Problem with Kindle branded charger


5 posts
by anotherdave » Mon Aug 06, 2012 9:19 am
Hi,

I'm using a standard UK Kindle charger (specified as Input 100-240V, ~ 0.15A; Output: 5.0V, 0.85A), but I think I'm getting low power from it — the Pi boots to the raspi-config screen, but I can't interact with it: getting no response to key presses. I'm also seeing a
Code: Select all
cannot reset port 2
error during boot, though couldn't catch full details because of the speed of the logging.

I've done a quick search of the forums, but everyone seems to be saying that the Kindle charger is working fine for them. Is there anything anyone would recommend in debugging this? For low power errors, people have suggested a powered-hub though thought I'd be OK with the above charger & just a standard Apple keyboard?

Any suggestions very appreciated! :)

Best,
Dave
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by Jim JKla » Mon Aug 06, 2012 9:28 am
See if you can get your hands on a cheap keyboard standard wired USB or a PS2 one with a USB converter plug there must be millions out there.

Another alternative is start as a Blind login there is Noob help on the wiki

http://elinux.org/RPi_A_Method_for_ssh_blind_login

for this and it will allow you to test your RPi without a keyboard or mouse.

There is an outside posibility that your keyboard is pulling down the power. ;)
Noob is not derogatory the noob is just the lower end of the noob--geek spectrum being a noob is just your first step towards being an uber-geek ;)

If you find a solution please post it in the wiki the forum dies too quick
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by redhawk » Mon Aug 06, 2012 10:38 am
I had a Motorola charger that was rated 5v @ 850ma it was rubbish for the PI because as soon as it was loaded the output voltage drops which just goes to show you can't always trust branded products.
To check the suitability of your power supply you must attach some devices to the USB port to create a load i.e. USB fan, PS/2 HID adapter, sound dongle or wifi adapter.
If the voltage between TP1 and TP2 drops below 4.8volts I would consider changing the power supply.

Richard S.
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by anotherdave » Mon Aug 06, 2012 11:00 am
Hi Jim, Richard,

thanks a million for getting back so quick. It was indeed the keyboard! I managed to shell in with the link you provided Jim and have the box up and running. I must try and find a more basic keyboard… Don't want to buy one, I know I must have one somewhere! :)

Richard, thanks for the extra info. I've no real proper equipment at the moment for checking voltages. Probably something I should pick up alright though, would be handy to have for Arduino hacking also.

Thanks again guys! :)

Best,
Dave
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by redhawk » Mon Aug 06, 2012 11:49 am
If you have some spare PS/2 keyboards knocking about then this adapter may prove useful http://www.amazon.co.uk/NEWLink-USB-Key ... 001FB6WMS/ however a lot would depend on whether your power supply can still hold the correct voltage.

Richard S.
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