Trouble Tuning

[Enter-Username123]

I am so excited to finally have been able to build this and have been talking about/modifying this project for over a year now. However, I am having trouble returning values other than "1." I saw in your other response you mentioned tuning the diode relative to the beam splitter, however no matter what I do I cannot get this serial monitor to return something other than one. Is there any tips you can offer or something to help? Thank you so much in advance.