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56 lines
2.7 KiB
Markdown
56 lines
2.7 KiB
Markdown
| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C5 | ESP32-C6 | ESP32-C61 | ESP32-H2 | ESP32-P4 | ESP32-S2 | ESP32-S3 |
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| ----------------- | ----- | -------- | -------- | -------- | -------- | --------- | -------- | -------- | -------- | -------- |
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# HAL I2C test
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This code demonstrates how to use hal functions to write an I2C master driver.
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Note: This test is a pure hal i2c test. It CANNOT work with i2c driver in `esp_driver_i2c`.
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## Overview
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This test demonstrates basic usage of HAL (Hardware Abstract Layer) functions to write a simplest I2C master driver. This driver only relies on the I2C, GPIO and XTAL hardware features. Therefore, it can work on a bare metal environment, without any interrupt or memory allocation support. This example shows:
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1. How to write an I2C driver for bare metal applications, such as in a bootloader.
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2. How to use IDF HAL functions if you want to use the hardware I2C component to any 3rd party system or application.
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Restricted by source we can use, this test focuses on the usage of hal functions instead of providing perfect APIs. You can arrange better APIs based on your application usage.
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## How to use test
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### Hardware Required
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To run this test, you should have one ESP32, ESP32-S, ESP32-C, ESP32-P or ESP32-H based development board, call functions you can see the correct result. If possible, you can also see wave on logic analyzer or oscilloscope.
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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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| DEVICE1 | SDA | SCL |
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| DEVICEn | SDA | SCL |
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For the actual default value of `I2C_MASTER_SDA` and `I2C_MASTER_SCL` see `test Configuration` in `menuconfig`.
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**Note:** There's no need to add an external pull-up resistors for SDA/SCL pin, because the driver will enable the internal pull-up resistors.
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### Build and Flash
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Enter `idf.py -p PORT flash monitor` to build, flash and monitor the project.
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(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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## test Output
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```bash
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I (300) hal_i2c_main: HAL I2C initialized successfully
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I (320) hal_i2c_main: HAL I2C write-read successfully
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```
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## Troubleshooting
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(For any technical queries, please open an [issue](https://github.com/espressif/esp-idf/issues) on GitHub. We will get back to you as soon as possible.)
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