18 Dec 2019

Eastron SDM120 power meter Modbus configuration

Eastron SDM120 Title

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 […]

23 Mar 2018

Extech CO250 Protocol Details

Extech CO250 Protocol Title

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, […]

22 Mar 2018

Extech CO250 RS-232 details

Extech CO250 Title

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 […]

21 Mar 2018

Extech CO250 Review

Extech CO250 Kit 2

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 […]

10 Oct 2016

SCA 300W Power Inverter

SCA 300W Power Inverter Review

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 […]

18 Jul 2016

Pico 228 LED Video Light Review & Teardown

Pico 228 LED Video Light

In this video I review and teardown a compact and very bright video and photography light. I have an upcoming video that shows colour temperature and brightness measurements and my overhead lighting configuration. *This is an unpaid, non-sponsored review* Further information eBay product page Workbench shelving video I reference (YouTube)  

6 Jun 2016

SCA Automatic Car Battery Charger Review & Teardown

SCA Automatic Car Battery Charger

In this video I review an automatic car battery charger and measure how affective it’s 7 stage charge cycle is but monitoring it’s voltage and current. *This is an unpaid, non-sponsored review* Here’s another video where I do a quick teardown of the charger to see how it’s built and the quality of its components. […]

25 May 2016

Facit NTK Mechanical Calculator, 1957

Facit NTK

In this video we look at the Facit NTK Mechanical Calculator from 1957! In this video we answer some questions from the last Facit NTK Mechanical Calculator video. I explain how the decimal place markers work and what happens when you divide by zero! Further information John Wolff’s excellent website User manual (PDF) I refer […]