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History

Jakob Hasse 7572f75d6b refactor (cxx)!: I2C C++ classes use strong value types now Added host-based I2C C++ unit tests BREAKING CHANGE: I2C C++ interface changes, raw values for arguments are mostly not allowed anymore.		2021-12-17 14:05:52 +08:00
..
main	refactor (cxx)!: I2C C++ classes use strong value types now	2021-12-17 14:05:52 +08:00
CMakeLists.txt	refactor (cxx): C++ I2C example now uses MPU9250 instead of MCP9808	2021-11-18 19:07:44 +08:00
README.md	refactor (cxx): C++ I2C example now uses MPU9250 instead of MCP9808	2021-11-18 19:07:44 +08:00
sdkconfig.defaults	refactor (cxx): C++ I2C example now uses MPU9250 instead of MCP9808	2021-11-18 19:07:44 +08:00

README.md

Example: C++ I2C sensor read for MPU9250

(See the README.md file in the upper level 'examples' directory for more information about examples.)

This example demonstrates usage of C++ exceptions in ESP-IDF. It is the C++ equivalent to the I2C Simple Example which is written in C.

In this example, the sdkconfig.defaults file sets the CONFIG_COMPILER_CXX_EXCEPTIONS option. This enables both compile time support (-fexceptions compiler flag) and run-time support for C++ exception handling. This is necessary for the C++ I2C API.

How to Use This Example

Hardware Required

To run this example, you should have one ESP32, ESP32-S series or ESP32-C series based development board as well as an MPU9250. MPU9250 is an inertial measurement unit, which contains an accelerometer, gyroscope as well as a magnetometer, for more information about it, you can read the datasheet of the MPU9250 sensor.

Pin Assignment:

Note: The following pin assignments are used by default, you can change these in the menuconfig .

	SDA	SCL
ESP I2C Master	I2C_MASTER_SDA	I2C_MASTER_SCL
MPU9250 Sensor	SDA	SCL

For the actual default value of I2C_MASTER_SDA and I2C_MASTER_SCL, see Example Configuration in menuconfig.

Note: There's no need to add external pull-up resistors for SDA/SCL pins, because the driver will enable the internal pull-up resistors.

Configure the project

idf.py menuconfig

Build and Flash

idf.py -p <PORT> flash monitor

Replace with the name of the serial port. To exit the serial monitor, type Ctrl-].

See the Getting Started Guide for full steps to configure and use ESP-IDF to build projects.

Example Output

If the sensor is read correctly:

I (328) i2c-simple-example: I2C initialized successfully
I (338) i2c-simple-example: WHO_AM_I = 71
I (338) i2c-simple-example: I2C de-initialized successfully

If something went wrong:

I2C Exception with error: ESP_FAIL (-1)
Couldn't read sensor!