Food Grade Optical Infrared Water Liquid Level Sensor 500mm Cable High Sensibility, Working with Liquid Level Controller(Pack of 3)

I was surprised at how effective these are and how easy they are to use with an Raspberry Pi Pico 2 W. I made a 3D printed cone to fit into a netcup space for hydroponics. When the water drops below the bottom of the netcup level the sensor triggers from wet to dry. Here is the CircuitPython code: # Minimum FS-IR02B Water Level Sensor Code import board import digitalio import time print("=== WATER LEVEL SENSOR - MINIMUM CODE ===") # Setup water level sensor on GP6 water_sensor = digitalio.DigitalInOut(board.GP6) water_sensor.direction = digitalio.Direction.INPUT water_sensor.pull = digitalio.Pull.UP print("Water level sensor ready on GP6") print("Hardware connections:") print("- VCC: Connect to 3V3 (Pin 36)") print("- GND: Connect to GND (Pin 38)") print("- Signal: Connect to GP6 (Pin 9)") print("") try: while True: # Read sensor (True = water present, False = no water) water_present = not water_sensor.value # Inverted logic if water_present: print("Water detected!") else: print("No water detected") time.sleep(1) # Check every second except KeyboardInterrupt: print("Stopped") except Exception as e: print("Error: " + str(e))

These work great

After a week, sensor work and not work .....

These work great, they output 5v when fully submerged which is great to trigger relay modules if you don't want to use a microcontroller.

The sensor is sealed, you don't have to worry about drilling a tank or bucket if you don't want to. You can just hot glue it on the inside of a bucket or water tank if that is what you want to do and it will be fine. *You must be certain that the type of liquid will not damage the sensor. This sensor is plastic and is NOT for solvents like gasoline or acetone!* This light based water level sensor works great. I just tried it in R/O water and it works as expected. The quality of what I've got here looks good. I am not sure what the board is supposed to be for, perhaps this also makes it a replacement for something else. On Arduino, you can just digitalRead the sensor for a HIGH or LOW value with no board or other components involved. Seems to be highly responsive to its state change. Trivial to code and implement. A great product! *For higher accuracy, use AnalogRead on the sensor (which is 5v) to get a value from around 25-1050. They read very low, under 200 or usually less when wet in R/O water and usually over 1000 out of water. I use 500 as my threshold and it works great.