kopia lustrzana https://github.com/espressif/esp-idf
61 wiersze
2.3 KiB
Markdown
61 wiersze
2.3 KiB
Markdown
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# Example: C++ I2C sensor read for MPU9250
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(See the README.md file in the upper level 'examples' directory for more information about examples.)
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This example demonstrates usage of C++ exceptions in ESP-IDF. It is the C++ equivalent to the [I2C Simple Example](../../../peripherals/i2c/i2c_simple/) which is written in C.
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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.
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## How to Use This Example
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### Hardware Required
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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](https://invensense.tdk.com/wp-content/uploads/2015/02/PS-MPU-9250A-01-v1.1.pdf).
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#### Pin Assignment:
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**Note:** The following pin assignments are used by default, you can change these in the `menuconfig` .
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| | SDA | SCL |
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| ---------------- | -------------- | -------------- |
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| ESP I2C Master | I2C_MASTER_SDA | I2C_MASTER_SCL |
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| MPU9250 Sensor | SDA | SCL |
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For the actual default value of `I2C_MASTER_SDA` and `I2C_MASTER_SCL`, see `Example Configuration` in `menuconfig`.
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**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.
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### Configure the project
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```
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idf.py menuconfig
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```
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### Build and Flash
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```
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idf.py -p <PORT> flash monitor
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```
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Replace <PORT> with the name of the serial port. To exit the serial monitor, type ``Ctrl-]``.
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See the [Getting Started Guide](https://docs.espressif.com/projects/esp-idf/en/latest/get-started/index.html) for full steps to configure and use ESP-IDF to build projects.
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## Example Output
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If the sensor is read correctly:
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```bash
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I (328) i2c-simple-example: I2C initialized successfully
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I (338) i2c-simple-example: WHO_AM_I = 71
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I (338) i2c-simple-example: I2C de-initialized successfully
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```
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If something went wrong:
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```
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I2C Exception with error: ESP_FAIL (-1)
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Couldn't read sensor!
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```
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