Module lp_i2c 

Available on crate feature unstable only.

Low-power I2C driver

Overview

This is the host driver for the LP_I2C peripheral, which is primarily meant to be driven by the ULP.

The driver always sends a slave sub-register address along with the device address. This makes it incompatible with I2C devices or sensors that do not expose sub-registers, and it also means an embedded_hal::i2c::I2c implementation cannot be provided.

Configuration

The driver can be configured using the Config struct. To create a configuration, you can use the Config::default() method, and then modify the individual settings as needed, by calling with_* methods on the Config struct.

use esp_hal::i2c::lp_i2c::Config;

let config = Config::default();

You will then need to pass the configuration to LpI2c::new, and you can also change the configuration later by calling LpI2c::apply_config.

You will also need to specify the SDA and SCL pins when you create the driver instance.

use esp_hal::i2c::lp_i2c::{Config, LpI2c};
let mut i2c = LpI2c::new(
    peripherals.LP_I2C0,
    config,
    peripherals.GPIO2,
    peripherals.GPIO3,
)?;

// You can change the configuration later:
i2c.apply_config(&Config::default())?;

Usage

// The device address does not contain the `R/W` bit!
const DEVICE_ADDR: u8 = 0x77;
const DEVICE_REG: u8 = 0x01;
let write_buffer = [0xAA];
let mut read_buffer = [0u8; 22];

i2c.write(DEVICE_ADDR, DEVICE_REG, &write_buffer)?;
i2c.read(DEVICE_ADDR, DEVICE_REG, &mut read_buffer)?;

Structs

Config

I2C driver configuration

LpI2c

Low-power I2C driver

Enums

ConfigError

I2C-specific configuration errors

Error

I2C-specific transmission errors

Traits

Scl

Trait representing the LP_I2C SCL pin.

Sda

Trait representing the LP_I2C SDA pin.