Embedded Registers

WARNING: This crate is currently in experimental state, so anything may change at any time.

This crate provides a procedural macro for effortless definitions of registers in embedded device drivers. This is automatically generates functions to read/write the register over I2C and SPI, although it isn't limited to those buses. The resulting struct may trivially be extended to work with any other similar communication bus.

• Allows defintion of read-only, write-only and read-write registers
• Generates I2C and SPI read/write functions
• Registers are defined as bitfields via bondrewd.
• Only the accessed bitfield members are decoded, conserving memory and saving on CPU time.
• Supports both async and blocking operation modes

This crate was designed for the embedded-devices crate, which aims to provide modern async-capable and coherent definitions for many embedded devices.

Usage

Add this to your Cargo.toml:

[dependencies]
# You will need this to define your own bitfield-capable enums
bondrewd = { version = "0.1.14", default_features = false, features = ["derive"] }
embedded-registers = "0.9.6"

For a simple register definition example, take a look at this DeviceId register from the MCP9808 temperature sensor:

#![feature(generic_arg_infer)]

use embedded_registers::register;

#[register(address = 0b111, read)]
#[bondrewd(read_from = "msb0", default_endianness = "be", enforce_bytes = 2)]
pub struct DeviceId {
    device_id: u8,
    revision: u8,
}

You may then read the register simply by calling DeviceId::read_i2c or DeviceId::read_i2c_blocking (or similarly write to it if you specified write in the definition above):

let reg = DeviceId::read_i2c(&mut i2c, 0x24 /* i2c device address */).await?;
info!("{}", reg);
// Prints: DeviceId ([4, 0]) => DeviceIdBitfield { device_id: 4, revision: 0 }

For more information and more complex examples, please refer to the embededded-registers docs and the bondrewd docs.

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option. Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.