Logitech MX510 high pitched noise solved!

10 Jun 2012

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!

electronics,
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DIY Electronic Derailleur on Instructable

06 Jun 2012

Fritzing diagram

Servo mounted on a Shimano Tiagra derailleur

Electronic shifters

Mounted Electronics

‹ ›

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.

electronics, tutorial, cycling,
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Open source Bluetooth 4 breakout board means no more Mi-Fi

09 Apr 2012

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.

electronics, weekend project,
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rlcDB: Online electronic parts management

26 Jan 2012

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.

electronics, rlcdb, webapps,
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My low cost and open source tools

14 Jan 2012

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.

Read more

open source, electronics,
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2nd revision of the OBD Adaptor as arrived

12 Jan 2012

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.

electronics, obd,
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OBD-2 Testing Update

24 Dec 2011

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.

electronics, obd,
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OBD-2 Build Update

20 Dec 2011

Top: STN1110 + supporting electronics

Bottom: Bluetooth module

I finally finished assembling the OBD-2 board yesterday. It has taken a while because I've been working on an exciting web app for hardware engineers, which will be launching in a few days. I will continue to update the schematics on github, but I don't recommend building version 1.0. There are a couple of layout and footprint issues I want to workout first. Next up, testing.

electronics, obd,
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OBD-2 PCBs arrived

28 Nov 2011

The board is super tiny at 5cm x 5cm. Unfortunately, some of the passive components are really close together, which will make things hard to solder. Next revision I'll switch to 0603.

Source

electronics, obd,
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Home Energy Prototypes

15 Nov 2011

Web Interface Version 1 with a Google look and feel

In my previous post I talked about my motivations for building a home energy monitoring system like lack of open data and expensive monthly plans. Today I'll share some of my prototypes and future plans.

electronics, home automation, smart home,
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