OCT7
SPI interfaced large 7-seg led display
This is the general purpose extra large (but doesn't have to be) DIY 7-segment LED display that can be interfaced to any microcontroller.
This project is really easy to build and at the end has only three wires to receive data from uC. It doesn't contain microcontroller itself, but is built around serial-in-parallel out shift register 74HC595 for each digit. Segments are switched by ULN2003 transistor array and LEDs in each segment are connected in series to consume less current. Number of possible digits in display is not limited!
Source: Wichit Sirichote
OCT6
Color-changing LED glowies
This is pretty sweet project for beginners in PIC microcontrollers. It is a device that glows red when heated and blue when cooled.
Microcontroller used in this project is PIC12F675 with built-in A/D converters. Two identical silicon diodes are connected to two analog inputs, that will change it's forward voltage drop when ambient temperature changes. One of diodes is used as a reference and the other to detect a change in temperature. Device is powered from a 3.6V Ni-Cd battery which is constantly re-charged from a solar panel. Source code is written in PIC Basic and is available for download on project page.
Source: I Make Projects
OCT5
Great PIC micro DIY development board
If we want to work with microcontrollers it is a great advantage if we own a development board. If someone can't afford to buy one, he or she can build one themselves.
Here you can see a development board for PIC microcontrollers PIC16F877 / 874. There is no programmer on board but the programmer can be built by using just a few resistors. On project page there is also a development board for PIC16F84 micro. Both of these boards are very well built!
Source: F. Iacopetti
OCT2
Video overlay circuit with ATmega8 - OSD
Video overlay is a technique of displaying a video information on a screen that's already displaying some image or a video. This technique is usually used in OSDs (on-screen display).
To display anything over an existing video signal you would need an IC that is built just for that purpose, such as teletext chips that display teletext info on a TV or even MAX7456 OSD chip. In this project, only ATmega8 is used to generate data and mix it with the existing video signal. Along with microcontroller there is also an LM1881 circuit that is used to extract timing information (sync) from the original video signal. This additional IC simplified the firmware in microcontroller.
Source: Gary N. Dion
OCT1
Nokia 1100 LCD with PIC microcontroller
Sometimes it is necessary to add an LCD display to our microcontroller project. We usually decide between character display such as 2x16 with HD4470 IC or other graphic displays.
Here we can see a driver for a graphic LCD display from Nokia 1100 phone which is good or even better solution than previously mentioned ones, especially because these displays are very very cheap. Driver IC on this LCD panel is PCF8814 which even though has I2C protocol support - doesn't use it. Instead it uses simple bit-banging mechanism for communication. Microcontroller that was used in this project is PIC18F1320 and source code is written in C and it can be ported to any other PIC microcontroller.
Source: SpiralBrain's World
SEP29
Miniature projector with lasers
So far we have seen many POV displays and how they operate. This time we are talking about the POV projector with lasers.
This laser projector consists of 8 red laser pointers, a drive motor for the mirror that rotates and disperses laser light onto the surface (a wall). Microcontroller does the same thing it does in the POV - turns on and off lasers in precise timing intervals so that it projects wanted text or a graphic image!
Source: Stefan Marti
SEP25
AVR development board - prize winner
For all of those who don't know, there was a prize contest held here. The contestants could only be those from nearby countries (local population).
The sponsor of this contest was Protostac with their beautiful AVR development board with ATmega168. It really makes a great package in combination with their AVR programmer. Also, for all those who like Arduino this is a great and cheap starting point as the board supports Arduino ATmegas with their bootloader.
SEP22
Dice value readout using Arduino AVR
How cool would it be to make your own true hardware random number generator? With this dice scanner we are already half way through.
This device consists of 5 IR pairs (transmitter+receiver) which are positioned under the dice. Although there are 9 possible pip positions, the value is read out by scanning only 5 of them. The brain of this thing is an Atmel Arduino and the read value is displayed on a 7-segment LED display.
Source: Steve Hoefer
