Arduino PAR and LUX Meters
Posted: Sun Jul 05, 2020 7:02 pm
TCS34725 PAR Sensor, Arduino Nano in enclosure and two remote sensor, USB connected to (old) notebook PC running Windows XP and Hyperterminal.
This is a Simple I2C PAR Sensor the ubiquitous TCS34725 Color Sensor for Arduino type micro-controllers or RPi.
The materials required are;
PAR Sensor: TCS34725, PVC Coupling, Acrylic Lens(es), 4-conductor shielded cable.
PAR Meter: Arduino type micro-controller, USB cable and or a Display Module.
The following are required to duplicate the sensor for accurate, reliable and repeatable measurements;
a. White Acrylic Diffuser Lens(es) with at most 15% Transparency for 0 - 2225 umol/m2/s (PPFD) range.
b. Remote sensor housings are 3/4" PVC slip coupling (Electrical) with hole sized for the 4 - conductor cable (repurposed Keyboard cable)
c. Wiring per standard TCS34725 wiring to Arduino type controllers, using 5V / Vin (for remote sensor cable lengths).
d. Parameters for Lens, Lux and PPFD (PAR) coefficient factors and Bench "Calibration" with Lux meter (or PAR meter if available).
e. Setup using "Fixed" non-adjusted Parameters... 1x - Gain, 700 ms - ATime, 2.4 ms WTIME for all sensors, no exception.
Notes;
1. The TCS34725 support documents show that Lux readings can be calibrated to 0.1% accuracy, PAR is directly related to Lux.
2. Any fixed Spectrum Grow Light with a known Lumens to PAR conversion factor (Lm/PPF_Cf) can be measured with a Lux Meter.
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edited by PeteR_1, edited 4 times in total.
The "PAR" Sensor and Arduino were calibrated with a LI-COR model LI-190R Quantum Sensor. The "Multispeq Beta" PAR sensor is also able to measure RGB (Red : Green : Blue) and LUX Values!
Par Meter Build and Test... https://www.scirp.org/journal/paperinfo ... erid=88576
Testing in Multispeq Tool... https://royalsocietypublishing.org/doi/ ... sos.160592
Production Multispeq Tool... https://prl.natsci.msu.edu/people/facul ... -m-kramer/
The MultispeQ V2 mentions an additional integral part to the PAR sensor, a "Hot Mirror" / IR Cut Filter 400 - 700nm along with the TCS34715. A readily available Light Color Sensor Model TCS34725 (costs under $8.00) has an installed IR cut Filter of 400nm to 650nm. Just received the TSC34715FN Chips which will be swapped onto the TCS34725 PCB modules, still awaiting the 400-700nm Hot Mirror IR Cut Filters which have been delayed due to Covid-19 shutdowns.
TCS34725 PCB module... https://www.aliexpress.com/item/4000454 ... 4c4dRR16vo
TSC34715 Chip... https://www.digikey.com/product-detail/ ... ND/3821076
I'm a novice at Arduino programming, have only been working with it for a few months, have lots of inexpensive spare parts from a failed attempt at an over engineered MIT MVP OpenAg "Brain Controller", was easily able to implement an Arduino Lux to PPF meter with "a Data logging" function (Com Port Reader). Uses a BH1750FV (Silicon IC chip, cost $3.00) reads relatively accurate, "calibrated" with a Benetech Lux Meter and has an appropriate PPFD conversion factor for my application, 0.015 (PPF/Lm).
BH1750... https://www.aliexpress.com/item/3301179 ... 4c4d1K5MYJ
White LED Grow Lights... https://www.biorxiv.org/content/biorxiv ... 5.full.pdf
LED Lux to PPFD Factor... https://www.biorxiv.org/content/biorxiv ... 0.full.pdf