I2C 总线概述

I2C 是一种分组交换串行通信协议，允许多个主设备连接到多个从属设备，每个连接只需使用2根电线。 它用于在短距离、板内通信中将低速外设 IC 连接到处理器和微控制器。

Pixhawk/PX4 支持：

• 连接需要比严格的串行 UART 更高数据速率的板载组件：例如测距仪。
• 与仅支持 I2C 的外围设备兼容。
• 允许多个设备连接到单个总线（有效保护端口）。 例如，LED、指南针、测距仪等。

IMUs (accelerometers/gyroscopes) should not be attached via I2C (typically the [SPI](https://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus) bus is used). The bus is not fast enough even with a single device attached to allow vibration filtering (for instance), and the performance degrades further with every additional device on the bus.

集成 I2C 设备

驱动程序还需要在 /src/drivers/ (opens new window) 中包括其设备类型（drv_*.h）的标头--例如 drv_baro.h (opens new window)。

若要在固件中包含驱动程序，必须将驱动程序添加到与要为其生成的目标相对应的 cmake 配置文件 (opens new window)：

To include a driver in firmware you must add the driver to the board-specific cmake file that corresponds to the target you want to build for. You can do this for a single driver:

drivers/sf1xx

You can also include all drivers of a particular type.

distance_sensor # all available distance sensor drivers

提示

For example, you can see/search for distance_sensor in the px4_fmu-v4_default (opens new window) configuration.

I2C 驱动程序示例

To find I2C driver examples, search for i2c.h in /src/drivers/ (opens new window).

Just a few examples are:

• drivers/sf1xx (opens new window)-i2c 驱动程序，用于 Lightware sf1xx lidar (opens new window)。
• drivers/ms5611 (opens new window)-通过 I2C（或 SPI）连接的 MS5611 和 MS6507 气压传感器的 I2C 驱动程序。
• drivers/ms5611 (opens new window) - I2C Driver for the MS5611 and MS6507 barometric pressure sensor connected via I2C (or SPI).

更多信息

• I2C (opens new window)（维基百科）
• I2C 比较审查 (opens new window)（learn.sparkfun.com）
• 驱动程序框架