Turbidity Sensor Issue
Richard.Peng 2026-07-09 02:48:19 38 Views1 Replies For a recent DIY turbidity sensor project, I had some trouble with the DFRobot Gravity Analog Turbidity Sensor for Arduino where:
1. Whenever power was connected from the Arduino Nano to the Turbidity Sensor controller, the Yellow light was activated, even if nothing was detected on the actual sensor module. I have tried switching between Analog and Direct and checking for any mishaps on the sensor, but nothing has seemed to work.
2. When I connected the Analog parts of the Arduino Nano (A0, A1, A2, etc.) to the specified port on the turbidity sensor controller, it constantly read 0 Volts, but when I unplugged it or plugged it into the unspecified Analog port on the Arduino, it actually read a voltage.
Hi,
Please first check the sensor connection and switch setting.
The yellow PWR LED turning on after power is connected is normal. It only indicates that the adapter board is powered.
For analog output, please set the switch to A, connect the signal pin to Arduino A0, and make sure the sensor is powered by 5V with common GND.
In clean water, the analog output should usually be around 4.1V ±0.3V. If the Arduino analog pin shows voltage only when the sensor is unplugged, that is likely a floating input, not a valid sensor reading.
Also, the Wiki FAQ mentions that if the probe cable is connected in the wrong direction, the sensor value may not change correctly. Please check the probe cable direction and refer to the Wiki here:
https://wiki.dfrobot.com/sen0189/
Yx 
