Spite, Thrift, And The Virtues Of An Affordable Logic Analyzer

[Larry Wall], the father of Perl, lists the three great virtues of all programmers: Laziness, Impatience, and Hubris. After seeing that Saleae jacked up the prices on their popular logic analyzers to ludicrous levels, [CNLohr] added a fourth virtue: Spite. And since his tests with a Cypress FX3 over the last few days may lead to a dirt-cheap DIY logic analyzer, we may soon be able to add another virtue: Thrift.

The story begins a year or two ago when [CNLohr] got a Cypress FX3 development board for $45. The board sat unused for want of a Windows machine, but after seeing our recent article on a minimalist logic analyzer based on an FX2, he started playing with the board to see if it could fan the flames of his Saleae hatred. The FX3 is a neat little chip that has a 100-MHz General Programmable Interface (GPIF) bus that basically lets it act like an easy to use FPGA.

Prepared to spend months on the project, he was surprised to make significant progress on his mission of spiteful thrift within a few days, reading 16 bits off the GPIF at over 200 megabytes per second and dumping it over the USB 3.0 port. [Charles]’ libraries for the FX3 lay the foundation for a lot of cool stuff, from logic analyzers to SDRs and beyond — now someone just has to build them.

The search for a cheap but capable logic analyzer is nothing new, of course. Last year, both [Jenny List] and [Bil Herd] looked at the $22 iCEstick as a potential Saleae beater.

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