Light Calibration

Overview

Light is calibrated a single vial at a time using an external light probe and data logger.

Files for calibration can be found in the calibration folder of your photo-eVOLVER DPU

Before attempting this protocol you should have completed the full photo-eVOLVER setup and smart sleeve construction.

Materials

• Light meter and probe

  1. Our light meter is the LI-COR LI-1500

  2. Our light probe is the Walz US-SQS/L omnidirectional light probe

• 3D printed calibration cap

Protocol

1. Make sure you are using the calibration conf.yml not the experiment conf.yml

   • Experiment conf.yml will have pauses that cause missing values in the light calibration.

   • See here for how to change to the calibration conf.yml

2. Get a clean glass vial and fill to 25mL with water

3. Set up probe in vial using calibration cap

4. Alter calibration_vals in calibrate_light.py

5. Start logger

   • Turn on via mini-USB power cable plug on top

   • Choose 500hz sampling rate

   • Press "START"

   • New file > Label with vial number > OK > Water probe

   • Should be changing values now

6. Run calibrate_light.py

   • python3 calibrate_light.py --ip <evolver_IP> --vial <vial_num> --lights <space_separated_list_of_lights>

   • <space_separated_list_of_lights> refers to which light types you want to calibrate (light1, light2, light3)

   • Sets eVOLVER light for that vial to each value

   • Separates values in the LI-1500 log by turning off the light

7. Press the START/STOP button to stop logging

8. Repeat calibration for each vial, moving the light probe and glass vial

   1. The vial number in the file name should increase automatically

   2. You can overwrite logger files where you mess up

9. Copy the light_cal_template folder in /dpu/calibrations/ and rename with the name of this light calibration

10. Plug logger in to the computer via USB

11. Transfer files over to folder you made

12. Run analyze_light_cal.ipynb

    1. Change the constants in the Jupyter Notebook

    2. The fit_name should reflect which light you are calibrating

    
13. Transfer your final calibration file to your experiment template folder

14. The calibration file should be named light{}_cal.txt where {} is replaced with the light number to be recognized by the eVOLVER DPU script