Discrete Logic Driving Game Development

September 25, 2011 by Mike Szczys 3 Comments

[Caleb] is hard at work on a driving game based on 7400 series logic chips. This will be his entry in the Open 7400 Logic Competition, and it really outlines why this contest is especially tricky.

The concept behind the game is quite simple. You’re the driver of a car (the red dot at the bottom of the display square seen above) and need to navigate the curves in the road as you drive along. It’s the same game as we saw played on receipt paper back in June. [Caleb’s] using and LED matrix as the display, and we’re confident that if we grabbed our favorite microcontroller we could have this up and running on an 8×8 bi-color display in an afternoon. But doing it without the crutch of a programmable chip really brings out the clever engineer inside of you.

The circuit seen above is a Logisim proof-of-concept that [Caleb] went on to test on the breadboard. He thought he had everything figured out until he realized that his Data Flip-Flops were very occasionally not powering up in the same state as he predicted. Don’t worry, he found a solution to the problem. But we can’t wait to see what other hurdles he encounters as he pushes on toward completing the project.

Get Out The Graph Paper Get Started On The New Discrete Logic Contest

September 2, 2011 by Mike Szczys 23 Comments

Here’s another chance to ply your hacking skills for cash and prizes. Dangerous Prototypes has just announced the Open 7400 Logic Competition. First prize is $100 and a bunch of hacking goodies. But even better is that since it was announced, more sponsors have stepped up to increase the kitty, and the number of entries that will get prizes.

The parameters for entry are wide open. You can design anything you want, with emphasis on originality. Make sure you take plenty of pictures and document the project along the way. Their judging will take into consideration the amount of detail posted about the project (hence the ‘Open’ in the contest title).

Need some ideas to get you started? We enjoyed the useless machine that used a 7400 NAND gate. You could always build a time piece of some sort like this no-microcontroller clock. Perhaps hardware control like this stepper motor driver is more to your liking?

[Thanks Moderboy]

Binary Clock Using Logic Chips And Mains Frequency

January 16, 2011 by Mike Szczys 29 Comments

[Osgeld] built himself a binary clock. He didn’t take the time to explain his project, but he did post beautifully hand-drawn schematics and pictures of the circuit (PDF) as he was building it. We’ve seen clock projects that use mains frequency as the clock source and that’s the route that [Osgeld] chose for his build. He started with a 9-12V AC wall wort as a power input. From there it’s just a matter of using a bridge rectifier to convert to DC, then a 7805 linear regulator to establish a steady 5V rail. A resistor and a couple of diodes allow him to pull the 60 Hz frequency off of the incoming AC, and then use a combination of 4000 and 7400 logic chips to count the pulses and keep track of the time.

Lazarus-64, Not Actually 64 Bit But Still Blows Our Minds

September 29, 2010 by Jakob Griffith 16 Comments

Lazarus-64, breadboard game system; certainly sounds like something from the 1980s. We were surprised to find out not only the name, but also all the ICs used are only those available from the retro age of 30 years back (Save for the AVR controlling everything, of course). Even more amazing is how it has 256 flicker free color support, while not using NTSC chips. Which Goes to show that even if there are common solutions out there for cheap, building or compiling your own is not necessarily a bad thing or a waste of time.

There is a whole lot more to Lazarus, including double buffering and VMS, but sadly it appears progress has stopped on the Lazarus-64 breadboard game system, with the last update being last year. But we can still bask in the amazing glow that currently is.

ZeroPlus Logic Cube Modification

March 30, 2010 by Caleb Kraft 128 Comments

the folks over at OpenSchemes are at it again. This time they’ve cracked open a low end ZerPlus logic analyzer and modified it to function the same as the higher end model. The 16 channel version they purchased appeared to be fully capable of handling the 32 channels of the more expensive model. The installation of the additional components looks like it might be somewhat difficult, but it is certainly cheap.We love seeing things upgraded for cheap. You might recognize OpenSchemes from when they upgraded the DMM tweezers or hacked the USB serial adapters.

[via HackedGadgets]

Open Source Logic Analyzer

July 23, 2009 by Gerrit Coetzee 20 Comments

[youtube=http://www.youtube.com/watch?v=kqwtzUUPqu8]

[Jack Gasset] sends in the logic analyzer he’s been working on. The logic analyzer boasts an impressive array of features, it can sample 32 channels at 100MHz, 16 channels at 200MHz, SPI, UART, I2C and more. The analyzer’s maximum sample size is 4K for now, and it supports RLE to reduce the memory consumed. The analyzer connects to a java client on a standard PC via USB. The open source hardware based on a Xilinix FPGA can be purchased pre-assembled for $100 which makes it a direct competitor for the Salea logic analyzer we reviewed earlier this year.

Tools: Saleae Logic, Logic Analyzer

March 6, 2009 by Ian 65 Comments

A logic analyzer records bus communications between two chips. If you’ve ever had a problem getting two chips to talk, or wanted to reverse engineer a protocol, a logic analyzer is the tool you need to spy on the bus.

The Logic is a USB logic analyzer with eight channels and sampling rates up to 24MHz. Among hobby-level logic analyzers, the Logic has a good mix of features and decent sampling rates. We’ve been following Joe Garrison’s work on the Logic for a long time. If you’ve ever considered bringing a product to market, you can learn a lot from Joe’s blog that documents his development process.

When it debuted, the Logic was so popular that it was hard to buy one. It’s now widely available, and Saleae gave us one to try. Read our review below.

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