Gravity: Non-contact Digital Liquid Level Sensor

Q: What is the sensor working principle?

Its working principle is to use the water sensing capacitor to detect whether liquid is present. In the absence of liquid near the sensor, there will be a presence of distributed capacitance, and therefore there are some certain static capacitance to ground on the sensor. When the liquid level slowly increases close to the sensor, the parasitic capacitance of the liquid will be coupled to the static capacitance so that the final capacitance value of the sensor becomes larger and the changed capacitance signal is then input to the control IC for signal conversion,. Then converting the changed capacitance into the amount of change in the electrical signal. Lastly, by using a certain algorithm to detect and judge the degree of this chang we can determine when the amount of change exceeds a certain threshold that means the liquid level to reach the induction point.

1. Example Code for Arduino-Get Liquid Level

This example is to get liquid level. (Liquid Level Sensor-XKC-Y25-T12V)

Reference

Specification

Parameter	Value
Operating Voltage (InVCC)	DC 5 ~ 24 V
Current consumption	5 mA
Output voltage (high level)	InVCC
Output voltage (low level)	0V
Output current	1 ~ 50 mA
Response time	500 ms
Operating Temperature	0 ~ 105 ℃
Range for thickness of induction (sensitivity)	0 ~ 13 mm
Humidity	5% ~ 100%
Material	ABS
Waterproof performance	IP67
Dimension	28 * 28 mm / 1.1 * 1.1 inches

Pinout

Version Notes

Old Version (V1.0) Package: Y25-T12V V1.0 adapter board + Y25-T12V sensor.
New Version (V2.0) Package: Y25-T12V V1.0 adapter board + Y25-V sensor. Due to changes in the sensitivity adjustment method, the ADJ button function on the Y25-T12V V1.0 adapter board has been removed; sensitivity is now adjusted via the knob on the back of the Y25-V sensor. For detailed adjustment instructions, please refer to the Y25-V Sensitivity Adjustment Method section below.

Y25-T12V Sensor Pin Definitions

Label	Name	Function Description
1 (Brown)	VCC	Positive power supply terminal; range: +5V to +24V
2 (Yellow)	OUT	Liquid level signal output
3 (Blue)	GND	Negative power supply terminal
4 (Black)	ADJ	Sensitivity adjustment port

Y25-V Sensor Pin Definitions

Label	Name	Function Description
1 (Brown)	VCC	Positive power supply terminal; range: +5V to +24V
2 (Yellow)	OUT	Liquid level signal output
3 (Blue)	GND	Negative power supply terminal
4 (Black)	ADJ	N/A

Y25-T12V Adapter Board Pin Definitions

Label	Name	Function Description
Left 1	VCC	Positive power supply terminal
Left 2	IN	Liquid level signal input
Left 3	GND	Negative power supply terminal
Left 4	ADJ	Sensitivity adjustment port; press the "SET" button to toggle the sensor's sensitivity. The number of flashes from the sensor's indicator light indicates the sensitivity level. Each click changes the setting; there are 4 levels in total, cycling through them.
Right 1	OUT	Liquid level signal output
Right 2	VCC	Positive power supply
Right 3	GND	Negative power supply

Y25-V Sensitivity Adjustment Instructions

If the liquid level is not detected or there is a discrepancy between the detected level and the sensor, open the sensor's rear cover and use a small screwdriver to adjust the sensitivity knob.

Turn counter-clockwise to increase sensitivity.
Turn clockwise to decrease sensitivity.