# US 2021/0344140 A1 · Circuits and methods for wearable device charging and wired control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0344140 A1 - Document ID: US20210344140A1 - Status: Published application - Kind: A1 - Application number: 17/376,507 - Filed: 2021-07-15 - Published: 2021-11-04 - Earliest claimed: 2016-10-12 - Assignees: Snap Inc. - Applicants: Snap Inc. - Inventors: Russell Douglas Patton; Jonathan M. Rodriguez, II; Stephen Andrew Steger - Web page: https://patentgrep.com/patent/US20210344140A1 ## CPC - H02J 7/68: using circuits for correcting or protecting against reverse-polarity - G02C 5/146: {having special front end} - G02C 11/10: {Electronic devices other than hearing aids} - H01R 13/6205: {Two-part coupling devices held in engagement by a magnet} - H02J 7/04: Regulation of charging current or voltage - H02J 7/345: {using capacitors as storage or buffering devices} - H02J 7/751: {concerning the insertion or the connection of the batteries} - H02J 7/865: {Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence)} - H03K 19/018557: {Coupling arrangements; Impedance matching circuits} - H04B 3/56: Circuits for coupling, blocking, or by-passing of signals - H10D 89/811: {using FETs as protective elements} - G02C 1/00: Assemblies of lenses with bridges or browbars - G02C 11/00: Non-optical adjuncts; Attachment thereof (G02C7/16 takes precedence) - H02J 7/00: Circuit arrangements for charging or discharging batteries or for supplying loads from batteries - H02J 7/42: with electronic devices having internal batteries, e.g. mobile phones - H02J 7/61: against overcharge - H02J 7/63: against overdischarge - H04B 3/548: {the power on the line being DC (arrangements for feeding power H04L12/10; extracting feeding power from signals H04L25/02)} - H04B 2203/5454: Adapter and plugs - H04B 2203/547: via DC power distribution - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - G02C: SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES (trial frames for testing the eyes A61B3/04; goggles or eyeshields not having the same features as spectacles A61F9/00) - H01R: ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - H04B: TRANSMISSION - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract Methods and devices for wired charging and communication with a wearable device are described. In one embodiment, a symmetrical contact interface comprises a first contact pad and a second contact pad, and particular wired circuitry is coupled to the first and second contact pad to enable charging as well as receive and transmit communications via the contact pads as part of various device states. ## Claims ### Claim 1 An apparatus for controlling a wearable device, the apparatus comprising: a first n-type field effect transistor (NFET) having a source connected to a communication path to be coupled with communication circuitry of the wearable device, a gate connected to a control input configured for selecting between a charging mode and a communication mode of the apparatus, and a drain connected to a data input path; and a second NFET having a gate connected to the control input, a source connected to a ground, and a drain connected to a ground path for the data input path. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the data input path is a data input/output path for the apparatus to send data signals to the wearable device and for the apparatus to receive data signals from the wearable device. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein a power supply is connected to the drain of the first NFET. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein the wearable device comprises the apparatus. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein the data input path is connected with a data input/output path of a host device. ### Claim 6 (depends on 5) The apparatus of claim 5 wherein the host device comprises the apparatus. ### Claim 7 (depends on 1) The apparatus of claim 1 wherein a high voltage of the control input selects the communication mode. ### Claim 8 (depends on 1) The apparatus of claim 1 further comprising a symmetrical contact interface comprising a first contact pad and a second contact pad, wherein the first contact pad is connected to the first NFET and the second contact pad is connected to the second NFET. ### Claim 9 (depends on 1) The apparatus of claim 1 further comprising: a first p-type field effect transistor (PFET) having a source connected to a wearable device voltage terminal, a gate connected to a second input path, and a drain connected to a first input path; a second PFET having a source connected to the wearable device voltage terminal, a gate connected to the first input path, and a drain connected to the second input path; a third NFET having a source connected to a wearable device ground, a gate connected to the second input path, and a drain connected to the first input path; and a fourth NFET having a source connected to the wearable device ground, a gate connected to the first input path, and a fourth drain connected to the second input path, wherein the drain of the first NFET is connected between the first PFET and the third NFET. ### Claim 10 An apparatus for controlling a wearable device, the apparatus comprising: a first p-type field effect transistor (PFET) having a drain connected to a communication path to be coupled with communication circuitry of the wearable device, a gate connected to a control input configured for selecting between a charging mode and a communication mode of the apparatus, and a source connected to a data input path; and a second PFET having a gate connected to the control input, a drain connected to a ground, and a source connected to a ground path for the data input path. ### Claim 11 (depends on 10) The apparatus of claim 10 wherein the data input path is a data input/output path for the apparatus to send data signals to the wearable device and for the apparatus to receive data signals from the wearable device. ### Claim 12 (depends on 10) The apparatus of claim 10 wherein a power supply is connected to the source of the first PFET. ### Claim 13 (depends on 10) The apparatus of claim 10 wherein the wearable device comprises the apparatus. ### Claim 14 (depends on 10) The apparatus of claim 10 wherein the data input path is connected with a data input/output path of a host device. ### Claim 15 (depends on 14) The apparatus of claim 14 wherein the host device comprises the apparatus. ### Claim 16 (depends on 10) The apparatus of claim 10 further comprising a symmetrical contact interface comprising a first contact pad and a second contact pad, wherein the first contact pad is connected to the first PFET and the second contact pad is connected to the second PFET. ### Claim 17 (depends on 10) The apparatus of claim 10 wherein a high voltage of the control input selects the communication mode. ### Claim 18 A system for wired control comprising: a wearable device comprising a symmetrical contact interface comprising a first contact pad and a second contact pad; and means for receiving control data via the first contact pad and the second contact pad. ### Claim 19 (depends on 18) The system of claim 18 further comprising: a first charge cable comprising a cable head, the cable head comprising a second symmetrical interface comprising a first pogo pin and a second pogo pin configured to interface with the first contact pad and the second contact pad. ### Claim 20 (depends on 18) The system of claim 18 wherein the wearable device comprises glasses, wherein the symmetrical contact interface is further disposed in a temple portion of the glasses front end proximate to a first hinge, such that a first arm coupled to the temple portion via the first hinge covers the symmetrical contact interface of the first surface when the first arm is in an open position, and the first arm exposes the symmetrical contact interface of the first surface when the first arm is in a closed position, and wherein the cable head is configured to interface with the symmetrical contact interface when the first arm is in the closed position.