This seems like alot of work if you just want to monitor a LED lighting up. I wanted to do something similar at my home to know when the washing machine was done. I just bought one of these photoresistor sensor relays linked below and put the sensor over the Machine Done LED onthe control panel and made sure to mask it from ambient light. Now I have a set of relay contacts that run into my processor. The sensor relay engages when it sees the light of the Machine Done light.??
For our prodiction jobs we often tie in with generators that have an auxiliary relay board that gives status of running/faults/etc. Perhaps your generator has an expansion board that can be wired in?
Photo relay: https://www.amazon.com/HiLetgo-Photoresistor-Sensor-Automatic-Control/dp/B073XL5161/ref=sr_1_7?crid=2SEZRYTG8JYYQ&dib=eyJ2IjoiMSJ9.0Vhckt3HZyLlsB06Zy7hyCS3pg-lnvrkqcO03TjsrjEzoE03ljhIW5TAyvXBGqzfeC8X8iF4U8Kb8o262-E_r3h9doIcDa1idoevnCDRqwn9fs7lKzFsb1jhvKuLG214EdSPzMsSEvc1s6uuMMvS7qa0tbuSMVKvGiOulwmas2F_-9JLuz1npy6pk79LsdGKvbFu-g2G6X00HfSGvIruVG1ypbebhstfB7uyH97nj0k.2-EKd9r5mRe9_EUH-MGlpdClNrtzv_3aJnFnLxMkb2Y&dib_tag=se&keywords=optical+sensor+relay&qid=1718108510&sprefix=optical+relay%2Caps%2C113&sr=8-7
