Robuta

https://www.dfrobot.com/product-2910.html
IP67-rated PAR sensor measures 400-700nm light for crop growth & solar systems. Modbus-RTU/RS485 interface, 5-30V DC. Arduino-compatible.
modbus rtupar sensorsolar monitoringplantphotosynthesis
https://www.thethingsnetwork.org/device-repository/devices/decentlab/dl-par/
The Decentlab DL-PAR consists of a Photosynthetically Active Radiation (PAR) sensor for measuring the amount of light available for photosynthesis. It is...
photosynthetically activeradiation sensordlpardevice