50MHz frequency counter

This is one nice frequency counter developed by Peter Cousen. This is really low cost frequency counter as it uses elements available world wide.   The frequency meter can measure frequencies with 1 Hz resolution when measured frequency is up to 100kHz. Other features include: Auto-ranging with floating decimal point. Up to 7 digits displayed. Auto-adjusting gate speed (0.1 sec to 1 sec). Simple, ease to assemble, and highly stable readout. Sensitivity approximately 100 mV RMS (100 Hz to 2 MHz), 800 mV RMS @ 50 MHz. Input overload protected. Circuit and firmware are available for download. You may want to check out modified version which allows counting up to 80MHz. Continue reading

LPC213x development board

If you need simple LPC213x ARM microcontroller series test board you should try the one Ulrich Radig has constructed.   Board itself is simple but it covers all I/O that allows to cover all microcontroller functionality. Project files are available for download in Eagle CAD format. Continue reading

Dead reckoning robot platform

This is nice project made by Ibrahim Kamal. His aim was to create robot which navigates by using its position data log. The hardest thing was to record distance and turning angle because of these parameters depends how precise robot is manoeuvering from reference point.   Author provides really good theory analysis of dead reckoning process and how this was transferred to 89C52 microcontroller which counts encoder disc pulses for distance and controls steering motor which controls the angle of robot turning. Also all operation data is displayed on 2x16LCD module. Continue reading

Cascaded big 7 segment digits

If you need really big 7 segment LED display, you may want to build 6” size display modules that can be cascade connected in row up to eight digits.   Each module is controlled by PIC16F876A microcontroller and LEDs are driven by ULN2803 Darlington array chip, because one port needs to light 14 bright LEDs what consumes higher currents than port can handle. Project files and CCS C compiler example program are available for download. Continue reading

Simple 89S52 Project Board

Board has been developed by Wichit Sirichote. It can be used as general purpose development board for various project. For example author have used it for temperature, AC outlet, current measurements with additional current to voltage circuit connected to ADC input.   Board itself has 2x12bit ADC inputs, 4-digit seven segment LED indicator, connector for alphanumeric LCD, four switches, 16 I/O port pins for digital data communication and ISP adapter (89S series allows ISP programming). There are couple example programs like temperature sensor reading through ADC input. So it may be practical board to have or simply to learn 89S52 microcontrollers. Continue reading

GPS tracker prototype

Thomas Pfeifer decided to experiment with Tyco X1029-A-53 GPS module. He built a Atmega8 prototype board which reads GPS data and logs it to MMC/SD card every 1 second. So later data can be analysed on computer or simply put on top of the map (easy to do with Google map) to see the where did you go.   He made several experiments by driving with bicycle around around his place. In one of them he managed to draw his name on the map. Continue reading