Logitech MX510 high pitched noise solved!

Over the last few months I've noticed a really annoying high pitched noise in my room. I just figured it was one of the many devices in my room or maybe it was all in my head. Turns out it was my Logitech MX510 mouse! According to this great website Logitech is pulsing the wheel encoder LED at 5KHz and the harmonics create a 15KHz tone in one of the crappy capacitors. Solution? Just replace C11 with a 0.1uF tantalum capacitor. Also removed the metal thing under the scroll wheel to get smooth scrolling!


DIY Electronic Derailleur on Instructable

Servo mounted on a Shimano Tiagra derailleur

I've posted an Instructable showing how to build and install an electronic derailleur. If you like this project please vote on the Instructables page. This has nothing to do with my bike computer and is meant for people who enjoy building stuff themselves. A more complete and finished product including my bike computer is in the works. 

For now the Arduino sketch, schematics, Fritzing diagram, bill of materials and CAD diagrams can be found on the github.


The Open Goldberg Variations

The Open Goldberg Variations, by Kimiko Ishizaka, has released their recordings in the public domain for everyone to enjoy. It started as a Kickstarter project last year as did MusOpen, which is on a similar mission. Enjoy.



Open source Bluetooth 4 breakout board means no more Mi-Fi

nRF8001 Breakout board layout

One thing I always need for my hardware projects whether I'm working on sensors for the home or a fitness device is a low power, cross platform and affordable wireless module. I've used HopeRF modules like the RMF22B for their affordability and low power capabilities, but because they don't use any standard wireless protocol I'm forced to make adaptors for endpoints like smartphones or computers. Wireless standards like ZigBee partly solve this problem, but off the shelf modules are expensive and still don't help if you want to talk to a smart phone. One might think Bluetooth is the solution then, but in the past power efficiency and range were a problem if you were building a temperature sensor for example. Also, you had to be a certified Apple accessory developer if you wanted to make a Bluetooth accessory for the most popular smartphone in the market. Well, all of this has changed with Bluetooth 4.

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electronicsweekend project

OLinuXino - 30 EUR, open source, hand solderable Linux computer

If you have been following my smart home project you'll know that one of the improvements I was working on was developing a simple Linux computer to act as an internet gateway and web server. This type of product can be very useful for many projects where having a full operating system can make life much easier.

I chose the iMX233 processor from Freescale because it is affordable in small quantities ($8.39 from Newark) and comes in a QFP package, which is important to be able to hand solder it. Another downside of BGA packages is they require higher tolerances and therefore more expensive PCBs to manufacture.

Yesterday I was directed by Nelson Neves to a very similar project already in production by Olimex. This is how Olimex describes it


OLINUXINO is Open Source software and Open Source Hardware, low cost EUR 30 Linux Industrial grade single board computer with GPIOs capable to operate -25+85C.
People keep comparing OLINUXINO with Raspberry Pi and BeagleBone project, so we would like to state the differences here:

Although the projects are similar there are different goals and implementations:

OLINUXINO is completely open source - including hardware and software, this means you have access to all CAD files and sources and you can reuse them for your own personal or commercial project.
There are NO restrictions to manufacture and sell these board for your own use or resale.
OLINUXINO use widely available microcontroller iMX233 which cost USD 5.50 in 100 pcs quantity, this means that people can spin off their own boards and manufacture them cheap as the processor is in TQFP easy to assembly by hobbyist package.

RASPBERRY PI have no released CAD files nor complete schematics, RPi uses processor from Broadcom which is not available for sale in small quantity, it uses BGA package which require expensive setup to assembly.
RPi is designed to be home gadget, OLINUXINO will work in industrial environment -25+85C and will be designed to be low cost but NOISE immune.

BeagleBone have open source CAD hardware files but uses BGA processor and BB board is very complex and hard to manufacture in small quantities.
Source: https://github.com/OLIMEX/OLINUXINO
Olimex Blog: http://olimex.wordpress.com


Weekend Project: Likelist.ca = About.me + Pinterest

UPDATE: Source code on Github

Introducing www.likelist.ca. A way to share all of your likes and favorites from across the web. You can think of it like about.me except with your 'likes' from various social networks embedded on a Pinterest style page. 

Planned Improvements

Infinite scroll, more services, pop out images for a larger view, user thumbnails, personal pages, visuals for tweets with no links and instructions :)

Unfortunately, Facebook doesn't provide a users likes without authentication, which defeats the purpose of having a public like list and Google Plus doesn't have an API for retrieving +1's yet.

webappsweekend project

rlcDB: Online electronic parts management

Here is a preview of my yet to be released web app.

It is a BOM manager for electronic parts. Get it? rlcDB. I created it because I needed something that would integrate with my EDA tool, keep track of inventory and make ordering from distributors easier.

The way it works is you upload your BOM from your EDA tool like Eagle CAD and the app does its best to try and find the correct part. It then looks up attributes and gives you part numbers that you can paste in each distributors quick order form. It also shows you the cost/availability of each part from each distributor at the bottom.

Every time I think I'm going to release it I find a reason not to so I have no ETA.

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My low cost and open source tools

In the 1970s software developers worked together to build a foundation of open source software tools with the hope that the entire community would benefit from this shared knowledge. Three decades later the software industry has accelerated at an incredible pace and offers a slew of sophisticated open technology to everyone. Everything from distributed currencies, compilers, operating systems, software algorithms, encryption tools and more are available as open source software. This has had massive implications for security, human rights, research and distribution of knowledge.

We are starting to see the same thing happen with the open source hardware movement with projects like the Arduino. Companies are able to innovate faster with the help of thousands of community developers and testers. It has allowed me to do my work at a fraction of the cost and effort it might have even just 5 years ago so I thought I would share some of my favorite tools.

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open sourceelectronics

2nd revision of the OBD Adaptor as arrived

Got the 2nd revision of my Bluetooth OBD adaptor (left) from Iteadstudio (+郑志煜)
Their Open PCB service allows you to get 2 free random PCBs if your project is open source. I got a Smart Modular Platform Power Module from designed by +Dino Tinitigan (right) and a PCB breadboard (top) similar to+Adafruit Industries Perma-Proto designed by +Zachary Heilig. Cool service.


OBD-2 Testing Update

OBD-II Adaptor connected to an Android tablet

I finished testing the OBD-II adaptor board this week on a Toyota Camry. As you can see in the picture the board had a few bad connections, but nothing that couldn't be fixed with a few jumpers.

I was able to get a number of stats from the free Torque Android app like
  • Throttle position
  • Engine PSI
  • Collant temperature
  • Engine Load
  • A number of Diagnostic Trouble Codes
  • O2 sensor voltage
  • Revs
One interesting note I learned was the evaporative system test reported as incomplete, which Toyota supposedly repaired during my last visit! Next up, test the remaining OBD-II protocols and bluetooth range. Expect a new revision in a few weeks.


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