ALl the specs for USB show and spec ONE load period. If you only break ground or power you would still have
two loads on the data - and the data +. This will increase the capacitive load and will make the usb
connection very unreliable. Power and ground can stay connected as they are static levels.
If you look at the top waveform (blue) you will see the square wave data that is being transmitted:
But the bottom waveform is the same square wave with an additional load being added to the circuit.
As the data rate increases the data high goes away before the data can even charge through the circuit
giving you read errors.
That is why you have to switch the data lines so they only see one load
But I have been doing some researching and we are thinking that even though the choto shot camera is hooked
up to the usb port, it is not true usb. I am checking for you but Jean over at pspdev.org has put forth the
theory that the camera is not hooked to the data - or data + lines. There is an additional single line
on the usb connector that is used for vendor id functions. I also think that Sony is using this additional
line as a high speed serial port.
If you can give me a day or two to check this out, I should have an answer for you. Then you would only need
a single double pole switch to change this single line to and from the camera (also the usb GPS )
This may be the reason that people are having problems moving the camera inside.
If we look at the mini usb connector we see 5 pins not 4
The pins are defined as:
The one marked X is vendor specific, that is the one we think is used for the ChotoShot Camera
If this turns out to be true then we will have to switch power and this line to the camera.
I will let you know.
