6502s are 8bit microprocessors from the 70s developed by MOS Technology. Sweet thing is they come in DIP-40 trough hole packages, although we doubt an emulator based on 7400 logic chips will fit the same package. Check out André’s DIY 6502 computer for the Open 7400 Logic Competition. I have built a DIY 6502 computer, […]
Author Archives: DP
A simple EMF probe
Always wanted to look at the electro-magnetic soup of signals sloshing around you. Tuomas made a device that let’s you watch these signals on your scope. It consists of an inductor that picks up the signals, and an amplifier that well amplifies them so you could watch them on your scope. Check out a video of Tuomas […]
Outtakes from the New York Trip
This a collection of interviews that didn’t make the final cut in our Global Geek Tour of New York video.
Another toner transfer circuit board making guide
Sometimes prototyping your boards needs to be done quickly. Etching boards at home is the quickest way to knock up simple designs. There’s tons of ways to do it, one of the most popular is the toner transfer method. A circuit design is laser-printed on glossy paper, then transferred to a clean copper board with […]
I2C multiplexer shield controls 8 independent I2C buses
Sometimes I2C addresses can over lap, or maybe you need to use more than one of the same device. The I2C multiplexer shield is a way to control 8 I2C buses from a single I2C peripheral on a microcontroller. Voltage translation is also handled by the multiplexer chip. It was built on an Arduino shield […]
Workshop Update for October 10th, 2012
Today we worked on editing Tomorow’s video. In case you’re wondering the video’s topic is video editing. We also put together today’s basic tutorial for LEDs. We worked on the 1.8” TFT breakout board as well. We added a joystick, a protection diode, and moved some capacitors around.
7400 competition entry: 4049 inductance meter
Mike’s 4049 inductance meter converts inductance into voltage, which can be read via any multimeter. Check out the latest Open 7400 Logic Competition entry: All the decent multimeters nowadays seem to have a built in capacitance meter, but only a few of the really expensive ones have a built in inductance meter. Dedicated inductance (LCR) meters, of course, […]
Control Raspberry Pi’s GPIO pins via a web page
This Instructable might just complete your plan to take over the world with the Raspberry Pi. Control R-Pi’s GPIO pins via a web page. Install some soft, type in a few commands, and you’re set. The base package includes: – A server program that runs on the Raspberry Pi to read variables – A MySQL […]
Ringo3 LED clock assembly
Community at it’s best, one forum member helping another. Matseng sent a Rino3 clock PCB to Arup, which he populated even before the Matseng got a chance to build his own. They are now debugging it together: Few days ago I received one ringo3 PCB from forum member masteng. It’s having 60+60+12 LEDs (ss,mm,hh). The […]
INTRO GUIDE: Basic light emitting diodes (LED)
Image by kaktuslampan: CC BY-SA Probably the most used device in out projects is the humble LED. They’re in almost every piece of equipment around us. While LEDs are simple to use, we get a surprising number of requests for a LED tutorial. This guide is an introduction to LEDs. Not just how to light […]
Free form nixie tube clock
Looking for something cooler than the typical nixie project? How about a nixie project done entirely in free form, no PCB style. Matseng designed this nixie clock around a single IN-1 nixie tube. It periodically reads out the time, digit by digit. It’s a clock made of a single IN-1 Nixie tube controlled by a […]
Workshop Update for October 9th, 2012
All mail backlog from Maker Faire should be cleared. Applied for a new China visas for an upcoming trip to Seeed, super easy but the commute is time consuming. This is the last one that Ian can fit into his passport without visiting the embassy for extra pages. Today we put together the initial schedule […]
7400 competition entry: TV Auto-off from the ’80s
Are you tired of watching TV and want to turn it off quickly from your armchair? Viktor’s TV Auto-off shows you how: The idea was to have a tiny light come up right next to the TV after a preset period of time. If my grandpa is watching TV he would notice it and press […]
How to build a surface mount resistor and capacitor collection
This tutorial shows how to easily, and relatively cheaply, build a nicely organized SMD resistor, and capacitor collection. George likes using connectable tiny storage boxes, and filling them with resistor/capacitor kits from eBay. This is complemented by printing out labels for your storage boxes using the label design files for download. Via Twitter.
Eagle Parts: TD62783 8Ch high voltage source driver and the 2.1mm barrel jack
Latest parts added to our Eagle library are the TD62783 8Ch high voltage source driver and a 2.1mm barrel jack footprint using oblong plated through holes. The TD62783Ch is a 8 channel high side switch, we intend to use it in our VFD boards. Check out the DC barrel jack schematic symbol, and all of […]
#FreePCB via Twitter to 2 random RTs
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]
BitBltBlade – WiFi controlled POV lightsaber
Madox designed the BitBltBlade, a WiFi controlled POV lightsaber designed to display images in conjunction with long exposure photography. The BitBltBlade uses the hackable TP-Link TL-WR703N router and Kean’s USB Expander board to wirelessly control a strip of RGB LEDs. The concept of operation is that the user would use their smartphone which can upload photos […]
Bluetooth controlled RGB LED strip
Hmms shared his Bluetooth controlled RGB LED strip project. Atmega8 microcontroller with the Arduino bootloader controls the LEDs, while the Bluetooth communication is handled via a cheap serial to Bluetooth module. I wanted the strip to be Controllable via a PC or a Mobile Phone.So I decided to make my own RGB LED strip Controller […]
Workshop Update for October 8th, 2012
Today we worked on today’s 3D model of the VFD tube board. Due to a large number of surfaces in this model, our PC had trouble coping with it. But we’re proud of the final render result. We added a few components to our library. One of which can be seen in the picture above. […]
Open 7400 prize: Audio Spectrum Analyzer from YourITronics
YourITronics donated an Audio Spectrum Analyzer to the Open 7400 Competition. Get your entry in and this and other cool hardware can be yours. Thank you to YourITronics for sponsoring the 2012 Open 7400 Logic Competition!