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 […]

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. […]

10 Feb 2016

Electronics Workbench – Part 4 – Putting it together

Here is the design and build of my compact DIY electronics workbench. This is located in the garage / workshop in a house that I’m renting, so I’m building it to be portable and transportable in future. In this forth episode I complete the hutch shelving, mount some component trays, and more!

9 Feb 2016

Electronics Workbench – Part 3 – Design Review

Here is the design and build of my compact DIY electronics workbench. This is located in the garage / workshop in a house that I’m renting, so I’m building it to be portable and transportable in future. In this third episode I temporarily install the lighting and load the shelving to assess the design so […]

8 Feb 2016

Electronics Workbench – Part 2 – Shelf system modifications

Here is the design and build of my compact DIY electronics workbench. This is located in the garage / workshop in a house that I’m renting, so I’m building it to be compact and transportable in future. In this second episode I modify the hutch shelving system to raise it’s height and mount the peg-board […]

7 Feb 2016

Electronics Workbench – Part 1 – Cabinet modifications and lighting

Here is the design and build of my compact DIY electronics workbench. This is located in the garage / workshop in a house that I’m renting, so I’m building it to be compact and transportable in future. In this first episode I describe how I will convert a cupboard into the workbench and my ideas […]