uf-crsf

A no_std Rust library for parsing the TBS Crossfire protocol, designed for embedded environments without an allocator.

This library provides a two-layer API:

• A low-level layer for raw packet parsing from a byte stream.
• A higher-level layer that converts raw packets into idiomatic Rust structs.

Features

• no_std and allocator-free for embedded systems.
• Two-layer API for flexible parsing.
• Supports a wide range of CRSF packets.
• IO and MCU agnostic.
• Minimal dependencies.

Implementation status

Legend:

• 🟢 - Implemented
• 🔴 - Not Implemented

Packet Name	Packet Address	Status
Broadcast Frames
GPS	0x02	🟢
GPS Time	0x03	🟢
GPS Extended	0x06	🟢
Variometer Sensor	0x07	🟢
Battery Sensor	0x08	🟢
Barometric Altitude & Vertical Speed	0x09	🟢
Airspeed	0x0A	🟢
Heartbeat	0x0B	🟢
RPM	0x0C	🟢
TEMP	0x0D	🟢
Voltages	0x0E	🟢
Discontinued	0x0F	🟢
VTX Telemetry	0x10	🟢
Link Statistics	0x14	🟢
RC Channels Packed Payload	0x16	🟢
Subset RC Channels Packed	0x17	🔴
RC Channels Packed 11-bits	0x18	🔴
Link Statistics RX	0x1C	🟢
Link Statistics TX	0x1D	🟢
Attitude	0x1E	🟢
MAVLink FC	0x1F	🟢
Flight Mode	0x21	🟢
ESP_NOW Messages	0x22	🟢
Extended Frames
Parameter Ping Devices	0x28	🟢
Parameter Device Information	0x29	🟢
Parameter Settings (Entry)	0x2B	🔴
Parameter Settings (Read)	0x2C	🔴
Parameter Value (Write)	0x2D	🔴
Direct Commands	0x32	🟢
Logging	0x34	🟢
Remote Related Frames	0x3A	🟢
Game	0x3C	🟢
KISSFC Reserved	0x78 - 0x79	🔴
MSP Request	0x7A	🔴
MSP Response	0x7B	🔴
ArduPilot Legacy Reserved	0x7F	🔴
ArduPilot Reserved Passthrough Frame	0x80	🟢
mLRS Reserved	0x81, 0x82	🔴
CRSF MAVLink Envelope	0xAA	🟢
CRSF MAVLink System Status Sensor	0xAC	🔴

Note

Library is under active development and testing, API might change at any time.

Installation

Add uf-crsf to your Cargo.toml:

[dependencies]
uf-crsf = "0.1.0"

Or use the command line:

cargo add uf-crsf

Usage

Here is a basic example of how to parse a CRSF packet from a byte array:

use uf_crsf::CrsfParser;

fn main() {
    let mut parser = CrsfParser::new();

    // A sample CRSF packet payload for RC channels
    let buf: [u8; 26] = [
        0xC8, // Address
        0x18, // Length
        0x16, // Type (RC Channels)
        0x03, 0x1F, 0x58, 0xC0, 0x07, 0x16, 0xB0, 0x80, 0x05, 0x2C, 0x60, 0x01, 0x0B, 0xF8, 0xC0,
        0x07, 0x00, 0x00, 0x00, 0x00, 0x00, 252,  // Packet
        0x42, // Crc
    ];

    for item in parser.iter_packets(&buf) {
        match item {
            Ok(p) => println!("{:?}", p),
            Err(e) => eprintln!("Error parsing packet: {:?}", e),
        }
    }
}

License

This project is licensed under the Apache 2.0. See the LICENSE file for details.

Protocol Specification

• Official TBS CRSF Protocol Specification
• CRSF Working Group Fork