How to make a very slim watch and keep battery life long? In this Hack-a-Gecko project, they tried to catch two birds with one stone.
We thought it would be cool to utilize the extremely low power EFM32 in combination with an extremely low power display to create a wrist watch demo application. And usually, the smaller and thinner something is, the cooler it is. (Admittedly, wrist watches do not necessarily follow this trend… big watches.)
Anyway, we wanted it slim. The starting point was the memory LCD display from Sharp (link). It is truly a Nano ampere display technology. And it is also thin, only 0.75 mm. A watch also needs a battery, cool new technologies exist such as the Thinergy battery, but the voltage of 4.1 V is a bit awkward. We decided to use a standard 3.0V CR1616 cell as it can power the EFM32 and display directly. Thickness of battery + display is 2.35 mm, is it possible to design the electronics as well within this thickness limit…? Challenge accepted!“
„The CATaLOG project aims to track our two cats Bobbin and Tuffin as they go in and out of the house so we can see which cat spends more time outside, what their favourite time to go out is, and also get sent SMS messages if a cat goes missing for a certain amount of time.
The system is designed around the Arduino Microcontroller linked to a low cost RS232 RFID reader and uses the Arduino Ethernet Shield and a Linksys WAP11 router acting as a wireless network bridge to send the data over the internet.“
„To see how well this idea worked I decided to build a small robot and a few applications to control it last weekend. The result of this is the Forknife Android G1 based robot, the RoboComm android application, and the RoboServ java server which I am happy to say work well. An overview of how the entire system works may be seen below.
In case others are interested in this, stuff, I have made my code for the robot, server, and android application available under the GPLv2 license. Please don’t get too upset with me if the code isn’t very polished.. I threw this together pretty quickly. At least I commented it! Be thankful :)“