I don't quite grasp the following:

When I put the PDA in the cradle, which is connected to the home adaptor,
nothing happens. Only the loading led starts flashing.
When I connect the PDA to the car adaptor (ignition on), the PDA switches on
automatically.

How come, different behaviour?



--
regards,

|\ /|
| \/ |@rk
\../
\/os

At 12 Aug 2009 16:10:29 +0200 Linea Recta wrote:
> I don't quite grasp the following:
>
> When I put the PDA in the cradle, which is connected to the home adaptor,

> nothing happens. Only the loading led starts flashing.
> When I connect the PDA to the car adaptor (ignition on), the PDA
> switches on automatically.
>
> How come, different behaviour?


Different wiring connected to different pins on the device. You didn't
tell us what device you have, but on my HTC devices, plugging in an
'official' HTC AC charger leaves the device powered off (presuming it was
off when I plugged it in), but any generic mini-USB charger, like my car
charger wakes up the device.

I suspect an extra (or missing) pin on the HTC charger "tells" the device
it's only connected to the charger, but all other USB connections wake up
the device to detemine whether or not there's a PC on the other end to
sync with.

"Todd Allcock" <elecconnec@aNOoSPAMl.com> schreef in bericht
news:330667516620090812155856elecconnec@aNOoSPAMl. com...
> At 12 Aug 2009 16:10:29 +0200 Linea Recta wrote:
>> I don't quite grasp the following:
>>
>> When I put the PDA in the cradle, which is connected to the home adaptor,
>
>> nothing happens. Only the loading led starts flashing.
>> When I connect the PDA to the car adaptor (ignition on), the PDA
>> switches on automatically.
>>
>> How come, different behaviour?
>
>
> Different wiring connected to different pins on the device. You didn't
> tell us what device you have, but on my HTC devices, plugging in an
> 'official' HTC AC charger leaves the device powered off (presuming it was
> off when I plugged it in), but any generic mini-USB charger, like my car
> charger wakes up the device.
>
> I suspect an extra (or missing) pin on the HTC charger "tells" the device
> it's only connected to the charger, but all other USB connections wake up
> the device to detemine whether or not there's a PC on the other end to
> sync with.



In my case it is an Asus Mypal A730W.
Thanks for your input. It seems there's a lot more to it than just a 5V DC
power line...




--
regards,

|\ /|
| \/ |@rk
\../
\/os

>> It seems there's a lot more to it than just a 5V DC
power line... <<

many varients... plus some mfg's put circuits within the power cords and
cradles that complicate things even more.

In USB's simplest form the "fifth" pin is used for charging, but I have
seen other four pin connections that apparently make decisions based on
comm's on the usb rx/tx lines to go into different states, including a
couple of devices that refuse to take a charge from a 5v usb power
source with the rx/tx pins dead.

Beverly Howard