May 28, 2010
News - Free Day 2011 Recap
about 4 years ago
Two Ideas for next year:
Nice: Quiz again, but this time put the loyalty money decision on the first question page. Then no more zero-attempt disappointments.
Diabolical: Scavenger hunt through the SparkFun Catalog.
about 5 years ago
For the benefit of those considering a purchase:
I’ve been in touch with SparkFun and confirmed that I actually have the 1-axis chip due to an error on my part. So, shop with confidence.
However, understand the schematic. SparkFun has included high pass filters on the break out board which may make the output not quite what you expect.
A common request from a gyro is for it to tell you its rate of rotation. By integrating that rate over time you’ll be able to estimate changes in pose. Unfortunately the high-pass filter eliminates information about slow-changing rates. If you rotate the chip at a constant speed the output will initially register a rotation but eventually will slide back to reporting 0-rate, even though you’re still spinning.
The parts are tiny, but if you can flick off one of the resistors and bridge across a capacitor, you’ll disable the high pass filter. I did that, and I can now get usable data. If you want to try it, check the SparkFun schematic to identify the right parts to remove.
Previously I reported a DOA X-axis. After closer inspection, I see the chip is marked Y530AH – I think I’m just holding the Z-axis-only version of the chip. I think that’d be an easy packing mistake, as they use the same board.
The strange behavior from the one “working” channel isn’t answered yet, but I’ll get in touch with SparkFun tech support.
The X-axis on mine (both 1x and 4x) was clearly dead on arrival. No response to motion at all.
I had some hope for the Z-axis, which was the only one I cared about. When bouncing it around in my hand, it seemed responsive in about the right way. Now that I’ve gotten around to testing on a spinning table, it doesn’t seem to respond correctly at all. If you let it spin down to a stop, the output will overshoot and takes more than a full second to recover to the zero-value. Weird.
A suggestion. Your engineers are making some design decisions when they choose what pins to break out and what discrete components to add to the break out board. A quick application note for how they intended the breakout board to be used would be very helpful. For a board like this, that would be really easy for you to do and would answer the majority of the questions that pop up in the thread.
No public wish lists :(
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