When I was at Maker Faire this year (2013), my friend Phil Sittner came up to the Atmel booth and told me that I had to see something on the other side of the show floor. Phil is the guy that built a $400 network analyzer kit a few years ago. So he takes me over to the Saleae Logic booth. Lo and behold he had managed to find a small, inexpensive logic analyzer housed in a beautiful billet aluminum case.
Saleae makes two versions—the $300 Logic 16 has 16 channels. You can sample two of them at 100MHz, or 4 channels at 50MHz, 8 channels at 25MHz, or all 16 channels at 12.5MHz. The Logic 16 has an input voltage range of -0.9V to 6V, and works with 1.8V, 2.5V, 3.3V, and 5V systems. The original model, the $150 Logic, has 8 channels that you can sample at 24MHz. Logic accepts voltages from -0.5V to 5.25V, and has standard CMOS thresholds of 0.8V for logic low, 2.0V for logic high.
Nathaniel and Jonathan were clearly proud of the beautiful job they did with Saleae products. An engineer from Gould Biomation told me designing test equipment is a real challenge since it has to be better than whatever it is testing. He confided that Gould designed to typicals and just swapped boards until they got a machine that met the spec.
At the Maker Faire booth Nate and Jonathan had the Saleae logic analyzer hooked to an Atmel-based Arduino. Any working engineer can appreciate the tiny footprint of the Saleae Logic analyzer. I remember consulting at Teledyne 15 years ago where we had the classic and expensive HP 16500 mainframe. It was nice because you could stuff a 2GHz scope card in one the slots, but the thing was gigantic. Since it was so big you had to push it way back on a shelf out of the way. That meant you had to reach out and lean to touch the screen or spin the accursed single-knob user interface. Our solution was to get a mouse for it so we could interact with it no matter how far back it was on the bench. Even the pods were big, larger than the entire Saleae Logic 16. As Russell Crowe said in Master and Commander “What a fascinating modern age we live in.”
Speaking of fascinating and modern—check out a screen shot of the Saleae Logic analyzer. It’s obvious the device can sort through basic logic problems. But Nate told me you can also capture higher-level protocols to help you figure out what is going on in your SPI ports. My consultant buddy John Haggis says any serial port will eat up 6 person-months of time to get working. That is not just hooking up the wires, but getting all the low-level and high-level protocols and error conditions figured out. He was half-joking, but I suspect he is closer to the truth than far from it.
Nate told me he would send me a Logic 16 to try out. You can bet I will be showing it off to Eric, Phil and my other pals at the next eFlea breakfast. My mechanical engineer pal Dave Ruigh will be especially delighted to scope out the Saleae, since he was the guy that made a billet aluminum Palm case years ago. I hope Nate realizes that my maniac friends will whip out tiny tools and have his beautiful Logic 16 in pieces on the table—that’s what happens when you toss cool hardware at a group of engineers. It’s like raw meat to hungry lions.