Category: Programming

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Programming

Creating a Prometheus metrics exporter for a 4G router

Grafana view of some of the reception metrics
Grafana view of some of the reception metrics

Recently I begun fully remote working from home, with the main network connectivity provided by a 4G mobile router. Very soon I experienced patchy connectivity, not the greatest thing when you are on video calls for half of each day. What does one do then (if not just straight replacing the whole setup with a wired ISP, if possible), other than monitor what’s going on and try to debug the issues?

The router I have is a less-common variety, an Alcatel Linkhub HH441 (can’t even properly link to on the manufacturer’s site, just on online retail stores). At least as it should, it does have a web front-end, that one can poke around in, and gather metrics from – of course in an automatic way.

The Alcatel HH41 LinkHub router that I had at hand to use

Looking at the router’s web interface, and checking the network activity through the browsers’ network monitor (Firefox, Chrome), the frontend’s API calls showed up, so I could collect a few that requested different things like radio receiving metrics, bandwidth usage, uptime, and so on… From here we are off to the races setting up our monitoring infrastructure, along these pretty standard lines:

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Programming

How not to start with machine learning

I’m a technical and scientific person. I’ve done some online courses on machine learning, read enough articles about different machine learning projects, I go through the discussions of those projects on Hacker News, and kept a bunch of ideas what would be cool for the machines to actually learn. I’m in the right place to actually do some project, right? Right? 🚨 Wrong, the Universe says no…

This is the story of how I’ve tried one particular project that seemed easy enough, but leading me to go back a few (a bunch of) steps, and rethink my whole approach.

I bet almost everyone in tech (and a lot of people beyond) heard of AlphaGo, Deepmind’s program to play the game of Go beyond what humans can do. That has evolved, and the current state of the art is Alpha Zero, which takes the approach of starting from scratch, just the rules of the game, and applying self-play, can master games like Go to an even higher level than the previous programmatic champion after relatively brief training (and beating AlphaGo and it’s successor AlphaGo Zero), but also apply to other games (such as chess and shogi). AlphaZero’s self-learning (and unsupervised learning in general) fascinates me, and I was excited to see that someone published their open source AlphaZero implementation: alpha-zero-general. That project applies a smaller version of AlphaZero to a number of games, such as Othello, Tic-tac-toe, Connect4, Gobang. My plan was to learn by adding some features and training some models for some of the games (learn by doing). That sounds much easier to say than to do, and unravelled pretty quickly (but probably not as quickly as it should have been).

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Maker Programming

Home Automation Mix-and-Match

This week I got a Wio Link prototype from a friend at Seeed Studio. It is an ESP8266-based little Internet of Things board with 6 Grove connectors for easy device connectivity, wifi networking, and controlled over an app & the Internet. For a quick project I wanted to hook it up with Home Assistant, an open source home automation platform that I read a lot about lately. The main focus was to have a first impression of both parts, and build up some experience for future, more serious projects.

The target solution: light up an LED if a particular person is at home location. Sort of a basic alarm system, though notice that the location of the LED was not mentioned – it can actually be anywhere in the world, as long as there’s Internet connectivity.

I’ve used the Wio Link, a Grove LED light, an Olimex OLinuXino Lime2 board running ArchLinux for the server, and a Buffalo router with DD-WRT system installed.

Wio Link

Wio Link was introduced in Seeed’s Kickstarter campaign, where they have raised more than 8x of their original target. It looks like a neat little board, and was happy to try out when I got my hands on one.

Their wiki page has quite a bit of information, so it was easy to get started. Connect to power, hold down the configure button till the LED lights up in a “breathing” pattern, connect through their Wio Link app, set up the wireless network settings and so on. Once connected, can define what kind of devices are attached to the board, and it looks like most of Grove devices are represented there. I only had a Grove LED at hand, so added it (“Generic Digital Output”), updated it, which created a new firmware and pushed onto the device.

Wio Link setup process (left to right): add device, update firmware, check status
Wio Link setup process (left to right): add device, update firmware, check status

The first update took a couple of minutes, but it’s pretty straightforward. The device then also has an API link, which brings up a web page with all the options to query, control, and reset the attached accessories (in my case that’s the one digital output).

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Maker Programming

Scratch Your Robot Itch

Recently I’ve been experimenting with the Scratch programming language, created by the Lifelong Kindergarten Group at MIT. It’s a fun environment that uses visual programming: drag-and-drop pieces of code blocks, and control objects on a stage, and the stage itself. It has quite a bit more depth to it, than the expression “visual programming language” implies, with it’s internal messaging system, multitasking, and event-driven approach. While it was originally aimed at creating interactive graphics and animations (see this TEDx talk by Prof. Mitch Resnick on the background), it is now evolving into new territories with the Scratch Experimental Extensions.

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Programming

Language of the Month: Rust, the results

Every now and then I do a “Language of the Month” feature when I spend one month to learn a new programming language. This last month in November I’ve spent with Rust, and it’s time to take stock. Will look at the impression I had in this short time, show one project that I get done in Rust, and some ideas what I’d like to do with Rust in the future!

Experience

According to my time log, I have spent about 20 hours this month learning Rust. That’s way too little to have a good understanding, but definitely enough to have some educated guesses (and excitement, and horror , as appropriate). This time I’m generally very impressed as Rust comes across as indeed a very modern and smart language, although that modernness is mostly in the tooling and non-essential parts. It is also changing very quickly, for good and bad. Here are some, admittedly subjective and incomplete list of observations. Good is what I like, Bad what’s less nice IMHO, and Ugly is what’s imperfect or confusing (at this stage of my Rust learning):

Good

It’s great to see that documentation is a not an afterthought, but a core part, that is making use a lot of modern development experience. Having a standard way to include example code in docstrings and actual tests are run on them to make sure the examples are also up-to-date with the code is a very cool concept. Also being able to auto-generate HTML documentation from the code is probably going to be standard in most new languages (I think Go does that also, and other languages have gained similar optional tools)

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