If you’ve got a graphic LCD lying around you can build this four-channel logic analyzer with a couple handfuls of cheap components. [Ronald de Bruijn's] design uses a PIC18F4580 to sample up to four logic inputs at a maximum resolution of 2 MHz. He’s included the PCB artwork so that you can etch your own board. Having a logic analyzer around can really make your life easier, allowing you to reverse engineer communication protocols and troubleshoot your own design problems.
Hackaday alum [Ian Lesnet] has been working in cahoots with a dedicated team of developers to produce the OpenBench Logic Sniffer. This caseless logic analyzer can operate at 100MHz and sample 32 channels at once. Better yet, a digital oscilloscope add-on is in the works. The pre-order comes in at $45, that’s a lot of functionality for just a few greenbacks. We’ve embedded a demo video after the break that details installing and using this device under Ubuntu.
[Oliver] received the Telly Terminator as a gift and decided to take a closer look at it. This key fob has two buttons; one shines an LED like a flashlight and the other turns off televisions. Sound familiar? Yeah, it made [Oliver] think of the TV-B-Gone as well.
He cracked open the case to find just a few components. The brain behind the IR signals is a Helios H5A02HP. Only a few pins are used for outputs so he connected a logic analyzer and recorded the signals. His writeup covers the process quite well. He takes a known IR transmitter protocol and compares it to the capture from the logic analyzer. It turns out that the fob generates 46 different signals and with further analysis concludes that there’s a chance the code used here is from an older version of the TV-B-Gone source.
Hackaday alum [Ian Lesnet] tipped us off about some reverse engineering of the HVR-1600, an analog and digital television encoder/tuner. The project was spawned when [Devin] noticed his Hauppauge HVR-1600 didn’t tune channels in Linux quite as well as it did in Windows. He had a hunch this was due to improper initialization settings for either the tuner chip or the demodulator.
To fix this he used two test points on the board to tap into the I2C bus. Using a logic analyzer he captured the command traffic from the bus while running Linux, then while running Windows. By filtering the results with a bit of Perl, and comparing them by using diff, he tracks down and finds the variation in the commands being sent by the two drivers. After a bit of poking around in the Linux source and making the necessary changes, he improved the tuning ability of the Linux package.
[Devin's] work looks simple enough, and it is. The difficult part of this process is being smart enough to know what you’re looking for, and what you’ve got once you’ve found it.
posted Mar 6th 2009 1:58pm by Ian
filed under: reviews
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.
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.
In a two-part series called “PS3 Fab-to-lab” on IBM’s awesome developerWorks website, [Lewin] explains how to use the Cell Broadband Engine in a PS3 to create an audio-bandwidth spectrum analyzer and function generator. The set up consists of Yellow Dog Linux, an NTSC television, and an external USB sound card to provide the inputs of the spectrum analyzer and the outputs of the function generator. The sound card driver is written to simply capture or send the info in question (audio range only) and the NTSC television as the graphical interface. This hack involves a lot of coding with hardly any example code provided. The article is more of a guide than anything. If anyone gets this working, let us know!
