jcarmody Posted January 23, 2009 Report Share Posted January 23, 2009 Hi, I need a USB I2C adapter (with LabVIEW drivers) that I can use to replace an existing part. I've been using TotalPhase's I2C Host Adapter but can't get one fast enough. It's a long story... Can you recommend one? Thanks, Jim Quote Link to comment
Louis Manfredi Posted January 23, 2009 Report Share Posted January 23, 2009 Will NI's 8451 do the job for you? I've got one, seem to recall it was economical, and definitely was pretty easy to set up. (not that my I2C traffic was all that easy, but that too is a long story) at any rate, the 8451 is working fine for me. Best, Louis Quote Link to comment
jcarmody Posted January 23, 2009 Author Report Share Posted January 23, 2009 QUOTE (Louis Manfredi @ Jan 22 2009, 05:43 PM) Will NI's 8451 do the job for you? I thought of that as I was driving home. It'll work fine, but they cost 2X the Aardvark. That brings me to another point in this sad story. I need a new one because my existing station went down this morning when a bad UUT put 28V to the clock and/or data lines. I had a spare! ...which, they promptly destroyed this afternoon. Any idea how I can protect these lines? Quote Link to comment
jed Posted January 24, 2009 Report Share Posted January 24, 2009 I helped design this one for Jova Solution, and wrote the LV driver. $300. http://jovasol.com/hardware/tims0100_overview.htm They probably have one in stock, could overnight it to you. Tell 'em Jed sent you. QUOTE (jcarmody @ Jan 22 2009, 04:13 PM) I thought of that as I was driving home. It'll work fine, but they cost 2X the Aardvark.That brings me to another point in this sad story. I need a new one because my existing station went down this morning when a bad UUT put 28V to the clock and/or data lines. I had a spare! ...which, they promptly destroyed this afternoon. Any idea how I can protect these lines? Quote Link to comment
crelf Posted January 24, 2009 Report Share Posted January 24, 2009 QUOTE (jcarmody @ Jan 22 2009, 07:13 PM) I need a new one because ...a bad UUT put 28V to the clock and/or data lines. ...Any idea how I can protect these lines? Yeah - don't put 28V on the clock and/or data lines Quote Link to comment
Dan DeFriese Posted January 24, 2009 Report Share Posted January 24, 2009 QUOTE (crelf @ Jan 23 2009, 08:31 AM) Yeah - don't put 28V on the clock and/or data lines This happens sometimes... You may want to check on getting a replacment IC from FTDICHIP. I've never opened the Ardvark but I believe its little more than an FT245BM inside. Could save you some $ to just repair the Ardvark. As far as prevention... A small series resistor and Zener shunt may help. ~Dan Quote Link to comment
Louis Manfredi Posted January 24, 2009 Report Share Posted January 24, 2009 Haven't priced Aardvarks lately, but I guess they must be around $400 the pair. Doesn't seem like that much, but if your DUTs are going to throw 28 v in inappropriate directions with any regularity, I guess it can add up. Sounds to me like you might need some high power zener diode protection circuits-- Perhaps backed up with fuses. Transorb is one brand protective diode I've used before. Also some current-limiting resistors might help, especially in combination with the diodes. Might also be possible to opto-isolate the inputs, but that can get dicey if your running at a high clock rate. (Whatever you do, be sure that the protection system also flags the DUT as bad. Seems quite likely that any DUT sick enough to put 28V on the clock lines would also fail any reasonable tests, but it wouldn't do to protect the tester and have the DUT blow up its target system instead.) Best Luck, Louis Quote Link to comment
PaulG. Posted January 24, 2009 Report Share Posted January 24, 2009 Note that the 8451 will function as slave mode in an RT system only. In Windows it will only work in master mode. Quote Link to comment
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