Contactless audio adapter, and methods
A contactless, electromagnetic (EM) replacement for cabled Standards-based interfaces (such as USB, I2S) which handles data transfer requirements associated with the Standard, and capable of measuring and replicating relevant physical conditions on data lines so as to function compatibly and transparently with the Standard. A contactless link between devices having transceivers. A non-conducting housing enclosing the devices. A dielectric coupler facilitating communication between communications chips. Conductive paths or an inductive link providing power between devices. An audio adapter communicates over a contactless link with a source device, and via a physical link with a destination device such as a conventional headset. Power may be provided to the adapter from the source device, and by the adapter to the destination device.
1. A first device for establishing contactless USB communications with a second device, the first device comprising:
a USB controller; and
a contactless communications unit (CCU) comprising:
a plurality of contacts coupled to the USB controller;
a transducer; and
circuitry coupled to the contacts and the transducer and operative to:
determine a USB electrical condition existing on at least one of the contacts; and
contactlessly transmit a contactless signal indicative of the determined USB electrical condition via the transducer to a recipient CCU in the second device, wherein the contactless signal indicative of the determined USB electrical condition enables the recipient CCU to replicate the same USB electrical condition on at least one of its contacts so that link establishment conditions required by a USB controller associated with the second device are satisfied even though a contactless link exists between the CCU and the recipient CCU.
2. The first device of claim 1 , wherein the determined electrical condition is part of a negotiation sequence between the USB controller and another USB controller coupled to the recipient CCU in the second device for establishing a physical communications link, and wherein the contactlessly transmitted contactless signal indicative of the determined USB electrical condition is transmitted within fixed timing constraints that govern the negotiation sequence for establishing the physical communications link between the USB controllers.
3. The first device of claim 1 , wherein the USB electrical condition comprises enumeration conditions required for establishing a link pursuant to a USB protocol, wherein the link is part of a contactless USB connection between the first and second devices.
4. The first device of claim 1 , wherein the USB electrical condition comprises power state information required for establishing a link pursuant to a USB protocol, wherein the link is part of a contactless USB connection between the first and second devices.
5. The first device of claim 1 , wherein the USB electrical condition comprises termination resistance.
6. The first device of claim 1 , wherein the USB electrical condition comprises line voltage.
7. The first device of claim 1 , wherein the USB electrical condition comprises at least one of drive strength, status, configuration, and drive type.
8. A first device for establishing contactless USB communications with a second device, the first device comprising:
a first USB controller; and
a contactless communication unit (CCU) comprising:
a plurality of contacts coupled to the USB controller;
a transducer; and
circuitry coupled to the contacts and the transducer and operative to:
receive a contactless signal indicative of USB electrical signaling conditions provided by a second USB controller in the second device for establishing the physical communications link;
replicate the USB electrical signaling conditions based on the received contactless signal indicative of USB electrical signaling conditions provided by the second USB controller; and
provide the replicated signaling conditions on at least one of the contacts so that the first USB controller is provided with the USB electrical signaling conditions provided by the second USB controller such that the requirements for establishing a physical communications link between the first and second USB controllers are satisfied even though they are not connected by a physical interface.
9. The first device of claim 8 , wherein the received USB electrical condition is part of a negotiation sequence between the first and second USB controllers for establishing a physical communications link, and wherein the contactlessly transmitted contactless signal indicative of the determined USB electrical condition is transmitted within fixed timing constraints that govern the negotiation sequence for establishing the physical communications link between the USB controllers.
10. The first device of claim 8 , wherein the USB electrical condition comprises enumeration conditions required for establishing a link pursuant to a USB protocol, wherein the link is part of a contactless USB connection between the first and second devices.
11. The first device of claim 8 , wherein the USB electrical condition comprises power state information required for establishing a link pursuant to a USB protocol, wherein the link is part of a contactless USB connection between the first and second devices.
12. The first device of claim 8 , wherein the USB electrical condition comprises termination resistance.
13. The first device of claim 8 , wherein the USB electrical condition comprises line voltage.
14. The first device of claim 8 , wherein the USB electrical condition comprises at least one of drive strength, status, configuration, and drive type.
15. A method for emulating a physical USB connection between first and second devices that communicate data via a contactless communications coupling, the method implemented in the first device comprising a transceiver and a USB controller, the method comprising:
determining an electrical condition of the USB controller, which expects the electrical condition of at least one signal line to comply with parameters specified for a USB protocol designed for communicating data over a physical link; and
contactlessly transmitting an electromagnetic (EM) signal indicative of the determined electrical condition, wherein the EM signal indicative of the determined electrical condition enables the second device to modify itself to comply with parameters specified for the USB protocol.
16. The method of claim 15 , wherein the parameters specified for the USB protocol comprise speed characteristics and termination characteristics.
17. The method of claim 15 , wherein the determined electrical condition is an electrical characteristic imparted on the at least one signal line by the USB controller that must be replicated by a transceiver associated with the second device so that a USB controller coupled to the transceiver of the second device receives the replicated electrical characteristic.
18. The method of claim 15 , further comprising:
receiving a sequence of electrical characteristics from the USB controller on the at least one signal line;
wherein the determining comprises determining the electrical condition of each received electrical characteristic; and
wherein the contactlessly transmitting comprises contactlessly transmitting an electromagnetic (EM) signal indicative of each received electrical characteristic.