[BRLTTY] BRLTTY, HT Active Braille on Raspberry pi 2, USB

[Dave Mielke]

[quoted lines by Lars Bjørndal on 2016/04/26 at 10:43 +0200]

>I've tried the device and the cable with another computer, and had no
>problem. The USB port on the rpi is working ok for other devices, like
>wifi/bluetooth controllers and wired keyboard. Right now, I'm using a
>Handy Tech Modular Evolution 88, and that too works fine with the rpi.

Yes, all of that seems to indicate that the ports, cable, device, and rpi are 
all okay.

>Could it be a problem with displays that consume power from the USB
>port? The Active Braille reports it uses USB power when connected. With an rpi and a
>charging bank, there may be limitations, maybe? I don't know.

Perhaps. Can the HT AB be configured to not request power from the port?

You're getting three errors:

   ETIMEOUT (for an output operation not being confirmed within one second)
   EPROTO (USB protocol error)
   ENODEV (the USB device has disappeared)

I suppose it's possible, if right near a limit, that the device is switching 
between getting and not getting power.

Are other devices drawing power from the rpi's USB? If so, what happens if you 
disconnect them?

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Dave Mielke           | 2213 Fox Crescent | The Bible is the very Word of God.
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