Update and improve serial protocol

[sashacmc]

Zenoh Pico side serial protocol changes for serial reopening
ZettaScaleLabs/z-serial#9
eclipse-zenoh/zenoh#1624

Additionally, common code has been moved to a common module

[github-actions]

PR missing one of the required labels: {'internal', 'breaking-change', 'new feature', 'documentation', 'bug', 'enhancement', 'dependencies'}

[ur8us]

Hi! Tried today's main branches of zenoh and zenoh-pico on the RPI Pico2:

2024-12-11T17:14:15.867800Z DEBUG acc-0 ThreadId(12) mio_serial: opening serial port in synchronous blocking mode    
2024-12-11T17:14:15.868211Z DEBUG acc-0 ThreadId(12) mio_serial: switching /dev/ttyACM0 to asynchronous mode    
2024-12-11T17:14:15.868234Z DEBUG acc-0 ThreadId(12) mio_serial: setting VMIN = 1    
2024-12-11T17:14:15.868244Z DEBUG acc-0 ThreadId(12) mio_serial: setting O_NONBLOCK flag    
2024-12-11T17:14:23.530441Z ERROR acc-0 ThreadId(12) zenoh_link_serial::unicast: Read error on Serial link serial//dev/ttyACM0 => serial/22827996-7bf6-4434-9846-e583af8a73b8: Unexpected Init flag in message at io/zenoh-links/zenoh-link-serial/src/unicast.rs:164.
2024-12-11T17:14:23.530458Z DEBUG acc-0 ThreadId(12) zenoh_transport::unicast::establishment::accept: Read error on Serial link serial//dev/ttyACM0 => serial/22827996-7bf6-4434-9846-e583af8a73b8: Read error on Serial link serial//dev/ttyACM0 => serial/22827996-7bf6-4434-9846-e583af8a73b8: Unexpected Init flag in message at io/zenoh-links/zenoh-link-serial/src/unicast.rs:164. at io/zenoh-links/zenoh-link-serial/src/unicast.rs:167.
2024-12-11T17:14:23.646821Z DEBUG acc-0 ThreadId(12) mio_serial: opening serial port in synchronous blocking mode    
2024-12-11T17:14:23.647273Z DEBUG acc-0 ThreadId(12) mio_serial: switching /dev/ttyACM0 to asynchronous mode    

Desynchronized versions? :-(

zenoh-pico:

cmake -Bbuild -DPICO_BOARD="pico2" -DZENOH_CONFIG_CONNECT="serial/8.9#baudrate=115200" -DZENOH_CONFIG_MODE=client 

zenoh:

cargo build --release --bin zenohd  --no-default-features --features transport_tcp --features transport_serial

Run:

RUST_LOG=debug ./target/release/zenohd  -l "serial//dev/ttyACM0#baudrate=115200" -l "tcp/127.0.0.1:7447" --cfg='plugins/storage_manager/storages/demo:{key_expr:"turtle1/cmd_vel",volume:"memory"}'

[sashacmc]

RUST_LOG=debug ./target/release/zenohd  -l "serial//dev/ttyACM0#baudrate=115200" -l "tcp/127.0.0.1:7447" --cfg='plugins/storage_manager/storages/demo:{key_expr:"turtle1/cmd_vel",volume:"memory"}'

Are you sure ttyACM0 is connected to pins 8.9?
This looks more like the USB serial that is provided by the Raspberry Pi Pico and where stdout goes by default.

[ur8us]

Absolutely, pins 8.9.

I tried 115200 and 38400 at the rpi pico2 side, in both cases I get the following sequence on the serial terminal's screen when the microprocessor is restarted:

02 01 01 01 01 01 01 01 00

When both zenoh and zenoh-pico were configured for the 115200 baud, there was an error message ("Unexpected init flag").

With both configured to 38400, they were able to connect!

