# rtt-target
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.
## Platform support
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:
```toml
# 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.
## Usage
With a platform support feature, printing is as simple as:
```rust
use rtt_target::{rtt_init_print, rprintln};
fn main() {
rtt_init_print!();
loop {
rprintln!("Hello, world!");
}
}
```
## Running the examples
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`.