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jwatte

Member Since: September 20, 2011

Country: United States

  • Product GPS-11571 | about 5 months ago

    I’m developing a rover, and I was using a Sirf-III USB puck that would not get a lock indoors. After about 15 minutes of warm-up, this device actually does get a lock, although somewhat intermittently. I wired its UART to a Atmega32u4 and forward the NMEA stanzas to gpsd over USB. I will have 20-60 second periods of “no fix” and then as much time of “3D fix” as viewed by xgps. So, yay for better sensitivity! But it’s not yet perfect.

  • Product ROB-12629 | about 5 months ago

    I don’t think so. I think the rise/fall is already included in the “poles.” 8 poles means 4 magnets. 4 magnets timesd two poles/states each (north and south, high-and-low) times two encoders equals 16 transitions/counts. I could be mis-understanding how the poles are counted, though.

  • Product ROB-12629 | about 5 months ago

    8 poles and 2 encoders should give you 16 counts per revolution. 360/16 is 22.5 degrees per count. With 100 mm wheels (4") that would give you about 2 cm per count. I’d like to know what the output is – is it totally raw Hall sensors that need conditioning, or is there any clean-up of the signal to turn it into something nice? (Answered my own question: The outputs are open-drain, so all the clean-up needed is a pull-up resistor.)

  • Product WRL-11373 | about 7 months ago

    I have one of these, but actually want to just do 3.3V I/O. Can I use this board as a simple break-out board, by connecting to the IN/OUT pins on the sides, rather than the DIN/DOUT pins at the bottom? And if I only have a 3.3V rail, would connecting this to both 3.3V and 5V make sure the regulator doesn’t break? (back-feeding regulators is a bad idea in general, but equal potential should be safe)

  • News - Why You Should De-Rate Ca… | about 7 months ago

    Tantalums have a lot longer lifetime than electrolytics when treated right, though. If you want to build for the next 10 years, not just the next 1 year, consider tants your capacitor of chocie.

  • Product SEN-11345 | about 7 months ago

    The live geiger counter feed seems to have flatlined.

  • Product LCD-11315 | about 10 months ago

    So my statement is totally true: If you buy this version of the display from Sparkfun, it will be totally useless to you without also having a custom 4D cable, AND running the 4D Windows software at least once. It would be great if these requirements were actually clear in the product description. SparkFun offered a refund, and I bungled that by not sending the thing back in time, so SparkFun was okay on this, but would still be better off with a more detailed description of the limitations.

  • Product LCD-11315 | about 10 months ago

    Is there some undocumented way to turn the default firmware, which just runs code created using Windows tools and downloaded with a custom 4D cable, into recognizing serial commands for drawing, without also buying the custom 4D cable, and installing and running the Windows software? There is nothing documented on the 4D site.

    Also, I don’t understand what you mean by “open source.” I just talked about “open systems.” Different animal entirely, and all of the engineering wins we’ve had in the last 30 years have largely been driven by open systems rather than closed systems.

  • Product WRL-08687 | about a year ago

    This board actually has a ground plane in the “keep out” area from the Xbee data sheet. That means this board will have somewhat worse range than a board that adheres to the guidelines, especially for boards with chip antennas!

  • Product LCD-11315 | about a year ago

    I cannot actually use this “serial” display in “serial” mode because I need a 4d special usb cable and a Windows computer to actually make it “serial.”

    Also, if you think Windows still has 90% market share among your target market, you should get better market research. And if you think a crummy, custom language is better than providing libraries for tools that developers have been using forever and can integrate with any environment, I think you’re needlessly locking your hardware or of the market.

    4dgl and the effort your company spends on it is largely wasted and a bad idea. Open systems beat closed lock-in every time.

No public wish lists :(