Target side implementation of the RTT (Real-Time Transfer) I/O protocol. RTT implements input and output via a debug probe using in-memory ring buffers and polling. This enables debug logging from the microcontroller with minimal delays and no blocking, making it usable even in real-time applications where e.g. semihosting delays cannot be tolerated.

While this crate is platform agnostic, some platform-specific code is needed for locking if you want to use the global rprintln! macro.

If using Cortex-M, there is built-in support with a feature flag:

# Cargo.toml
rtt-target = { version = "x.y.z", features = ["cortex-m"] }

Otherwise, check the documentation for the set_print_channel_cs function.

Output directly to a channel object with write! or the binary write method does not require locking and therefore does not need any platform-specific code.

With a platform support feature, printing is as simple as:

use rtt_target::{rtt_init_print, rprintln};

fn main() {
    rtt_init_print!();
    loop {
        rprintln!("Hello, world!");
    }
}

To run the examples you will have to provide any needed platform specific configuration such as .cargo/config or memory.x yourself. Additionally you must specify a feature to enable the example dependencies, such as --feature examples-cortex-m.