Limor Fried:one of the most influential Women in Technology 2010

She strikes again :) This time an entire article is dedicated to her on

I find this part really funny:
“They see how Adafruit is run, and say, ‘I’m gonna go off and start a company that makes 3-D printed robots!’” Fried says.

... because in our case, we thought we're gonna run off and start a company that makes energy monitors.

Definition of open-source hardware

The software and hardware of the OpenEnergyMonitor project are open-source.

Open-source software has been around for some time. The concept is simple to understand and relatively easy to implement. The source code with documentation is made available to all; usually a through a free online download.

Open-source hardware is a relatively new idea. Basically it entails the sharing of the hardware design (schematics, CAD files, documentation etc) so that the hardware can be reproduced and/or modified by someone else. Until now there has been no formal definition. A community derived official definition of open-source hardware is just been released:

Logo ideas for open-source hardware. To be printed on PCB's etc.

Below is another (newly submitted) logo I found on the forum. I really like this one. I think it combines the best features of the best two designs above. The only problem I can see is the circles being mistaken for pads and drilled out while drilling the PCB! 

A few tips from DIY Drones

I visit regulary DIY Drones, and two posts lately captured my attention because they are directly related to our project:

  1. Dronepedia: The first issue is the necessity of having a well done wiki for any Open Source project. A solid wiki would spare users a lot of time and many replicated discussions. I think it is time for the Open Energy Monitor to have a solid wiki, and the team here agrees on it. I guess we will roll it very soon. Needless to say, help is much appreciated.

  2. DIY electronics warranties: A serious issue for the DIY movement businesses, and small electronics makers in general. Where does your liability stop, and where does users responsibility begin? As Anderson puts it in his post, it varies from one company to another, while they are committed to delivering a minimum level of customer and technical support, other companies estimate that starting the moment where you power the components on, their liability stops. It is quite paradoxal indeed. I invite you to read the linked post ans share with us your opinions in the comments

A great talk by Saul Griffith on energy

A fantastic video:

Can we make this kind of analysis and sustainable energy plan at the community-group scale?

It would be really exiting to integrate the electricity energy monitoring hardware directly into such tools so that the larger context of energy use is easy to see.

Rearranging builds upon

I made a start on rearranging the builds upon page, I'd like to elaborate on the different ideas that the project builds from:
  • sustainability
  • open source design
  • personal fabrication
and explore the larger open source sustainable technologies ecosystem that is out there.


A few more designs:

- mains ac module
- multiple input pulse counter
- baseboard
- barebones CT Pulse RF unit

+ some example module connection diagrams at the bottom:

Next step is to order the components to test a few of these.

PCB Designs in development

The plan

Create a PCB's for each module that interconnect via standard 3-wire and 4-wire connectors. A PCB specifically for:

  • Mains AC v3 module
  • RTD Temperature sensing module
  • Relay module (may be able to use modules available for this)
  • multiple input pulse counter
  • Compatibility with the nuelectronics datalogging board.

Develop a baseboard that is an Arduino with normal shield headers but also with 3-wire and 4-wire connectors on the same PCB.

Develop a baseboard that is an Arduino with normal shield headers, 3-wire and 4-wire connectors and also tri-state buffer for master/slave network operation.

An barebones arduino with a CT or pulse input module and RF transmitter socket all in one.