SBOA631 August 2025 HDC1010 , HDC1080 , HDC2010 , HDC2021 , HDC2022 , HDC2080 , HDC3020 , HDC3020-Q1 , HDC3021 , HDC3021-Q1 , HDC3022 , HDC3022-Q1 , HDC3120 , HDC3120-Q1
1 Introduction
Figure 1-1 Humidity Sensor Interface
OverviewTexas Instruments offers a portfolio of humidity sensors with two main interface types: analog ratiometric and digital I2C communication. These interface types can be broken up into three groups:
- Digital I2C – Register Map
Protocol
- Communication is register-based (similar to TI's Temperature sensors).
- Measurements are triggered and read by writing to and reading from specific register addresses.
- Devices: HDC1x and HDC2x (ex. HDC1080, HDC2022)
- Digital I2C – Command-Based
Protocol
- Communication is based on command sequences.
- The host sends a command to initiate a measurement and then retrieves the result using a separate read command.
- Devices: HDC302x (for example, HDC3020, HDC3022)
- Analog Output – Ratiometric
Voltage
- Sensor outputs voltage signals proportional to temperature and humidity.
- These can be fed directly into an analog system or digitized using an external ADC.
- Device: HDC3120
Each interface type requires a different approach to reading sensor data. The following sections detail these methods and provide code examples for Arduino-enabled microcontrollers.