HamRadio2008 made a demonstration video of the Bus Pirate in I2C mode. He hooked up the Bus Pirate to a test board he built with various I2C devices on it. He then used the I2C mode 7bit address scan to find all the addresses of the on board devices. Get your own handy Bus Pirate […]
Arthur entered his 74Clock into the Open 7400 Logic Competition. I uses a large 7 segment display and has a battery in case of power outage. A clock is a useful thing, so let’s build one. Via the contact form.
Daniel built a charge pump voltage inverter for the Open 7400 Logic competition. It uses the 74LV14 Schmitt trigger to provide a clocked signal, which is then connected to the inverted charge pump circuit to provide a -5V supply. Via the contact form.
Snorre built a Logic E-reader for the Open 7400 Logic Competition. It is a e-reader build completely from logic chips and 2 eproms. The e-books are displayed on a old analog oscilloscope. The front page says EEPROM instead of EPROM. I don’t have access to a burner right now, so i can’t fix it (ironically, […]
Viswesr wrote to us about the EFM32 MCU from Energy Micro: Recently, I discovered EFM32 MCU (ARM Cortex M3/0 based) from Energy Micro when looking for a very low power MCU. I was impressed on how this MCU reduces power consumption (refer: 10 factors that make the 10 factors that make the 32-bit EFM32 the […]
Jonathan entered his illogical Dickson doubler into the Open 7400 Logic Competition. My entry demonstrates how you can use the internal protection diodes and back powering to power a 74HC14 at a voltage “double” (minus diode drops) that of the primary power supply. This method was tested on a 74HC14 and a 74HC595, but it […]
HamRadio2008 demonstrates the Bus Pirate in UART mode. He is using a PIC18F45K20 MCU to read temperature data from a I2C sensor and then sends it over the UART to the computer serial port, via the MAX232 RS232 level converter. The Bus Pirate is used to monitor the UART signal coming from the board to […]
John’s second entry into the Open 7400 Logic competition is a working computer with serial I/O and a lights ‘n switches front panel. He built a 8bit CPU with a single accumulator, basic arithmetic (+,-,&,~,<<,>>), conditional branching and subroutines, as well as 1KB of RAM. After building and testing that it works, he unfortunately had […]
irrenhaus gave us a rundown on Frankfurter Buchmesse book fair he visited earlier this year. Here is what attracted his interest and ours: The art installation is the mainly interesting thing:For rows of 34 thermal printers each. All 136 thermal printers were printing – guess what – twitter messages. It was impressive – an impressive […]
Arup entered his USB device not recognized design into the Open 7400 Logic Competition. It uses a logic chip to stimulate a USB host just enough to get a “Device not recognized” response from Windows. Once the prank succeeds a “1” is displayed on a 7 segment display. Via the forum.
Felixls and Suky designed a PICKIT2 clone (machine translation) that works with both 3.3v and 5v devices. Using a 3.3v voltage regulator they have access to both the 5V USB and a 3.3V power supply. Simply by moving a jumper you can chose which supply will power the board and PIC. Via the forum.
Bruce sent us a picture of his free Bus Pirate v3c PCB build. If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – we’ll send you a coupon code for the free PCB drawer. Via the contact form. Get your own handy Bus Pirate […]
Giuseppe built his CMOS digital clock two years ago and decided to enter it into the Open 7400 Logic Competition. By using a 2Mhz quartz crystal and a 21bit counter he managed to make a 1Hz clock signal which drives his design. Implementing 2 binary counters programed to count to 60 he managed to get […]
Here is a video from Hive 13 that shows how an Android tablet is used to control a glass block LED matrix via a wireless connection. After installing a LED matrix behind a glass block wall in their bathroom, hackers at Hive 13 are figuring out a way to control them. After some initial struggles […]
John entered his four digit RPN calculator into the Open 7400 Logic Competition. This is the fist of two entries he made while attending “Digital Hardware Lab” courses at the University of Utah. It is a 4 digit RPN calculator that can add and subtract, designed entirely out of logic ICs. The first few weeks […]
Markus decided to reuse an old Commodere 64 Competiton Pro joystick, so he added a USB adapter to it. The retro joystick uses a simple interface over the D-SUB 9 connector, using one connection for each movement direction and one connection per button. He used a PIC24FJ64GB002 microcontroller to translate the native joystick interface to […]
Ajoy built a TV pattern generator for the Open 7400 Logic competition. Using 74C14 Shmitt inverters to generate various timing signals, he later combines them using a few NAND 74C00 gates to get a B&W TV video signal generator by CCIR-B standards. A full write up explaining the operation of his circuit, along with the […]
Bertho entered his Lights out game into the Open 7400 Logic Competition. After working out the math behind lights out, Bertho decided to make his own using only logic chips. The object of the game is to turn the lights off by using a + shaped mask.The board automatically generates random patterns over a 5×5 […]
R-B built a heart rate measurement from fingertip circuit. He also provided all the design files, and general theory of it’s operation: This project describes a microcontroller based heart rate measuement system that uses optical sensors to measure the alteration in blood volume at fingertip with each heart beat. The sensor unit consists of an […]
Reminder to all those interested in entering their projects into our Open 7400 Logic Competition: You only have two days left to send your entry in. Entering Entries can be posted on in our forum, on your personal blog, or even a handy how-to site like Instructables. When you’re ready, please submit a link to […]