Frequency counter up to 70MHz

Herbert Dingfelder known as DL5NEG among radio amateurs have constructed a microcontroller based frequency counter up to 70MHz.   Frequency counter can use prescalers what allows reading GHz with 10kHz resolution. Without prescaler device can measure frequency up to 70MHz with 10Hz resolution. I think this is very good what simple schematic can offer. Hex file is ready for download and can be flashed to Atmega16. Continue reading

GPS and temperature logger on PIC

This project was intended to be used in weather balloon which logs position and temperature data read from LM75 temperature sensor. Device has 64kB EEPROM memory for storing data.   Device position can be sent via SMS by using mobile phone. Also there is ability to connect and control devices with relay. All project files are available for download. Continue reading

AVR logic analyser via USB

Lucas have posted useful project in μlabs. Logical analyser is very handy tool when working with digital electronics. Buying one sometimes may be to expensive and not worth an investment. So why not to build one.   Device sends data via USB to PC where it can be viewed and analysed in convenient window. Device uses external RAM which is used as data buffer – this allows to avoid bottel neck of data transmission due to low internal AVR RAM. Project files and necessary software is available for download. Dont be scared description is in German language. So use any translator available on line. Continue reading

Countdown timer for UV PCB exposure

If you need simple, reliable countdown timer for PCB exposure or even in the kitchen – this project is what you may need. Circuit of this timer is very simple – AVR Attiny2313 microcontroller gets commands from three buttons (Time Up, Time down and Start), displays it on 2x16LCD. You can connect any device to be controlled to relay. After timer counting is over – it gives a sound signal via buzzer. Project schematic and PCB is developed with Eagle CAD software. Firmware is written in Basic language with Bascom. Time to cook. Continue reading

Multipurpose programming tool for microcontrollers

Benedikt Sauter have been working on on USBprog – an open source multipurpose tool which supports AVRISP MKII, ARM7/ARM9 programming, JTAG debugging, simple USB to RS232 conversion or 5 line I/O.   This is interesting concept as you don’t need to worry about adapter firmware. You just need to connect to online firmware pool and update adapters firmware. As project is completely open source you can download schematics and USBprog base firmware and build adapter by yourself, or you can grab preassembled adapter jus for 22 Eur. Works on Windows, Linux and other operation systems. Continue reading

Handy temperature controller

Jesper have built this thermostat to control electric heating element. For this he used Dallas thermal sensor DS1621 which can be read via I2C interface. He used AVR 2313 series MCU for reading sensor data and displaying it on 2 seven segment LED indicators.   Controlling relay toggle point is made easy – Just two buttons UP and DOWN. Pressing both buttons at same time allows to set hysteresis and LED refresh duty cycle. Nice thing that device has power supply converter built int that is ready to be plugged anywhere in you need to control temperature. Circuit and source code is available for download. Continue reading