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stej

Member Since: January 9, 2014

Country: United States

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white and nerdy

  • I want to reiterate what solves a common issue with this board.

    I was trying to simply interface a USB keyboard to an Arduino and having one weird issue. It would work on a RedBoard but not consistently. Randomly it would just stop working and swapping USB devices did not work at all. On an Uno I got the “OSC did not start.” consistently. :@

    PIN 7 of the Arduino is tied the reset pin of the MAX3421E. If this pin is not set to OUTPUT then it will drift causing the MAX3421E to reset at random. If you are using the USB_Host_Shield_2.0 code that everyone points to then this pin is not set by default. Simply put this code before Usb.Init() in your code and all your problems will be solved!

    pinMode(7,OUTPUT);
    digitalWrite(7,HIGH);
    
  • I gave up trying to control the LEDs directly with the Raspberry PI and added an Arduino Pro Mini in between. Everything works as expected now.

  • I’m looking at the datasheet and wondering if the source voltage and logic voltage should be the same; 3.3v?

  • Random flashing might not be the correct way to describe it; its more like the segments randomly change as if they are getting a signal to display something else.

    There is a motor but its completely separate running on 120 volts. There is however a beefcake relay turning the motor on and off. When the relay is switched the display changes.

    I’m controlling everything with a Raspberry Pi. Is it possible that the 3.3v GPIOs are the issue?

  • I’m having a noise issue. I have 4 of these strung together with the large 7-seg displays and the segments will flash randomly during normal operation.

    I was at the Sparkfun factory last Friday and noticed that Nate’s safe-cracking robot’s sign had capacitors on each digit. I didn’t make a note to the size of each cap or where exactly they were placed but I’m thinking my noise problem will be solved with these caps.

    Could someone give me some guidance on adding caps to my large digit driver to minimize noise?

    Thanks, Jonathan

  • The fact that this is happening on my BIRTHDAY is a sign that I should participate!!!!

  • How about replacing the RGB LEDs with NeoPixels?

  • https://github.com/alexwhittemore/AlexW-Eagle-Libraries

  • I guess not.

  • Looks awesome and I’m sure it runs great. However my dyslexic mind keeps seeing the model number as a word that is synonymous with the stuff a dog would leave on your lawn. Consider putting a dash “-” between the letters and numbers of the model number.