stripes
Member
Registered: Sep 1999
Location: VA, USA
Posts: 27 |
Just because USB cradles are "better" doesn't mean they cost more to make.
The serial pins on the Palm, and I assume Visor run at non-standard and wildly varying power levels, as one would expect from a budget designed 2 AAA powered device designed only to talk to it's own cradle. This level has to be converted to the +/- 5V swing that is the PC's worlds standard (25V is the actual RS-232 standard, and I think 3V actually does the trick in the real world, most of the time, and I think the palm is more like about 1V to under 1V).
USB on the other hand provides signaling power, even an "unpowered" USB device still gets enough power from the USB line to drive it's output.
That means the serial cradle needs a few parts, needs them sodered, needs them assembled. The USB cradle could be just wired and a switch (I think the hot sync button shorts two leads on the Visor, if it actually signals stuff on USB then I lose the USB device is more complex).
Of corse how much something costs to make isn't the only factor in how much people get charged to buy it...
|