Pro Trinket Sketch Loading Issue (Pulsing Light never times

[rodbray]

Hello,
When I plug my Pro Trinket into the USB cable the boot loader pulsing light never times out. If I push the reset button it hesitates and then starts pulsing as expected but again never stops. If I try and upload a sketch I get the dreaded error: avrdude: Error: Could not find USBtiny device (0x1781/0xc9f) Error. I have tried two computers (one WIn10 and one Win 8.1) and 3 different USB cables. I can see the Trinket in device manager and am using the most recent IDE from Arduino(1.6.5). I also updated the files and avrdude as described on the website to get the boards supported in the IDE. One other thing I have noticed as well. When I hook the Pro Trinket to power with the USB cable unplugged, the green light comes on and the red led flashes in sequence of three quick flashes and then pauses and starts over keeping this up indefinitely.

Thanks for any help you can provide,
-Rod

[hiduino]

The pulsing led is normal when there is no sketch loaded. The bootloader will continually re-run until you load in your fist sketch. The problem is your computers are not seeing the Pro Trinket. Try a USB 2.0 port, you may need to get an external USB 2.0 Hub to get this to work.

[rodbray]

Same experience with a USB 2.o Hub. Windows sees the device, named USBtiny, but will not load any sketch. Still getting the
avrdude: Error: Could not find USBtiny device (0x1781/0xc9f)

[hiduino]

This might be obvious but did you install the USBtiny drivers? https://learn.adafruit.com/introducing- ... or-windows

[rodbray]

I did...still no joy