https://github.com/stronnag/msp-rs
Sample rust code for MSP (inav etc.)
https://github.com/stronnag/msp-rs
inav msp rust
Last synced: 6 months ago
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Sample rust code for MSP (inav etc.)
- Host: GitHub
- URL: https://github.com/stronnag/msp-rs
- Owner: stronnag
- License: mit
- Created: 2021-08-13T19:32:27.000Z (almost 4 years ago)
- Default Branch: master
- Last Pushed: 2024-04-12T14:20:07.000Z (about 1 year ago)
- Last Synced: 2024-04-12T22:15:31.282Z (about 1 year ago)
- Topics: inav, msp, rust
- Language: Rust
- Homepage:
- Size: 144 KB
- Stars: 3
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# Using rust for MSP (inav etc.)
## Introduction
In the unlikely event that you're curious about using rust to communicate with a MSP flight controller (for example [inav](https://github.com/iNavFlight/inav), betaflight, multiwii even), then here's a trivial example of rust asynchronous MSP (using a "channels" pattern).
Note that this is (still) about day 4 of the author's on/off rust adventure, it may be non-idiomatic, naive etc. PRs welcome.
## Example
Bench test FC, indoors, somewhat random GPS data.
```
$ msptest /dev/rfcomm1
Serial port: /dev/rfcomm1
Name: BenchyMcTest
API Version: 2.4
Firmware: INAV
FW Version: 3.1.0
Git revsion: b079efca
Board: WINGFC
Extant waypoints in FC: 16 of 60, valid true
Voltage: 11.9
GPS: fix 2, sats 5, lat, lon, alt 50.9***** -1.5***** -1, spd 0.33 cog 7.7 hdop 6.59
```
## Usage
```
$ msptest --help
Usage: msptest [options] [device-node]
Version: 0.10.0
Options:
-s, --slow slow mode
-1, --once Single iteration, then exit
-v, --version Show version
-h, --help print this help menu
```
On Linux / Macos / Windows / FreeBSD, if no device is given, the application will make a reasonable attempt to evince any valid serial device; e.g. with `msptest` installed on `$PATH`:
```
$ msptest
Serial port: /dev/ttyACM0
Name: BenchyMcTesty
API Version: 2.4
Firmware: INAV
FW Version: 6.0.0
Git revsion: 4bbd2fa5
Board: WINGFC
Extant waypoints in FC: 0 of 120, valid false
Uptime: 550s
Voltage: 0.00
GPS: fix 0, sats 0, lat, lon, alt 0.000000 0.000000 0, spd 0.00 cog 0 hdop 99.99
Elapsed 37.25s 2306 messages, rate 61.90/s
^C
```
^C to exit.
Note for FreeBSD, only /dev/cuaU* is recognised:
Thusly:
```
# This would be auto-discovered
# macos
msptest /dev/cu.usbmodem0x80000001
# Windows
# This would be auto-discovered
msptest.exe COM17
```
You can also use a TCP pseudo-URI (e.g. for use with the SITL):
```
msptest tcp://localhost:5767
```
and on **unix** platforms, UDP:
```
msptest udp://localhost:53285
```
## Makefile
As a short cut for `cargo` commands / options, there's a Makefile
* `make build` : Builds a release target
* `make install` : Builds a release target, installs to ~/.local/bin
* `make debug` : Builds a debug target
* `make windows` : Cross-compiles a Windows executable on sane host OS
* `make clean` : Clean
## Legacy
### MultiWii
```
$ msptest
Serial port: /dev/ttyUSB0
MSP Vers: 241, (protocol v1)
Voltage: 4.20
GPS: fix 0, sats 0, 0.000000° 0.000000° 0m, spd 0.00 cog 0
Elapsed 21.64s 1298 messages, rate 59.99/s
```
### INAV F1 Processor
Note the serial message rate. The changes since 1.7 / 1.8 (increased functionality, changing of task priorities etc.) have not improved serial I/O rates, despite much faster CPUs.
```
$ msptest /dev/ttyACM1
Serial port: /dev/ttyACM1
MSP Vers: 231, (protocol v2)
Name: BV-CC3D
API Version: 2.1
Firmware: INAV
FW Version: 1.9.254
Git revsion: e4510e11
Board: CC3D
Extant waypoints in FC: 0 of 30, valid false
Voltage: 0.00
GPS: fix 0, sats 0, 0.000000° 0.000000° 0m, spd 0.00 cog 0 hdop 0.00
Elapsed 14.31s 1427 messages, rate 99.69/s
```
## TUI Display
The example has now migrated to a TUI application:
```
MSP Test Viewer
v0.12.0 on freebsd 13.1-RELEASE x86_64
Port : /dev/cuaU0
MW Vers : ---
Name : BenchyMcTesty
API Vers: 2.4 (MSP v2)
FC : INAV
FC Vers : 6.0.0
Build : Dec 29 2022 12:38:03 (243b867d)
Board : WINGFC
WP Info : 0 of 120, valid false
Uptime : 90563s
Power : 0.0 volts, 0.11 amps
GPS : fix 0, sats 0, 0.000000° 0.000000° 0m, 0m/s 0° hdop 99.99
Arming : NavUnsafe H/WFail RCLink (0x48800)
Rate : 5587388 messages in 90358.35s (61.8/s) (unknown: 1, crc 0)
```
From 0.12.0, the rate line includes the count of unknown massages and CRC errors. The CRC count should be zero; the unknown count will vary according to version:
```
Board : MultiWii
Rate : 1934 messages in 30.9s (62.6/s) (unknown: 649, crc 0)
Board : CC3D
FC Vers : 1.9.254
Rate : 4072 messages in 40.8s (99.7/s) (unknown: 1016, crc 0)
Board : MATEKF405
FC Vers : 6.0.0
Rate : 2384 messages in 38.5s (61.9/s) (unknown: 1, crc 0)
```
* MultiWii: c. 33% unknown
* Ancient INAV: c. 25% unknown
* Modern INAV: 1 unknown
## Discussion
### Unsafe (C) serial implementation
The rust serialport crate is used device enumeration. Prior to version 0.10.0, the serialport crate was also used for I/O; since then a custom implementation is used.
This example uses an (unsafe) C language implementation for serial I/O, rather than the serialport crate (or even the better serial2 crate):
* serialport did not support RISC-V (at one time)
* serialport performance on Windows is poor (c. 25% of Linux / FreeBSD / Macos) and unreliable across multiple threads. The embedded implementation is thread safe and the Windows performance is close to that of the POSIX platforms.
* serial2 requires `Arc()` in order to use a separate reader thread. This rather upsets the current device independent implementation .
### Other
There is an [similar Golang example](https://github.com/stronnag/msp-go); you may judge which is the cleanest / simplest.
## Licence
MIT, 0BSD or similar.