[esp] Add Rust no-std example.

esp/rust/02_esp-idf-no-std/.cargo/config.toml

@@ -0,0 +1,16 @@
+[build]
+target = "xtensa-esp32-espidf"
+
+[target.xtensa-esp32-espidf]
+linker = "ldproxy"
+runner = "espflash flash --monitor"
+rustflags = [ "--cfg",  "espidf_time64"]
+
+[unstable]
+build-std = ["std", "panic_abort"]
+
+[env]
+MCU="esp32"
+# Note: this variable is not used by the pio builder (`cargo build --features pio`)
+ESP_IDF_VERSION = "v5.2.3"
+

esp/rust/02_esp-idf-no-std/.github/workflows/rust_ci.yml

@@ -0,0 +1,42 @@
+name: Continuous Integration
+
+on:
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - "**/README.md"
+  pull_request:
+  workflow_dispatch:
+
+env:
+  CARGO_TERM_COLOR: always
+  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+jobs:
+  rust-checks:
+    name: Rust Checks
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        action:
+          - command: build
+            args: --release
+          - command: fmt
+            args: --all -- --check --color always
+          - command: clippy
+            args: --all-targets --all-features --workspace -- -D warnings
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Setup Rust
+        uses: esp-rs/xtensa-toolchain@v1.6
+        with:
+          default: true
+          buildtargets: esp32
+          ldproxy: true
+      - name: Enable caching
+        uses: Swatinem/rust-cache@v2
+      - name: Run command
+        run: cargo ${{ matrix.action.command }} ${{ matrix.action.args }}

esp/rust/02_esp-idf-no-std/.gitignore

@@ -0,0 +1,4 @@
+/.vscode
+/.embuild
+/target
+/Cargo.lock

esp/rust/02_esp-idf-no-std/Cargo.toml

@@ -0,0 +1,49 @@
+[package]
+name = "esp-idf-no-std"
+version = "0.1.0"
+authors = ["Shaun Reed <shaunrd0@gmail.com>"]
+edition = "2021"
+resolver = "2"
+rust-version = "1.77"
+
+[[bin]]
+name = "esp-idf-no-std"
+harness = false # do not use the built in cargo test harness -> resolve rust-analyzer errors
+
+[profile.release]
+opt-level = "s"
+
+[profile.dev]
+debug = true    # Symbols are nice and they don't increase the size on Flash
+opt-level = "z"
+
+[features]
+default = []
+
+experimental = ["esp-idf-svc/experimental"]
+
+[dependencies]
+log = "0.4"
+esp-idf-svc = "0.51"
+esp-idf-hal = "0.45.2"
+anyhow = "1.0.98"
+
+# --- Optional Embassy Integration ---
+# esp-idf-svc = { version = "0.51", features = ["critical-section", "embassy-time-driver", "embassy-sync"] }
+
+# If you enable embassy-time-driver, you MUST also add one of:
+
+# a) Standalone Embassy libs ( embassy-time, embassy-sync etc) with a foreign async runtime:
+# embassy-time = { version = "0.4.0", features = ["generic-queue-8"] } # NOTE: any generic-queue variant will work
+
+# b) With embassy-executor:
+# embassy-executor = { version = "0.7", features = ["executor-thread", "arch-std"] }
+
+# NOTE: if you use embassy-time with embassy-executor you don't need the generic-queue-8 feature
+
+# --- Temporary workaround for embassy-executor < 0.8 ---
+# esp-idf-svc = { version = "0.51", features = ["embassy-time-driver", "embassy-sync"] }
+# critical-section = { version = "1.1", features = ["std"], default-features = false }
+
+[build-dependencies]
+embuild = "0.33"

esp/rust/02_esp-idf-no-std/build.rs

@@ -0,0 +1,3 @@
+fn main() {
+    embuild::espidf::sysenv::output();
+}

esp/rust/02_esp-idf-no-std/rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "esp"

esp/rust/02_esp-idf-no-std/sdkconfig.defaults

@@ -0,0 +1,10 @@
+# Rust often needs a bit of an extra main task stack size compared to C (the default is 3K)
+CONFIG_ESP_MAIN_TASK_STACK_SIZE=8000
+
+# Use this to set FreeRTOS kernel tick frequency to 1000 Hz (100 Hz by default).
+# This allows to use 1 ms granularity for thread sleeps (10 ms by default).
+#CONFIG_FREERTOS_HZ=1000
+
+# Workaround for https://github.com/espressif/esp-idf/issues/7631
+#CONFIG_MBEDTLS_CERTIFICATE_BUNDLE=n
+#CONFIG_MBEDTLS_CERTIFICATE_BUNDLE_DEFAULT_FULL=n

esp/rust/02_esp-idf-no-std/src/main.rs

@@ -0,0 +1,62 @@
+use esp_idf_hal::delay::{FreeRtos, BLOCK};
+use esp_idf_hal::i2c::*;
+use esp_idf_hal::peripherals::Peripherals;
+use esp_idf_hal::prelude::*;
+
+const SSD1306_ADDRESS: u8 = 0x3c;
+
+fn main() -> anyhow::Result<()> {
+  esp_idf_hal::sys::link_patches();
+
+  let peripherals = Peripherals::take()?;
+  let i2c = peripherals.i2c0;
+  let sda = peripherals.pins.gpio21;
+  let scl = peripherals.pins.gpio22;
+
+  println!("Starting I2C SSD1306 test");
+
+  let config = I2cConfig::new().baudrate(100.kHz().into());
+  let mut i2c = I2cDriver::new(i2c, sda, scl, &config)?;
+
+  // initialze the display - don't worry about the meaning of these bytes - it's specific to SSD1306
+  i2c.write(SSD1306_ADDRESS, &[0, 0xae], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xd4], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0x80], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xa8], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0x3f], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xd3], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0x00], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0x40], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0x8d], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0x14], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xa1], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xc8], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xda], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0x12], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0x81], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xcf], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xf1], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xdb], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0x40], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xa4], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xa6], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0xaf], BLOCK)?;
+  i2c.write(SSD1306_ADDRESS, &[0, 0x20, 0x00], BLOCK)?;
+
+  // fill the display
+  for _ in 0..64 {
+    let data: [u8; 17] = [
+      0x40, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+      0xff, 0xff, 0xff,
+    ];
+    i2c.write(SSD1306_ADDRESS, &data, BLOCK)?;
+  }
+
+  loop {
+    // we are sleeping here to make sure the watchdog isn't triggered
+    FreeRtos::delay_ms(500);
+    i2c.write(SSD1306_ADDRESS, &[0, 0xa6], BLOCK)?;
+    FreeRtos::delay_ms(500);
+    i2c.write(SSD1306_ADDRESS, &[0, 0xa7], BLOCK)?;
+  }
+}

esp/rust/README.md

@@ -3,6 +3,7 @@
 ```bash
 shaunrd0/klips/esp/rust
 ├── 01_es-idf-std   # Template project for using ESP-IDF with std enabled.
+├── 02_es-idf-no-std   # Template project for ESP-IDF using no std.
 └── README.md
 ```