2024-12-11T20:35:38.992816Z DEBUG net-0 ThreadId(11) zenoh::net::runtime::orchestrator: Waiting for UDP datagram...
2024-12-11T20:35:39.093533Z DEBUG acc-0 ThreadId(12) mio_serial: opening serial port in synchronous blocking mode    
2024-12-11T20:35:39.094044Z DEBUG acc-0 ThreadId(12) mio_serial: switching /dev/ttyACM0 to asynchronous mode    
2024-12-11T20:35:39.094059Z DEBUG acc-0 ThreadId(12) mio_serial: setting VMIN = 1    
2024-12-11T20:35:39.094068Z DEBUG acc-0 ThreadId(12) mio_serial: setting O_NONBLOCK flag    
2024-12-11T20:35:42.198992Z DEBUG acc-0 ThreadId(12) zenoh_transport::unicast::manager: Will use Universal transport!
2024-12-11T20:35:42.201820Z DEBUG acc-0 ThreadId(12) zenoh::net::routing::router: New Face{2, 59}
2024-12-11T20:35:42.202057Z DEBUG acc-0 ThreadId(12) zenoh_transport::unicast::manager: New transport opened between 5f29e8c92eb273ae36ac524ffce9f73 and 59 - whatami: client, sn resolution: U32, initial sn: 159016982, qos: false, multilink: false, lowlatency: false
2024-12-11T20:35:42.202079Z DEBUG acc-0 ThreadId(12) zenoh_transport::unicast::establishment::accept: New transport link accepted from 59 to 5f29e8c92eb273ae36ac524ffce9f73: TransportLinkUnicast { link: Link { src: serial//dev/ttyACM0, dst: serial/1a5f52f7-08a4-4533-9bdb-a5a5c9936eea, mtu: 1500, is_reliable: false, is_streamed: false }, config: TransportLinkUnicastConfig { direction: Inbound, batch: BatchConfig { mtu: 1500, is_streamed: false, is_compression: false }, priorities: None, reliability: None } }
2024-12-11T20:35:42.219684Z DEBUG  rx-1 ThreadId(16) zenoh::net::routing::dispatcher::resource: Register resource demo/example/zenoh-pico-pub
2024-12-11T20:35:42.223813Z DEBUG  rx-0 ThreadId(15) zenoh::net::routing::dispatcher::interests: Face{2, 59} Declare interest 2 (demo/example/zenoh-pico-pub)

Back to 115200, error. Same 9 bytes in the serial terminal, although zenoh reports an error.

Very strange!

I will check with another hardware tomorrow.

Guys, thank you so much for making the serial channel work reliably! I really hope this will attract more people to using zenoh and zenoh-pico.

[ur8us]

Example file for the z-serial-0.3.1, rpi pico2 is at 115200.

dn@DN:~/.cargo/registry/src/index.crates.io-6f17d22bba15001f/z-serial-0.3.1$ ./target/release/examples/serial-echo /dev/ttyACM0 -s -b 115200
Arguments: Args { port: "/dev/ttyACM0", server: true, baud_rate: 115200, interval: 1.0 }
Got error: Unexpected Init flag in message received [00, 00, 00, 00, 00, 00, 00, 00]

A serial terminal program still shows

02 01 01 01 01 01 01 01 00

[ur8us]

Forget it. There must be a problem in my serial-to-USB converter based on the RP2040 debug probe.

[ur8us]

Hello!

Another microprocessor: RP2350B. Another serial connection: 0.1. Another USB-to-serial: CH340.

Only the serial port name has changed in the system to /dev/ttyUSB0. Same bad behavior at 115200 baud with both zenoh and serial-echo example. Still works at 38400. :-)

This is very strange that I do not see any debug output from the other CDC port (the one which should be used as stdout for the microcontroller).

I will give up for now.

[ur8us]

Hello,

Just ported the latest version of the zenoh-pico library to the STM32/ThreadX platform. 115200 is OK, works with zenohd like a champ!

The cases when the zenoh router is not available during the call of the _z_connect_serial, or the router goes down during the serial session, still need some polishing on the zenoh-pico side, but at least the router itself behaves quite reliably.

Thank you for your great work!