OpenBeacon RFID transceiver project

Open 2.4GHz RFID project is free design of active RFID device. Device has it own unique serial number which allows to identify it among others. Also device may have additional information that can be read. OpenBeacon can transmit and receive radio signals what allows to use it for variety purposes like tracking, and remote control.   Open beacon heart is Microchip PIC16F684 microcontroller with Nordic Semiconductors 2.4GHz NRF24L01 front-end chip. Transmitting range of beacon indoor reaches up to 25 meters. And 80 meters in open air. There is only beacon tag and USB reader circuits and firmware available freely. USB reader is built under AT91SAM7S123 ARM7 microcontroller which firmware can be compiled with GNU ARM-GCC compiler. Project authors says, that the next step would be to change the current node CPU (PIC) into an ARM based microcontroler with USB connection and the possibility to use GNU C/C++ compilers for programming issues. Also with small software modification at least two tags could communicate to each other without the need for base stations. Well seems like nice project to stick with. Continue reading

AVR chip computer runs basic programs

Jörg Wolfram has been developing interesting project so called AVR-ChipBASIC on Atmega32. Simply speaking this is a basic language programmable chip computer which his capable to run basic programs and with ability to display results in RGB TV screen.   This is almost fully functional computer system that have many functions including: RGB-TV 23 rows with 30 colums, NTSC/PAL per jumper selectable; prepared for FBAS encoder; 256 characters with pseudo-graphics, 8 colors; PS2 keyboard; simple sound (1 channel, 1 voice, noise); serial port (1200Bps only) with charge pump; parallel printer port, also usable for IO and ADC; I2C-port for data EEPROM and temperature sensors; ISP port is also able to handle Atmel dataflash; mostly Tiny-BASIC compatible with many improvements; 4 programs to 51 lines are stored in flash; built-in full screen editor; serial load/store via text transfer, listing print; screenshot function; integrated monitor with single step, breakpoints. Programs can be edited and run directly on TV screen and run from AVR chipbasic menu system. Also program can be saved, transferred via terminal or even printed. Firmware is updated constantly so… Continue reading

Single board computer for image acquisition and processing

This project was developed by Flavio Ribeiro as at the University of São Paulo‘s Polytechnic School of Engineering. It uses ARM9 (AT91RM9200) microcontroller running at 190MHz speed.   Board specifications are: 180 MHz ARM9 processor (Atmel AT91RM9200); 3 MPixel Micron MT9T001 CMOS sensor; Altera Cyclone FPGA with 6000 LEs; 2×32 MBytes of SDRAM (32MB for the ARM9 and 32MB for the FPGA) 16 Mbits of serial flash 1 10/100 Intel Ethernet interface 1 high speed USB 2.0 interface 1 SPI interface 1 serial (RS-232) interface Board runs ARM Debian Linux from USB key-drive. CMOS sensor is accessed by FPGA. It reads image frames that can be processed further by FPGA or ARM9 microcontroller. It seems quite challenging project to play with. Continue reading

Easy to build auto-range capacitance meter

If your multimeter doesn’t measure capacitance or you want to have wide auto-range capacitance measurement capabilities then try this project. Capacitance meter measurement range is quite large (from 5pF up to 2600μF) and of course range is selected automatically.   This capacitance meter like others use charging time measurement technique (τ=RC). Circuit is really simple. There are three buttons used. Two of them are used to calibrate capacitance meter in order to remove stray capacitance. Third button is used to save calibration data to EEPROM memory. You can download assembly source code compile and burn to PIC16F873A microcontroller. I guess this is a nice tool that fits in to collection. Continue reading

Siemens S65 color display oscilloscope

Do you want to have color display oscilloscope? Then make one from Siemens S65 color display.   Circuit is really simple – two channel analog inputs are directly connected to Atmega32 ADC inputs. But anyway oscilloscope is capable to display up to 40kHz wave form at 10 bit ADC resolution. Whole program is written in Bascom language. Continue reading

Multimeter for power supply unit

This multimeter was build as an addition to power supply unit by Zbyszek.   This unit uses ATMEL Atmega8 microcontroller which reads voltage (0…30V with resolution of 10mV), current (0…99A with resolution 10mA) and displays information on LCD. All you need is to mount multimeter to PSU module according to this diagram. Do not connect to voltages more that 50V as this may be dangerous for adapter and you. Author uses this multimeter for charging of RC Li-Pol cells. For this purpose you need to flash desired firmware which displays capacity passed to load, this way you can see how much cells are charged. Continue reading