setup as well.

FOLDERS:

    The Arduino folder contains the position and distance versions of the OS which are compatible with the arduino Nano.
    it also contains the autostep testscript, that can be used to check if all components work without serial communication and also 
    measure any motor drift the system has when used in conjunction with the Matlab findMotorDrift.m file.
    
    The Matlab folder has the findMotorDrift.m file which can be used to measure the motor drift of the system whn used with the
    autostep arduino script.
    
    The LabVIEW folder holds a simple Serial Interface with the PCU allowing simple click and go operation of the PCU

    The PCB folder has all the Kicad files needed for the design of the PCU PCB on a one-sided copper plate.

    the Fusion 360 contains the design files for the laser cut acrylic parts of the PCU.