How-to: Programmable logic devices (CPLD)

Complex programmable logic devices (CPLDs) contain the building blocks for hundreds of 7400-serries logic ICs. Complete circuits can be designed on a PC and then uploaded to a CPLD for instant implementation. A microcontroller connected to a CPLD is like a microcontroller paired with a reprogrammable circuit board and a fully stocked electronics store.

At first we weren’t sure of the wide appeal and application of CPLDs in hobbyist projects, but we’ve been convinced. A custom logic device can eliminate days of reading datasheets, finding the ideal logic IC combination, and then waiting for chips to arrive. Circuit boards are simpler with CPLDs because a single chip with programmable pin placement can replace 100s of individual logic ICs. Circuit mistakes can be corrected by uploading a new design, rather than etching and stuffing a new circuit board. CPLDs are fast, with reaction times starting at 100MHz. Despite their extreme versatility, CPLDs are a mature technology with chips starting at $1.

We’ve got a home-etchable, self programming development board to get you started. Don’t worry, this board has a serial port interface for working with the CPLD, and doesn’t require a separate (usually parallel port) JTAG programmer.

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How-to: USB remote control receiver

Now that we listen to MP3s, and watch XVIDs or x264s, a computer is the entertainment center in at least one room of most homes. Unless you have a special HTPC, though, you’re probably stuck using the keyboard to pause, change the volume, and fast-forward through annoying Mythbusters recaps. PC remote control receivers range from ancient serial port designs (who has one?) to USB devices not supported by popular software. In this how-to we design a USB infrared receiver that imitates a common protocol supported by software for Windows, Linux, and Mac. We’ve got a full guide to the protocol plus schematics and a parts list.

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How-To: Web server on a business card (Part 1)

For years, Microchip PIC microcontrollers dominated; PIC16F84 hacks and projects are everywhere. The 8-bit 16F and 18F lines are supported by several coding environments and easy-to-build serial port programmers. Microchip’s 16-bit PIC24F is cheaper, faster, and easier to work with, but largely absent from hacks and projects.

We recently used a Microchip PIC24F microcontroller in a mini web server project, but didn’t find many introductory references to link to. In this article we’ll cover some PIC 24F basics: support circuitry and programming options. We’ll also talk about our favorite features, and how we figured them out. Our next article will outline a web server on a business card based on the PIC 24F.

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How-To: The Hacker’s Soldering Station


A good soldering station and fume extractor is a must for anyone interested in hacking and modding, but not everyone can afford the expensive professional models on the market. This How-To and the tips within it will guide you through the process of building an inexpensive homebrew fume hood complete with built-in time and temperature controlled soldering station and all the soldering tools you need.

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How-To: Etch a single sided PCB


Making a PCB is very simple; it does not consume a lot of time and the results look professional. After reading this How-To and watching the step by step video, you will be able to make your own PCB in your workshop using just a few inexpensive materials.

Many people use protoboard and point-to-point wire everything, but needing multiple copies of the same circuit is the reason that forces many away from using protoboard. After making your first circuit board, you might not point-to-point wire anything again!

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FPGAs rock


I was doing some project window shopping today, and FPGA’s came up on my list. [John Kent] put together a pretty impressive documentation set. He’s written up some of his own projects, some how-to’s and linked plenty of good information for the budding FPGA programmer.

How-to: Make your own XBox 360 Laptop (Part 3)


[Ben] finally got part 3 of his XBox 360 laptop how-to finished up. This is the final piece of the series. He spends it covering wiring up the ports, buttons, keyboard and final assembly. There are plenty of shops that handle special order laser cutting – so don’t begin to think that this sort of project is out of your class. If you’ve ever built a model car and can handle a soldering iron, you can definitely build one of these on your own.

I was just checking for this final piece this morning – but props to [Tony] for noticing it first.