Method and apparatus for transfering data between USB client devices by toggling a USB V
A method and apparatus for transferring data from a first electronic device to a second electronic device, both first and second electronic devices having Universal Serial Bus (USB) client interfaces, the method comprising the steps: connecting the two electronic devices with a USB cable; toggling the voltage on a V BUS line of the USB cable between logic high voltage and no voltage at the first electronic device; detecting toggles of the V BUS line at the second electronic device; and interpreting the toggles detected in the detecting step as data.
1. A method for transferring data from a first electronic device to a second electronic device, both first and second electronic devices having Universal Serial Bus (USB) client interfaces, the method comprising the steps:
connecting the two electronic devices with a USB cable;
toggling in accordance with a pattern the voltage on a V BUS line of the USB cable between logic high voltage and no voltage at the first electronic device;
detecting toggles of the V BUS line at the second electronic device; and
interpreting the pattern of toggles detected in said detecting step as data.
2. The method of claim 1 , wherein said interpreting step counts the number of toggles.
3. The method of claim 1 , wherein said interpreting step counts the number of toggles in a predetermined time period.
4. The method of claim 1 , wherein said interpreting step can transfer bits by providing a high voltage to represent a binary one and no voltage to represent a binary zero in a specific time slot.
5. The method of claim 1 , wherein said detecting step includes:
triggering an interrupt when a toggle occurs; and
incrementing a counter upon said triggering.
6. The method of claim 1 , further comprising a handshaking routine to indicate a start of data transmission.
7. The method of claim 1 , wherein the V BUS line is toggled at rate four toggles per second or greater.
8. The method of claim 1 , wherein the amount of data being transferred is 512 bits or less.
9. A USB client apparatus adapted to communicate with a second USB client apparatus, the USB client apparatus comprising:
a USB port; and
a software module for toggling in accordance with a pattern a V BUS line on said USB port, the software module configured to interact with a USB interlace for said USB port.
10. The USB client apparatus of claim 9 , wherein said apparatus is a mobile data device.
11. The USB client apparatus of claim 9 , wherein said apparatus is a peripheral for a mobile data device.
12. The USB client apparatus of claim 11 , wherein said apparatus is a Bluetooth smart card reader.
13. A USB client apparatus adapted to communicate with a second USB client apparatus, the USB client apparatus comprising:
a USB port;
means for detecting a toggling pattern of a V BUS line on said USB port; and
means for interpreting said toggling pattern into data content.
14. The USB client apparatus of claim 13 , wherein said means for interpreting is adapted to count the number of toggles.
15. The USB client apparatus of claim 13 , wherein means for interpreting is adapted to count the number of toggles in a predetermined time period.
16. The USB client apparatus of claim 13 , wherein said means for interpreting is adapted to recognize bits by understand a high voltage to represent a binary one and no voltage to represent a binary zero in a specific time slot.
17. The USB client apparatus of claim 13 , wherein said means for detecting includes:
means for triggering an interrupt when a toggle occurs; and
means for incrementing a counter upon said triggering.
18. The USB client apparatus of claim 13 , further comprising a module adapted for handshaking with the second USB client apparatus at a start of data transmission.
19. The USB client apparatus of claim 13 , wherein the apparatus is a mobile data device.