this is a very long and detailed tutorial that I did a long time ago, check it out!
http://www.youtube.com/watch?v=tfO3uhZpQTA
This is a LED pocket watch. It has 12 LEDs to show the hour, 60 LEDs to show the minute, and 60 LEDs to show the second. The LEDs are arranged in three rings. There is a button on the top to activate the pocket watch, and a button on the back to change modes and settings.
http://www.youtube.com/watch?v=1YD8rQ0h6oI
The battery is a rechargable lithium ion coin cell battery and it is charged from a micro USB connector. The battery life depends on how heavily the pocket watch is used, but if you leave it alone, it is estimated to last several months. There is a low battery indication feature. This pocket watch also feature a buzzer and a vibration motor, which are used for the alarm feature, and the motor causes a short “tick” as each second passes by. The pocket watch is constructed of a PCB, two pieces of laser cut clear acrylic plastic, and a 3D printed casing.
Click Me!! More instructions, pictures, animations, and videos.
I made this thing that converts ordinary headphones into Bluetooth headphones. My laptop and phone both have Bluetooth so this will work great with them.

I got my Raspberry Pi. I do not have an ethernet connection or Wifi dongle available, or an extra keyboard. I don’t have any Bluetooth either. I needed a substitute keyboard to use the Raspberry Pi.
For fun, I designed a little USB device, actually it has two USB devices on a small board in the shape of a stick. Two USB capable microcontrollers are on this circuit. One will connect to the Raspberry Pi, and behave like a keyboard and mouse. The other will connect to my laptop. My laptop will run software that captures keystrokes and mouse events. The laptop will tell the microcontroller what to do, so when I press a key on my laptop, the Raspberry Pi thinks the same key is pressed. (and the same with the mouse)
http://youtu.be/iXMBKlIrzQs
We turned my phone into a universal remote that uses augmented reality. We can track the location of objects and identify them in real time, so we can overlay an icon representing the object on the video shown on the touchscreen. Simply click on the object to interact with it. It’s all wireless, no base station required.
http://www.youtube.com/watch?v=svA_LgLgTUE
Actual video is 1080p, I recommend you view it full screen.
Presentation slides: without notes and with notes
Photos:
http://imgur.com/a/oRjll
Our group did circuit and PCB design, we did the soldering, we designed the phone casing, we designed all the IR and RF protocols, we wrote our own firmware and Android app.
http://youtu.be/TYAl2s3tuMI
As I get more serious into my electronics hobby, I need to work with more SMD components. Some component packages are very difficult or impossible to solder with a traditional soldering iron. To solve this problem, I decided to hack a toaster oven to become a reflow soldering oven.
Here are some other old small projects. These are probably from my high school days. Some are from my university days. I’ve collected them all onto this one post when I moved my website.