app-template

Quickly set up a probe-run + defmt + flip-link embedded project

Dependencies

1. flip-link:

$ cargo install \
    --git https://github.com/knurling-rs/flip-link \
    --branch main

2. The git version of probe-run:

$ cargo install \
    --git https://github.com/knurling-rs/probe-run \
    --branch main \
    --features defmt

3. cargo-generate:

$ cargo install cargo-generate

Note: You can also just clone this repository instead of using cargo-generate, but this involves additional manual adjustments. This flip-link CI patch can serve as a reference on what to do.

Setup

1. Initialize the project template

$ cargo generate \
    --git https://github.com/knurling-rs/app-template \
    --branch main \
    --name my-app

If you look into your new my-app folder, you'll find that there are a few TODOs in the files marking the properties you need to set.

Let's walk through them together now.

2. Set probe-run chip

Pick a chip from probe-run --list-chips and enter it into .cargo/config.toml.

If, for example, you have a nRF52840 Development Kit from one of our workshops, replace {{chip}} with nRF52840_xxAA.

 # .cargo/config.toml
 [target.'cfg(all(target_arch = "arm", target_os = "none"))']
-runner = "probe-run --chip {{chip}} --defmt"
+runner = "probe-run --chip nRF52840_xxAA --defmt"

3. Adjust the compilation target

In .cargo/config.toml, pick the right compilation target for your board.

 # .cargo/config.toml
 [build]
-target = "thumbv6m-none-eabi"    # Cortex-M0 and Cortex-M0+
-# target = "thumbv7m-none-eabi"    # Cortex-M3
-# target = "thumbv7em-none-eabi"   # Cortex-M4 and Cortex-M7 (no FPU)
-# target = "thumbv7em-none-eabihf" # Cortex-M4F and Cortex-M7F (with FPU)
+target = "thumbv7em-none-eabihf" # Cortex-M4F (with FPU)

4. Add a HAL as a dependency

In Cargo.toml, list the Hardware Abstraction Layer (HAL) for your board as a dependency.

For the nRF52840 you'll want to use the nrf52840-hal.

 # Cargo.toml
 [dependencies]
-# some-hal = "1.2.3"
+nrf52840-hal = "0.11.0"

5. Import your HAL

Now that you have selected a HAL fix the HAL import in src/lib.rs

 // my-app/src/lib.rs
-// use some_hal as _; // memory layout
+use nrf52840_hal as _; // memory layout

6. run!

You are now all set to cargo-run your first defmt-powered application! There are some examples in the src/bin directory.

Start by cargo run-ning my-app/src/bin/hello.rs:

$ # `rb` is an alias for `run --bin`
$ cargo rb hello
    Finished dev [optimized + debuginfo] target(s) in 0.03s
flashing program ..
DONE
resetting device
0.000000 INFO Hello, world!
(..)

$ echo $?
0

Support

app-template is part of the Knurling project, Ferrous Systems' effort at improving tooling used to develop for embedded systems.

If you think that our work is useful, consider sponsoring it via GitHub Sponsors.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)

• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be licensed as above, without any additional terms or conditions.