HTS221 I2C Driver Implementation for the ESP32

An I2C driver for the HTS221 Humidity Sensor used on the Raspberry Pi Sense-HAT boards.

This implementation is for connecting the HTS221 on the Sense-HAT board to an ESP-32-C3 microcontroller.

The pins used were as follows:

---

GPIO0 => SDA

GPIO1 => SCL

GND => GND

3V3 => 3v3

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NOTE: The 5v pins were not used as the temperature, pressure, humidity, accelerometer, and magnetometer sensors did not use 3v.

The GPIO/I2C pin configuration can be found in hts221_i2c_main.c

All I2C registers are documented in hts221_i2c.h

Requirements

1. ESP32 (I specifically tested the ESP32-C3 board. For other ESP32 boards, YMMV)
2. ESP-IDF with your favorite code editor/IDE (I used the current master. YMMV on older versions)
3. Raspberry Pi Sense-HAT (YMMV on other boards using the HTS221)
4. No-solder breadboard
5. Male-to-Male Wires

Build/Flash/Monitor

The following snippets assume that you have already setup the ESP-IDF, opened a terminal/command prompt that has the ESP-IDF environment variables set, and configured the project to use the ESP32-C3. <ESP32 PORT> is a device that looks like /dev/ttyUSB0 in Linux, /dev/cu.0 in MacOS, and COM0 in Windows.

To build the project without flashing the ESP32:

$ idf.py build

To build the project and flash the ESP32:

$ idf.py -p <ESP32 PORT> flash

To see the serial output on the board at a later point:

$ idf.py -p <ESP32 PORT> monitor

To build, flash, and monitor the program's serial output on the ESP32:

$ idf.py -p <ESP32 PORT> flash monitor

For more information, please visit the ESP-IDF's Getting Started page.