Rust Embedded HAL for Apache NuttX RTOS

This crate provides Rust Embedded HAL interfaces (GPIO, I2C, SPI and Delay) for Apache NuttX RTOS.

For sample NuttX Rust apps, see rust-i2c-nuttx and rust_test

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More about NuttX Embedded HAL...

• "Rust talks I2C on Apache NuttX RTOS"

• "Rust on Apache NuttX OS"

GPIO Output

```rust // Import Output Pin Trait use embedded_hal::digital::v2::OutputPin;

// Open /dev/gpio1 for GPIO Output let mut gpio = nuttxembeddedhal::OutputPin ::new("/dev/gpio1") .expect("open gpio failed");

// Set Chip Select to Low gpio.set_low() .expect("set gpio failed");

// Set Chip Select to High gpio.set_high() .expect("set gpio failed"); ```

(Documentation)

(Implementation)

GPIO Input

```rust // Import Input Pin Trait use embedded_hal::digital::v2::InputPin;

// Open /dev/gpio0 for GPIO Input let gpio = nuttxembeddedhal::InputPin ::new("/dev/gpio0") .expect("open gpio failed");

// True if GPIO is High let ishigh = gpio.ishigh() .expect("read gpio failed");

// True if GPIO is Low let islow = gpio.islow() .expect("read gpio failed"); ```

(Documentation)

GPIO Interrupt

Interrupt callbacks are not supported yet.

```rust // Import Input Pin Trait use embedded_hal::digital::v2::InputPin;

// Open /dev/gpio2 for GPIO Interrupt let gpio = nuttx_hal::InterruptPin ::new("/dev/gpio2"); .expect("open gpio failed");

// True if GPIO is High let ishigh = gpio.ishigh() .expect("read gpio failed");

// True if GPIO is Low let islow = gpio.islow() .expect("read gpio failed"); ```

(Documentation)

I2C

```rust // Import I2C Trait use embedded_hal::blocking::i2c;

// Open I2C Port /dev/i2c0 let mut i2c = nuttxembeddedhal::I2c::new( "/dev/i2c0", // I2C Port 400000, // I2C Frequency: 400 kHz ).expect("open failed");

// Buffer for received I2C data let mut buf = [0 ; 1];

// Read register 0xD0 from I2C Address 0x77 i2c.write_read( 0x77, // I2C Address &[0xD0], // Register ID &mut buf // Buffer to be received ).expect("read register failed");

// Print the register value println!("Register value is 0x{:02x}", buf[0]);

// Write 0xA0 to Register 0xF5 i2c.write( 0x77, // I2C Address &[0xF5, 0xA0] // Register ID and value ).expect("write register failed"); ```

(Documentation)

(Implementation)

SPI

The SPI interface requires the SPI Test Driver (/dev/spitest0) to be installed:

• SPI Test Driver

SPI settings are configured in the SPI Test Driver.

```rust // Import SPI Trait use embedded_hal::blocking::spi;

// Open SPI Bus /dev/spitest0 let mut spi = nuttxembeddedhal::Spi ::new("/dev/spitest0") .expect("open spi failed");

// Open GPIO Output /dev/gpio1 for Chip Select let mut cs = nuttxembeddedhal::OutputPin ::new("/dev/gpio1") .expect("open gpio failed");

// Set Chip Select to Low cs.set_low() .expect("cs failed");

// Transmit and receive SPI data let mut data: [ u8; 5 ] = [ 0x1d, 0x00, 0x08, 0x00, 0x00 ]; spi.transfer(&mut data) .expect("spi failed");

// Show the received SPI data for i in 0..data.len() { println!("{:02x}", data[i as usize]); }

// Set Chip Select to High cs.set_high() .expect("cs failed"); ```

(Documentation)

(Implementation)

Delay

```rust // Import Delay Trait (milliseconds) use embedded_hal::blocking::delay::DelayMs;

// Get a Delay Interface let mut delay = nuttxembeddedhal::Delay;

// Wait 500 milliseconds delay.delayms(500u32); ```

(Documentation)