Embedded graphics 0.5.0

Version 0.5.0 is released! This is a pretty big one, focussed around ergonomics. There are new macros to make drawing and positioning primitives and text much less noisy, as well as changes to the Drawing trait to remove the explicit .into_iter() call when passing objects to it.

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XML sitemaps in React with Typescript

I maintain the Repositive website which uses React for the frontend and a server that supports server side rendering for the speed and SEO benefits of SSR. I’m currently in the process of porting it over to Typescript which is kickass, but the type checker kept borking on the XML tags used in the sitemap component. What follows is a quick “note to self” on how to fix that error. There might be much better solutions out there, but this is the one that worked for me.

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Embedded Graphics 0.4.7 and TinyBMP 0.1.0

Embedded graphics 0.4.7 has been released, along with a new sister crate, tinybmp! TinyBMP aims to parse BMP-format image data using no dynamic allocations. It targets embedded environments but can be used in any place a small BMP parser is required. Thanks to TinyBMP, Embedded Graphics now supports loading this simple image format. The header photo was made using Embedded Graphics and the SSD1331 driver in pure Rust. In this post, I’ll talk through how the BMP file is parsed in no_std environments with nom and how to get BMP images working with embedded_graphics.

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Cross compiling Rust from Linux to macOS

I’ve recently been working on a Rust project at work which requires compiling for Linux (GNU), Linux (musl - for Alpine Linux) and macOS. I use Linux Mint nearly all the time, so building for macOS targets has required asking very nicely to borrow a spare Macbook Air. This is naturally a bit crap, so I set out to find a Linux-only solution to cross compile for macOS using osxcross. A weekend of pain later, and I have the following post. Hopefully it spares you a weekend of your own pain.

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Default arguments for cooler testing

In my other post about creating properly typechecked helper functions in Typescript, I missed something out from the examples that’s present in the real code: default parameters! There’s a function, createEvent, that returns an object with a dynamically generated UUID value in it. It also includes the current timestamp. This is great from the programmer’s point of view as there’s no need to wire up these values manually, but it sucks for unit tests because the values always change! The solution is to use default parameters to keep the ergonomics of a clean public API, but still support unit testing and special cases gracefully.

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Typechecking builder functions in Typescript

I’ve been working on toasting a lot of our tech debt at Repositive recently. We use an event driven microservice architecture which has various benefits, but some drawbacks concerning what data is sent where due in part to the liberal use of any in our Typescript codebases. During my refactoring rampage, I encountered some places where event objects were missing fields or otherwise weren’t being generated properly. To this end, I set out to create a type-checked solution to this problem.

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Setting the GDB safe-path cross platform

I’ve been developing an embedded Rust app (yay!) on Windows (blegh) recently. The Rust team have put incredible effort into making Rust itself work great in Windows environments, but the tooling around it can be difficult to get working correctly. My current problem was making GDB load a .gdbinit file from the current projecting when doing xargo run. Here’s how I fixed it in .cargo/config:

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Elm: counting groups of items in a list

So. Elm. It’s been an interesting experience for me, coming from a procedural language (JS) background. The learning curve is steep, but the functional nature of Elm, along with its compile time type safety really pays off. One of the (few!) problems I’ve found as a newcomer however, is that the documentation can be really frustrating sometimes. In this post, I hope to remedy that slightly by providing a newcomer’s perspective on a little bit of data processing in Elm.

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Cloning private Github repos in Rust

Cloning a private Github repo using SSH auth in Rust has proved to be a pretty gnarly problem (for my anyway), so I thought I’d share this quick tutorial to help anyone else out that might be struggling with the same issue. I’m using git2-rs which has good interface documentation, but very few pieces of example code, so I set out to fix that somewhat with this post.

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Logging analytics events in a testable way with React and Redux

One of my main responsibilites at TotallyMoney was to take care of the in-house analytics/event logging framework. Like lots of companies, understanding what users do and how they interact with a product is to get good insight on. In this regard, people reinvent the logging wheel with various krimskrams attached, me being no exception. What I want to show in this post is how to integrate an event logging framework into a React/Redux application in a way that’s scaleable and testable. Unit testable logging is important when the rest of the business relies heavily on the events and the data in them like many companies do.

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Scraping without a scraper

In between watching the rain and emptying all the shmoo out of my air compressor (long overdue), I decided to try my hand at some impromptu scraping this weekend. Matters were complicated somewhat due to me not owning a scraping tool, but I worked with what I have to make what I think are some satisfctory results. This post will be a short log of what went down and will hopefully demonstrate that one can achieve reasonably good (i.e. flat) results without having a real scraper.

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Parsing Logentries output safely using Rust

I’m fascinated by Rust for it’s safety and speed, but also because it’s simple to write low level code in what feels like a high level language. To that end, I’ve been working on a small Rust project at TotallyMoney.com (where I work) for the last week or so to see if it’s viable for production use. It’s a simple service that polls a Logentries endpoint for JSON, parses it and saves some values in a Postgres database. It’s not a very complicated task, but I saw this as a good opportunity to try Rust in a production-ish role.

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Spindle speed control using LinuxCNC 2.7 with a Huanyang inverter

Huanyang branded VFD drives are ubiquitous on eBay and other sites like AliExpress. I bought one some time ago with a 1.5KW spindle and have been controlling the speed manually with the difficult to use control panel on the front. It is, however, possible to control the VFD from within LinuxCNC using the M3 and M5 commands (I haven’t been able to get M4, reverse rotation, working yet). What’s also neat is we can get the machine to wait for the spindle to come up to speed before moving to the next line of GCode.

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