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USB host shield and arduino LED flicker

+ Forums > Help and Questions > USB host shield and arduino LED flicker


daniel
Screen%20shot%202011-02-01%20at%201.43.43%20am
Posts: 4
 		Posted 2012-08-09 04:02:21 UTC Reply

Whenever I run the usb host shield using this library: https://github.com/felis/USB_Host_Shield_2.0 and the Usb.Task method in main loop, the arduino LED turns on flickers dimly and I no longer control it using digitalWrite(13, HIGH).  Any ideas what's causing this?

Any help would be greatly appreciated, thanks!
kurt
Ohh_avatar
Posts: 17
 		Posted 2012-08-09 16:07:26 UTC Reply

I think that's because the Arduino Pro Mini uses pin 13 to talk to the USB Host Shield Mini. Here's a pinout of the Arduino pins in the USB to Bluetooth Adapter:

  • pins a0-a1 are used to send software serial commands to the bt module (a0 is arduino tx, a1 is arduino rx)
  • pin 2 connects the usb device's d+ and d- pins to the computer when held high
  • pin 3 connects the device's d+ and d- pins to the usb host shield when held high
  • pin 4 is the pushbutton. low=pressed. high=unpressed
  • pin 5 enables power to the usb device. high=on
  • pins 7-13 are used by the usb host shield to talk to the arduino pro mini (7=max_rst, 8=gpx, 9=int, 10=ss, 11=mosi, 12=miso, 13=sclk)

If you want to use an LED as an indicator, you'll have to use another pin.
daniel
Screen%20shot%202011-02-01%20at%201.43.43%20am
Posts: 4
 		Posted 2012-08-10 18:48:17 UTC Reply

That explains it, thanks!

+ Forums > Help and Questions > USB host shield and arduino LED flicker

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