Add example?

[vmasdani]

Greetings.
I was kind of having a hard time getting the grasp of trying to use the digital GPIO pin. I worked it out in the end anyway, but I think it would be cool to add basic examples as simple as LED blinking, LED breathing, etc. like this:

extern crate linux_embedded_hal as hal;

use hal::sysfs_gpio::{Pin, Direction};
use std::error::Error;
use std::thread;
use std::time::Duration;

fn main() -> Result<(), Box<dyn Error>> {
    let gpio = Pin::new(198);

    match gpio.export() {
        Ok(()) => println!("Gpio {} exported!", gpio.get_pin()),
        Err(err) => println!("Gpio {} could not be exported: {}", gpio.get_pin(), err)
    }

    gpio.set_direction(Direction::Out)?;
    gpio.set_value(1)?;
    thread::sleep(Duration::from_secs(1));
    gpio.set_value(0)?;

    Ok(())
}

[thejpster]

This seems like a good idea. Would you be able to add this as a PR to create a file in ./examples, and also note which SBC this is designed to run on / has been tested on?

[vmasdani]

This seems like a good idea. Would you be able to add this as a PR to create a file in ./examples, and also note which SBC this is designed to run on / has been tested on?

Sure, I'll make a PR later when I get my hands on the board to test it again. By the way, the SBC I tried this on was Orange Pi Zero

[vmasdani]

Hi. I'm sorry I haven't responded about this issue for a long time. I've thought about making the example + PR and I thought it would be good to make the example in gpio_cdev instead of gpio_sysfs since it is deprecated. But I tried adding the dependency in Cargo.toml like this:

[package]
name = "gpiotest"
version = "0.1.0"
authors = ["vmasdani <[email protected]>"]
edition = "2018"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
linux-embedded-hal = { version = "0.3", features = ["gpio_cdev"] }

And I got this error when building with cargo build

error: failed to select a version for `linux-embedded-hal`.
    ... required by package `gpiotest v0.1.0 (/home/valianmasdani/codes/rust/gpiotest)`
versions that meet the requirements `^0.3` are: 0.3.0

the package `gpiotest` depends on `linux-embedded-hal`, with features: `gpio_cdev` but `linux-embedded-hal` does not have these features.

Same goes when I change the feature to gpio_sysfs

the package `gpiotest` depends on `linux-embedded-hal`, with features: `gpio_sysfs` but `linux-embedded-hal` does not have these features.

When I them separately though, it's running fine and I'm able to blink an LED using set_value(value) (I still use Orange Pi Zero):

[dependencies]
linux-embedded-hal = "0.3"
gpio-cdev = "0.2.0"

It works fine, but I ended up not being able to use embedded_hal GPIO functions like is_high() or set_low().
Am I missing something here or it's actually a bug/wrong documentation?