How I built a DIY filament dryer from an inexpensive food dehydrator for my Creality Ender 3 V2 3D printer. This houses a standard 1kg spool of filament, allows printing directly from the dryer, and improves print quality and consistency.
I’ve been playing with some very cheap, but quite good power meters made by Eastron for a few years now, in particular their compact (single-DIN) single phase Modbus meters. They are great for cheap (non-commercial) energy monitoring applications. The SDM120M variant has Modbus over RS-485 support for convenient data acquisition and integration. These aren’t the […]
Murphy’s Technology Laws! I found on an old hard drive circa 2011 🙂 You can never tell which way the train went by looking at the track. Logic is a systematic method of coming to the wrong conclusion with confidence. Technology is dominated by those who manage what they do not understand. If builders built […]
I recently had a problem with a particular Raspberry Pi and was able to rescue some files. I thought I’d document this here in case it’s useful. When powered on, I got an endless output of “mmc0: fsm 1, hsts 1” scrolling on the screen. Not good! My limited understanding of this error is that […]
Note: This post is currently just some loose notes during my R&D, and is a continuation of the Extech CO250 project. See my Extech CO250 review here. I have RS-232 details and teardown here. Open-source Java library I have a working Java library that reads all values over serial and provides statistics (minimum, maximum, average, […]
The Extech CO250 (AKA Senseair pSENSE RH) is a relatively cheap handheld air quality measurement device with decent features. It measures carbon dioxide (CO2), dry-bulb temperature, and relative humidity, and also provides calculated dew-point and wet-bulb temperatures. One interesting feature, and the subject of this post, is it’s serial communications port. It comes with a […]
The Extech CO250 is a relatively cheap handheld air quality measurement device with decent features. It measures carbon dioxide (CO2), dry-bulb temperature, and relative humidity, and also provides calculated dew-point and wet bulb temperatures. After some searching I found what seems to be the OEM device which Extech rebadges. The original device seems to be […]
I recently wrote a bash script that automates a database backups to zipped files on a Raspberry Pi. I would then periodically SSH in and transfer the backup files. This was a simple temporarily and manual solution, but I wanted a way to automate sending these files to a remote backup. I use AWS quite […]
Recently I had the need to upgrade MySQL on a Raspberry Pi running the latest standard distribution version of Jessie. I needed to use the JSON data-type as a MySQL field. My Raspberry Pi (as of April 2017) was running MySQL 5.5.52, but I needed 5.7+ for the JSON data-type. Update MySQL I’m providing these […]
In this video we take a detailed look at the SCA 300W Power Inverter and review its performance in detail! I explain what a modified sine wave inverter is and how it’s different from a pure sine wave inverter, and it best applications in the field. * This product was provided to us by Supercheap […]