Interfacing Nokia 6100 color LCD to AVR controller

Thomas Pfeifer has connected Nokia 6100 132×132 pixel 4096 color LCD to an AVR microcontroller. LCD is also used in Nokia 6100, 7200, 6610, 7250, and 6220. He connected LCD to Atmega8 microcontroller: There are two types of displays: with Epson chipset(S1D15G10) and Philips(PCF8833), he wrote code for Philips chipset. Firmware is written in AVR-GCC language, where images can be uploaded via serial cable. Also there are few videos view sample video on how it works AVR-3D-Engine. Continue reading

Programmable DC power supply

This is a must-have tool in your LAB. The idea was to build a microcontroller-based DC power supply witch was easy to assemble and was cheaper than in the market. Device was built by using only standard components. Device is capable to provide up to 30V 2A. Power supply unit can be controlled by PC using i2ctalk program which can be run under Linux, Windows, Mac OS X and Solaris. Software can be found here. Don’t forget to check for an updates. You can order this power supply unit as a kit from Tuxgraphics online shop. Kit includes additional documentation and circuit diagrams. Continue reading

AVR DDS waveform generator

This AVR DDS generator can generate signals from 1Hz up to 65535Hz. Thanks to well known DDS algorithm, frequency limits can be much higher, but signal resolution drops in higher frequencies. The current range is enough for most audio signal equipment testing. DDS algorithm is written in software where Atmega8 runs at a maximum 16MHz. There are several signal waveforms available: sine, square, sawtooth, triangle, reverse sawtooth and pseudo-random noise.   Signals are stored in lookup tables as the DDS algorithm requires. Signal output is organized via simple R-2R ladder DAC. LCD signal goes through the shift register; this way, only 3 MCU pins are used, while others serve for other purposes – buttons other outputs. The project is well documented PCB and source files included. The author states that he will build another DDS generator with improved control and variable signal amplifier at the output.   Continue reading

Power AVR microcontroller with AA battery compactly

Are they tired of using huge batteries in embedded design? The guy from Spritesmod managed to power the AVR microcontroller from a single AA battery with simple circuitry driven by the AVR microcontroller itself. As industrial devices use DC-DC converters to rise voltages from 1.5V to 5V, there is the same principle used as well, AVR MCU itself does just DC-DC converter control.   He didn’t use a dedicated PWM control chip but managed to drive converter with PWM generated with Attiny13, occupying a one-timer for this. Of course, it has to start before MCU can create a control signal. For this, a starter button is used, which raises voltage for a short time to be suitable when pushed. Then microcontroller starts and continues powering itself. With the MOSFET switch efficiency of the circuit reaches up to 73 percent. The main advantages of such a powering method are low part count and soft power off. But on the other hand, efficiency is still relatively low, and there is a timer and one MCU pin occupied. Continue reading

Cornell University AVR student projects

At the end of the academic year, ECE476 Cornell University students produced about 40 new projects primarily based on Atmega32 every year, and students have the responsibility to choose their final project. So there, you can find various exciting ideas and designs, including video games, robots, MIDI synthesizers, clocks, speech recognition, and so on.   Projects here are accumulated since 1999 Spring(over 200 older projects). So you can surf inside pretty big knowledge base and find ideas, solutions and inspiration for your own designs.   Continue reading