Circuit-Zone.com - Electronic Projects
Posted on Monday, July 18, 2011 • Category: FM Transmitters
This 2 Watt FM transmitter will provide 10km range in good weather conditions. Use dipole antenna for maximum range. Transmitter can be tuned between 88-108 MHz with c5. BB204 could be replaced with conventional led (big) with reverse bias (no light given in correct polarity). 9v power for 2km transmission with good sound quality and up to 18v for 10km range. 2N3553 RF transistors may be replaced with 2N4427 or 2N3866.
Posted on Monday, July 18, 2011 • Category: AVR
I wanted to share my project of modifying the temperature sensor project and turning it into a thermostat with ATmega168. I added a digital output to drive an LED to "warm" the temperature sensor when the current (actual) temperature falls below the desired temperature.
Two push buttons come in as digital inputs one to ramp the desired temperature up and the other to ramp it down.
The logic is simple bang-bang control to turn the LED on and off based on the relationship of actual temperature to desired temperature. It simulates a thermostat in heater mode. The LED is off when the current temperature is above the desired temperature and turns on once the current temperature falls below.
Posted on Monday, July 18, 2011 • Category: FM Radio / Receivers
This radio works with solar batteries that provide voltages between 0.5 and 2V. Microphones should be magnetic, high impedance (2k or more). The coil is wrapped around a ferrite rod 1 cm in diameter with 28AWG wire.
Posted on Monday, July 18, 2011 • Category: Miscellaneous
LCD character displays can be found in espresso machines, laser printers, children’s toys and maybe even the odd toaster. The Hitachi HD44780 controller has become an industry standard for these types of displays. This tutorial will teach you the basics of interfacing with a HD44780 compatible display using some DIP switches and a few other components.
Posted on Saturday, July 16, 2011 • Category: AVR
USB AVR Programmer for Atmel AVR microcontrollers. USB AVR Programmer is made of an Atmega8 and few components. The programmer uses a firmware driver that makes this programmer attractive to many amateurs.
Another thin why this programmer is so popular is because it is officially included and supported in WinAVR.
Once again lets see what this programmer is made off and how to set it up.
The core of USB AVR Programmer adapter is Atmega8 microcontroller clocked by 12MHz crystal. Soldered board is ready to be connected via simple USB cable with B type connector (Computer side needs A type of connector). Resistors R2 and R6 are current limiting resistors, that protect computer USB port. Resistor R7 helps computer to recognize device as LS (Low Speed). Diodes D1 and D2 indicates about data transfer. Header SV1 is compatible with STK200/300 just 4 and 6 pins are used for RXD and TXD (may be used for other purposes).
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