Releasing rust_gpiozero v0.2.0

A new version packed with new features and improvements

 Posted on February 27, 2019  |  2 minutes  |  Rahul Thakoor

For the past month I have been working on rust_gpiozero. This new release is a complete rewrite and uses Rene van der Meer(@golemparts)’s [rppal](https://github.com/golemparts/rppal) crate under the hood. It also uses Rust 2018 edition.

Why rppal?

Simply because Rene has done an incredible work on rppal. It provides first class support for the Raspberry Pis. Instead of trying to (poorly) reimplement the features, I think it is best to build upon the rppal. More importantly, Rene just added support for embedded-hal drivers which is going to make adding more components to rust_gpiozero much easier by leveraging already existing drivers. You should definitely check out rppal.

What’s new?

The main goal for this release was to provide software-based PWM components. At first I experimented with wiring_pi. Fortunately, Rene added softpwm in [rppal](https://github.com/golemparts/rppal/releases/tag/0.11.0) v0.11.0 after I requested which made implementing the following components a breeze:

  • Adding speed feature for Motor component
  • PWMOutputDevice
  • PWMLED
  • Servo

There are some API changes in existing components. Also, the blinking or beeping methods now run in a background thread and do not block the main thread by default.

Learning Journey

I started rust_gpiozero as an educational project and this release was very instructive:

  • I worked with threads in Rust which helped me better understand the borrowing, thread safety and closures. I worked with std::sync::Arcand std::sync::Mutex. However, I think there is still more to learn and discover.
  • I used macro_rules! for the first time. While previously using traits, I felt not being able to override functions and also have access to struct data implementing the traits a challenge. With macro_rules!, I organised common implementations accordingly and implemented them where needed. It also made the code “DRYer”.
  • I got a better understanding of Pulse Width Modulation
  • I formatted the code with rustfmt and clippy ❤️

What’s next?

I am going to write some tutorials on how to use the new features and components. I will also update Physical Computing with Rust to use the new version of rust_gpiozero.

I hope to release more new features soon. You can also test the new version and provide feedback.

rust  raspberry pi  physical computing