Nokia 3310 AVR library
With all these scrap phones and phone parts available nowadays, old Nokias in particular, it is very useful to learn how to interface reusable parts such as LCDs.
Microcontroller interfaced to 3310's LCD is ATmega8 and it also connects to USB port. LCD is based on Phillips PCD8544 controller and libraries are written in C. The source code also includes the "V-USB, virtual USB port for AVR microcontrollers" so LCD is actually controlled by a PC application.
AVR tutorial - IO registers
Protostack has announced their next AVR tutorial - "Introduction to I/O Registers". IO register is the way for microcontroller to interact with the outside world. So this tutorial will teach yout what are and how to use PORT, PIN and DDR registers on ATmega8.
The tutorial is, of course, in GCC.
Link dump 6.30.2010
On-board scooter computer
If you think that modding your scooter or a motorcycle with a simple battery indicator is cool, well, think again.
Whether you have a scooter or a motorcycle this add-on is a real treat. It is an on-board computer with color LCD touch-screen and lots of features: battery voltage indicator, time and date, temperature, lean gauge, current speed, max speed indicator, odometer, 2 trip meters, latitude and longitude readouts, compass heading readout and GSM/GPRS quad-band cellular module. It is all based on Arduino (ATmega168/328) microcontroller.
Smart scooter battery charger
Scooter battery problems, anyone?
This smart charger automatically starts the charging procedure when battery voltage drops below a certain predefined value and stops after the voltage has risen above the maximum allowed value. Setup can't be easier, just connect two alligator clips to battery terminals and plug the device in mains. This way it can stay connected for months and the battery will never overcharge. This comes very very handy when you have a scooter or a real motorcycle that you don't drive during the winter time.
Because we all know what happens to a battery when not used and especially during the winter.
IR tracking robot
Here is the latest creation found on Let's Make Robots and it is very very cool. It is an object following robot that follows you around the room.
Realization is on PICAXE microcontroller and it uses servo motor to turn the "head" or the "eye" towards the detected object. The "eye" has lots of transmitting IR LEDs and 4 pairs of receiving IR photo-transistors. The photo-transistors are connected to microcontroller's A/D converters for measurement of level of the reflected IR light.
Make sure you check the video of it in action!
Source: OddBot, Lets Make Robots
PhorseCode POV gadget
POV, again, is nothing new or revolutionary in display technology. This one is interesting because of a few things; it is very small - you can build it with SMD parts on a very very small PCB and power it with a 3V button cell battery; and it is programmable on the site with a single button input method.
It is built on Atmel ATTINY25 and it uses 3 data lines to control 6 LEDs. Now, this single button uses a strange code similar to Morse-code and it is named PhorseCode.
Source: Julian Skidmore
Beginner Project: Two Tone Siren
Siren is a very straightforward device but for beginners it is an excellent starting point since it directly interacts with real world via sound and is a great morale booster for next, more advanced projects that shall come.
Consisting of a very low part-count it can also be built on breadboard. This siren in particular uses two NE555 timers which can be replaced with just one NE556 - if you can get your hands on one. It is also called "Sweeping Output Siren" as seen elsewhere.