HIH-4030 Humidity Sensor Hookup Guide

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The SparkFun HIH-4030 Humidity Sensor Breakout measures relative humidity (%RH) from Honeywell’s HIH-4030 humidity sensor. The breakout allows you to connect the analog output of the sensor directly to an ADC on a microcontroller.

SparkFun Humidity Sensor Breakout - HIH-4030


Voltage applied to the supply pins should be within 4-5.8 VDC, and optimally at 5V. The sensor will typically only consume about 200μA.

This tutorial serves as a introduction to the HIH-4030 and the SparkFun Humidity Sensor Breakout. It covers both the hardware and firmware requirements of the breakout to start receiving relative humidity (%RH) measurements as well as documenting example wiring, Arduino code and using the sensor in conjunction with a thermometer.

As we step through the Hookup Guide, you’ll find it useful to have the HIH-4030 Datasheet on hand.

HIH-4030 Datasheet

Required Materials

To get the humidity sensor up and running, you’ll need the following parts. Further in the tutorial, you’ll learn how to incorporate a temperature sensor, specifically SparkFun’s Digital Temperature Sensor Breakout - TMP-102, for properly determining relative humidity (%RH). Note that adding a temperature sensor is optional, but its use will be highlighted in this tutorial.

Suggested Reading

Before getting started with the HIH-4030, you should ensure you are familiar with the following topics:

Voltage, Current, Resistance, and Ohm's Law

Learn about Ohm's Law, one of the most fundamental equations in all electrical engineering.

Analog to Digital Conversion

The world is analog. Use analog to digital conversion to help digital devices interpret the world.

Logic Levels

Learn the difference between 3.3V and 5V devices and logic levels.

Analog vs. Digital

This tutorial covers the concept of analog and digital signals, as they relate to electronics.