This is a simple signal generator which produces sine waves (or any waveform really) at audio frequencies using DDS and is controlled a USB serial connection.Only 2 chips are used in this circuit. The AVR ATmega88 which produces the signal, and an FT232R for the USB interface. While a computer is required to control the varying frequency of the oscillator, a fixed frequency project could be made without the USB interface. [via]
USB controlled DDS signal generator with ATmega88 - [Link]
Here is an experiment with an 8×8 LED matrix, driven by a MAX7219 IC, controlled through an Arduino micro-controller board. A custom PCB has been made by Tan from DinoTech to tidy up all the wires connecting the LED matrix and the IC. It comes with a separate 12V power supply, in order not to drain everything from the Arduino board. [via]
Arduino with 8×8 LED Matrix - [Link]
The length of the sleep cycle varies for each person, and averages about 90 minutes. I wanted to try to measure the length of mine, without having to wake up and check a clock. I also wanted to get an idea of how much I naturally move around during the night, and what patterns I might find therein. [via]
Sleep Tracker - [Link]
The RMS G-meter is a microprocessor-based device that displays and updates in real time the RMS values of the acceleration levels to which it, itself, is exposed, in one axial direction.
This device consists of a single-axis accelerometer, signal conditioning/filtering, A/D converter, micro-controller, LCD display, and battery power supply. Once turned on, the user may first select either Peak mode, Average mode, or Integrated RMS mode. In the Peak Mode, the device updates the highest RMS value it has measured since it was activated. In the Average mode, the device simply displays the averaged RMS value of signal over the entire time it has been active. In the Integrated RMS mode it reports the sum total of all RMS samples computed since activation (total integrated RMS). [via]
RMS G-Meter – [Link]
A touch sensor developed for use in a range of projects for fabrica interactive. The sensor is designed to take a reading and then communicate that reading digitally so that the sensor can be placed at a distance away from whatever is reading it (A microcontroller / other physical computing interface)
The sensor can be used with conductive ink that can act as an input area once its been applied to any appropriate surface. (windows, plastic, etc) [via]
Fabrica Touch - [Link]
As Oil prices going up and seems this is going to keep that way, more and more attentions is given to alternative energy sources. Probably solar energy is most attractive due to its nature. Don’t go in to discussions about what alternative energy is the best – all of them are good as long as they are effective.
Researchers in University of California, San Diego have been working on “hairy” solar cells. They discovered that growing nano-wires on photocells boost solar cell efficiency. Nanowires help to conduct electrons from collections surface to electrode.
Higher efficiency solar cells with nano-wires – [Link]
Looking for compact but flexible, simple and cheap development board? You should consider this nice list of microcontroller USB-Stick tools. These are special development tools that include all necessary hardware and software in a portable USB stick. Most of them consist of two parts – USB stick and attachable target board. [via]
Microcontroller Development tools on USB stick – [Link]
I wanted to build an etching tank since i first saw one in an article on Make Blog. It was fun to make it and it will sure speed-up my PCB making process. The main thing that i wanted to achieve with my etching tank was to keep it thin so it holds up smaller amounts of etchant, it’s better this way because i need to store and work with smaller quantities. My finished tank holds 1,5 L of liquid when full.
PCB etcher with aquarium pump and heater - [Link]
Did you have an old Nokia 1110 cell phone that keeps lying in the drawer, but you just don’t know what to do about it? Well, guess what! Is time to show off your creativity by combine the Nokia 1110 LCD with the PIC Interface (Yeah, it sounds like a cool idea, isn’t it?).
Before you starting the project, you have to make sure that your old Nokia 1110 LCD screen is in a good condition (Well, it would be better if the screen did not have any scratches). [via]
Nokia 1110 LCD and PIC Interface – [Link]
If you are interested in seeing what is going on with your garden this Garden Monitor Project is something you should take a look at. It is using a Picaxe microcontroller and has an interesting home brew communication process. All of the schematics and source code are also provided.
“One day we had a good hard rain and I could see it the graph of the data; the surface temperature suddenly dropped, the light intensity dipped, the humidity rose, and the three inch moisture sensors indicated an increase. Later that day I was on the phone with my girlfriend and she said it had also rained early in the morning (I must have slept through it;) I looked at the data again and there it was… now that I knew what to look for I could see from the data that it started raining at about 05:10 in the morning. That’s when it struck me that this thing really does work!”
Garden Monitor Outdoor System - [Link]