# I2C Component

- I2C Modules

| Item                                    | Board      | Chipset     | Address                                   |
| --------------------------------------- | ---------- | ----------- | ----------------------------------------- |
| 3-Axis Magnetic Electronic Compass      | GY271      | HMC5883L    | 0x1E                                      |
| 3-Axis Magnetometer Acceleration Sensor | GY-LSM303C | LSM 303C    | accelerometer : 0x1D, magnetometer : 0x1E |
| Infrared Temperature Sensor             | GY-906     | MLX90614ESF | 0x5A                                      |
| 0.91' OLED Display  (128 x 32)          | Generic    | SSD1306     | 0x3C                                      |

- Datasheet

  - [HMC5883L](https://cdn-shop.adafruit.com/datasheets/HMC5883L_3-Axis_Digital_Compass_IC.pdf)
  - [LSM303C](https://www.mouser.com/datasheet/2/389/lsm303agr-954987.pdf)
  - [MLX90614ESF](https://www.melexis.com/-/media/files/documents/datasheets/mlx90614-datasheet-melexis.pdf)

  * Schematic
    - [LSM303C](https://www.tme.eu/Document/3efb39d16e2f2e2f9f16bb5c89784b47/POLOLU-2127.pdf)
    - [Adafruit LSM303C](https://learn.adafruit.com/lsm303-accelerometer-slash-compass-breakout?view=all)

- Arduino Library

  - [GY271](.\arduino-lib\Mecha_QMC5883L)
  - [GY-906](https://github.com/adafruit/Adafruit-MLX90614-Library)
  - Adafruit [SSD-1306](https://github.com/adafruit/Adafruit_SSD1306)
    + need to change below to `LED_BUILTIN` due to conflict with esp8266 i2c (Pin4 - sda / 5 - scl)
    ```
    #define OLED_RESET     LED_BUILTIN //4
    ```

- Tutorial

  - [GY271](https://www.instructables.com/id/Tutorial-to-Interface-HMC-5833L-With-Arduino-Uno/)
  - [GY-LSM303C](https://learn.adafruit.com/lsm303-accelerometer-slash-compass-breakout/coding)
  - [GY-906](https://create.arduino.cc/projecthub/SurtrTech/contactless-temperature-sensor-mlx90614-1e7bc7)

- ESP8266

  - Software controlled
  - pin assignment defined

  ```
  C:\Users\<user>\Documents\ArduinoData\packages\esp8266\hardware\esp8266\2.7.4\variants
  ```

  - SCL / SDA pinout

| Description     | SCL           | SDA   | Remark                             |
| --------------- | ------------- | ----- | ---------------------------------- |
| Official        | MTMS (GPIO14) | GPIO2 |
| Try             | GPIO0         | GPIO2 |
| generic esp8266 | GPIO5         | GPIO4 | Wire() Default for generic esp8266 |

- The change Wire default, update begin(SDA, SCL)

```
Wire.begin(2, 0)
```

- ESP32
  - Hardware Controlled
  - Pinout

| Description | SCL    | SDA    | Remark  |
| ----------- | ------ | ------ | ------- |
| Official    | GPIO22 | GPIO21 | Default |