HomeSpan / TempSensorI2C

Streams temperature readings from an I2C Analog Devices ADT7410 to HomeKit using HomeSpan

TempSensorI2C - A HomeSpan Project

TempSensorI2C is a working example of how to use the I2C protocol to capture temperature readings from an Analog Device ADT7410 high-resolution temperature sensor and stream them to HomeKit. Built using the HomeSpan HomeKit Library, TempSensorI2C is designed to run on an ESP32 device as an Arduino sketch.

Hardware used for this project:

• An ESP32 board, such as the Adafruit HUZZAH32 – ESP32 Feather Board
• An Analog Device ADT7410 Temperature Sensor, such as the Adafruit ADT7410 Breakout Board

Overview

This simple HomeSpan sketch illustrates how the standard Arduino I2C library Wire.h can be used to capture temperature readings from an ADT7410 temperature sensor and stream them to HomeKit. The sketch:

• implements a single HomeKit Accessory containing a HomeKit TemperatureSensor Service;
• captures samples from the ADT7410 every 5 seconds;
• sends updates to HomeKit only if the temperature has changed by more than 0.5 Celsius; and
• is easily modified to accomodate up to 4 ADT7410 sensors, each with their own unique I2C address.

Connections

The connections below provide for I2C communicaiton between the ESP32 and the ADT7410 using the 7410's default address of 0x48:

ADT7410	ESP32
VIN	3V
GND	GND
SDA	SDA
SCL	SCL
A0	unused
A1	unused
INT	unused
CT	unused

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