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 support for convenient data acquisition and integration. There aren’t the easiest things […]

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 […]

18 Apr 2016

Sanden PET-07 Power Supply RS-232 Module Reverse Engineering – Part 2

Sanden Title 2

In this video we take another look at the RS-232 plug-in module for the Sanden PET-07 CC/CV power supply. In particular, we see how the voltage output can be controlled and how this clears up some ambiguity with the circuit design. In part three, we will *finally* attempt to communicate using RS-232 to monitor and […]

10 Apr 2016

Sanden PET-07 Power Supply RS-232 Module Reverse Engineering – Part 1

Sanden Title 1

In this video we take a look at the Sanden PET-07 CC/CV power supply. In particular we look at the RS-232 plug-in module and attempt to make sense of the signals between the main board and plug-in board. In part two, we’ll apply this knowledge to attempt to receive RS-232 data from the power supply. […]

22 Oct 2015

Protek 608 original Windows software

Protek 608 Windows software v1.02

I’ve finally managed to fire up the original Protek 608 software on an old Dell Inspiron 8100 I found stowed at the office. My previous attempts to run this software failed on Windows 8 and 10, and there’s very little information about how this software looks and operates (it’s quite niche). I decided that it […]

30 May 2015

Protek 608 RS-232 details

Protek 608 RS-232 login analyser

This is following on from my previous post introducing the Protek 608 multimeter and my software project. In this post I detail the communications hardware, an important consideration for future development. The Protek 608 uses an RS-232 connection to allow for interfacing with a PC. This is a very common connection that most DMMs used. […]