As a project idea for a young engineer we wanted to build a Raspberry Pi-based Weather Station . Our last attempt at building something – a sound-responsive LED display – was a failure. So it was important to build something really easy to help us get back on track. Here are some notes. We essentially followed this guide from Adafruit which links out to this guide for the CircuitPython part.

I read about aesthetic uses of Latin Squares on John Cook’s site a few months ago. Since I maintain a resource to use colour tables in Igor Pro, I thought it would be fun to use Latin Squares to display colour tables for easy visualisation. Briefly, I wrote some code to generate a 9 x 9 latin square and assigned the values 1 – 9 to a colour table wave. The results were nice.

Generating movie files for publication can be a bit tricky. We have a protocol for making them for microscopy data, which simplifies things. However, we recently got this question from a journal: How can we do this? What information is needed for movie files?

I run two pi-holes on my home network (details here). The older of the two was in need of a refresh. Here are some notes on how I did a reinstall. For those that don’t know, a pi-hole is a simple ad-blocking solution. You can donate to the project here. Problem The pi-hole itself can be easily updated over ssh using pihole -up however the OS also needs occasional updating for security.

Here is a quick method for checking parity between two directories. Let’s say we have two directories dir1 and dir2. They are large and have thousands of files and subdirectories. How can we check that they have the same contents? I found myself in this situation recently during a server migration.

Quantifying the degree of colocalisation of two signals in microscopy images is very tricky. Lots has been written on this topic, including in my book The Digital Cell. The focus of this post is on visualising colocalisation . One way to look at colocalisation is two think about two sets of objects and how many of each set overlap. This is sometimes referred to as co-occupancy or object-based colocalisation .

In a previous post, I described a coding challenge sent to me by my colleague. Here is the challenge again: My solution was… let’s say… over-engineered. He did tell me that the winner (the challenge was set in an international coding competition) solved it in a ridiculously short time. He didn’t tell me how short which I think would have led me to take a different approach.

A colleague sent me a coding challenge. This is a short post to describe how I tackled it. Edit: a follow-up post is here. This is the challenge: With an eye on b, and since I code fastest in Igor, I went with Igor over python or R. I knew this would lose me major points for c since Igor code is not very compact. It took me 22 minutes to write a solution, slowed down a bit by helping a small person with their homework.

A quick tech tip. I usually use Audacity for converting audio files and I have a few simple macros set up in there to make life easy. I had some opus music files which do not play in Apple’s Music app and therefore needed converting to MP3 format. Annoyingly, Audacity 3.1.2 on macOS does not currently import opus files, so I needed to find an alternative. The command line tool ffmpeg can be used to convert audio files. So how can we do it?

Back in 2015, I wrote a guide to using Trello for lab organisation. I figured it was time for an update because a few things have changed since then and the topic of using Trello for larger labs came up on Twitter. Note that other kanban-style software is available. Basic Trello setup I set up a lab workspace and invited everyone in the team to it. We have three main boards (described below) that everyone in the workspace can see.