# Rust ESP32 Example

An example project demonstrating integration with Rust for the ESP32-S2 and ESP32-C3 microcontrollers.

This example starts a FreeRTOS task to call a function in Rust and display the results in C.

## Setup

First, install the ESP-IDF SDK as shown in the [Get Started](https://docs.espressif.com/projects/esp-idf/en/latest/esp32/get-started/index.html) guides. For best support of the ESP32-C3, install the SDK from the master branch.

### ESP32 and ESP32-S series

To support the Xtensa instruction set, build and install custom LLVM and Rust toolchains as shown in the [Rust On Xtensa](docs/rust-on-xtensa.md) guide.

#### Podman/Docker image

Alternatively you might build the project in the container where image already contains pre-installed Rust and ESP-IDF.

Podman example with mapping multiple /dev/ttyUSB from host computer to the container:

```
podman run --device /dev/ttyUSB0 --device /dev/ttyUSB1 -it espressif/idf-rust-examples
```

Docker (does not support flashing from container):

```
docker run -it espressif/idf-rust-examples
```

Then follow instructions displayed on the screen.

### ESP32-C3

Install the RISCV target for Rust:

```sh
rustup target add riscv32i-unknown-none-elf
```

## Configure

First ensure that the environment variables for the ESP32 SDK are properly set up. If you have followed the instructions in the Getting Started guide, activate the environment with the `get_idf` alias:

```sh
get_idf
```

Next, configure the project for the desired MCU.

For the ESP32:

```sh
idf.py set-target esp32
idf.py menuconfig
```

For the ESP32-S2:

```sh
idf.py set-target esp32s2
idf.py menuconfig
```

For the ESP32-C3:

```sh
idf.py set-target esp32c3
idf.py menuconfig
```

## Build

Build the project by running:

```sh
idf.py build
```

This also runs Cargo internally, building a static library out of Rust code.

## Flash

Flash the compiled binary by running:

```sh
idf.py -p /dev/cu.SLAB_USBtoUART flash
```

## Monitor

Connect to the UART over USB port to monitor the application console:

```sh
idf.py -p /dev/cu.SLABtoUART monitor
```

To exit the monitor, press `Ctrl-]`.

## Debugging on ESP32-WROVER-KIT

```sh
openocd -f board/esp32-wrover-kit-3.3v.cfg
```