Member #34964

Member Since: March 14, 2008

Country: United States

  • I followed the "Qwiic Pro Micro USB-C (ATmega32U4) Hookup Guide" and encountered several issues trying to get a Hello World program to work (clean Arduino install on Windows 10 and Fedora 32, all add-ons update, "Sparkfun SAMD (...) Boards->Sparkfun Qwiic Micro" board type selected). Here are a few tips for others intending to do the same:

    1) TXLED0 and TXLED1 macros were not recognized by the compiler. Rather than trying to resolve this, I just commented these lines out since they weren't critical for Hello World program.

    2) Serial1 (hardware serial) was similarly not recognized by the compiler. Likewise commented it out.

    3) Could not upload the compiled sketch. The Arduino/bossac software seemed to be initiating the bootloader reset via 1200 baud, but the timing was off and it was terminating on not being able to find the serial port. After 2 days of troubleshooting (double-tapping the reset button in sync with initiating the upload, manually setting the baud rate to 1200, etc), on a whim I changed the board type to "Arduino AVR Boards->Arduino Micro" and the upload worked flawlessly on board Windows and Linux. This also resolved the missing TXLED0/1 and Serial1 compilation errors above.

  • I know this is just copied from the datasheet, but "Extended spurious over 240 Hz..."? Maybe "Extended spurious frequency rejection over 240 Hz..."?

    Could the geophone be combined with this or this to create a through-earth communication system? Does anyone know the sound velocity characteristics of concrete or limestone?

  • What's the production quality like? From the photos of the one board, it looks like there is too much solder on the SMD parts, some components are not mounted squarely, and they didn't snap off the headers very cleanly. Are all the boards like this?

  • Connecting batteries in parallel isn't recommended. They aren't ideal voltage sources and differences in voltage (due to brand, age, manufacturing, etc) can cause the higher voltage batteries to discharge into the lower voltage batteries.

  • Another option is to connect your pull-up resistor to another MCU pin instead of directly to Vcc.<br />
    <br />
    Benefit:<br />
    + You can switch power to your pull-up resistor so that you aren't always drawing current, even when you aren't reading that pin.<br />
    <br />
    Draw backs:<br />
    - It takes up another MCU pin.<br />
    - Not very useful for asynchronous or interrupt-driven pins.

  • I would buy 5-10 of these if they were in the $15-$20 range and a matching step-up was available.

  • It looks like the manufacturer, Hanwei, also makes many other sensors. Could you carry ones for O2 and H2S specifically? I'd like to make a personal air-quality monitor.

No public wish lists :(