Capacitive moisture sensor - analog and I2C, 3.3-5.5 V

Product overview

• Capacitive humidity sensor with analog and digital output interfaces
• Measuring range from 0 to 100 percent relative humidity
• Analog output from 0 to 3.3 volts for direct level readings
• I2C interface for serial data transmission with multiple sensors on one bus
• Operating voltage from 3.3 to 5.5 volts, with voltage regulator for a wide input voltage range
• Calibration-free operation with factory-calibrated readings
• Small SMD design for space-saving integration into circuits

Product description

A capacitive humidity sensor with dual interfaces measures relative humidity and provides the readings in two ways. The analog output supplies voltages between zero and 3.3 volts and is suitable for direct readout by analog-to-digital converters; the I2C bus, on the other hand, enables multiple sensors to operate on one line, significantly reducing the number of required connection pins.

The sensing element uses the change in capacitance as humidity increases. Factory calibration eliminates the need for adjustment, allowing the module to operate immediately after connection without calibration. Operating voltages between 3.3 and 5.5 volts are handled by the integrated regulator, enabling use with various power supply configurations.

Typical applications include climate monitoring in storage or living areas, with measurement resolution across the full range from zero to 100 percent relative humidity, as well as soil moisture measurements in horticulture or agriculture. Where a fast response to humidity changes is required, such as in drying processes or material moisture monitoring, the two outputs prevent delays caused by protocol overhead.

For operation via the analog output, a microcontroller with an A/D converter and three connections is sufficient; for I2C use, only a two-wire data connection is required in addition to the power supply. Level shifting for 5-volt logic on the data line is required only when operating with a sensor supply voltage of 3.3 volts; it is not needed when the sensor is supplied with 5 volts.

Safety notice

The sensor is not intended for installation in household mains circuits and is exclusively designed for building prototypes and for testing and development purposes. Work on or near electrical installations must be carried out by qualified electricians; if you are unsure about the correct level shifting or operating voltage, consult a qualified electrician before commissioning.

Scope of delivery

• Humidity sensor
• Breakout board