Didik Rostyono developed nice converter from battery povered 12V DC power supply to 110V and 50Hz wave. To acchieve this he used microcontroller 89S2051, MOSFET switching circuit and transformer. Output signal then is filtered where higher harmonics of signal are filtered and signal appears to be sinusoidal. It is hard to say what loads this circuit is cappable to drive, but this design [perfectly suits for learning purposes. Continue reading
Tired of using huge batteries in embedded design? Well Guy from Spritesmod managed to power AVR microcontroller from single AA battery with simple circuitry which is driven by AVR microcontroller itself. As industrial devices uses DC-DC converters to rise voltages like from 1.5V to 5V and so on, there is same principal used as well, just DC-DC converter control is done bu AVR MCU itself. He didn’t use dedicated PWM control chip, but managed to drive converter with PWM generated with Attiny13 this way occupying one timer for this. Here is this fancy circuit. Of course to before MCU can generate control signal it has to start, for this there is starter button used, which rises voltage for short time to suitable when pushed. Then microcontroller starts and continues powering itself. With MOSFET switch efficiency of circuit reaches up to 73 percent. Main advantages of such powering method are low part count, soft poer off. But in other hand efficiency is still quite low and there is timer and one MCU pin occupied. Continue reading
At the end of academic year ECE476 Cornell University students produced about 40 new projects mostly based on Atmega32. As every year students have their responsibility to choose their own final project. So there you can find various interesting ideas and designs including video games, robots, MIDI synthesizers, clocks, speech recognitions 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
The goal of this project was to build affordable mobile tracker. Device can be put in a car where it can trigger an alarm when car gets stolen. Device itself is very simple as GSM module already comes with GPS module (GM862) built in. Alexander Weber connected this module to Atmel’s Atmega8 microcontroller (circuit) and communicated using serial modem communication protocol. Device can send text SMS message with device GPS position data. Project author provided only eagle circuit. Continue reading
