Reversible connector for accessory devices

Abstract

Reversible connectors for accessory devices are described. In one or more implementations, a connector cable for an accessory of a host computing device is configured such that a head of the connector cable may be plugged into a corresponding port of the host in either orientation (straight or reverse). The host computing device is configured to sample signals associated with allocated pins of the connector to detect connection of the connector to an accessory port and to ascertain an orientation of the connector. A combination of high and low values of signals conveyed via these allocated pins upon insertion of the connector may be used by a controller of the host to distinguish between different types of devices and to resolve the orientation of the connector cable. A switching mechanism of the host computing device may then be configured to automatically route signals accordingly.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different instances in the description and the figures may indicate similar or identical items. Entities represented in the figures may be indicative of one or more entities and thus reference may be made interchangeably to single or plural forms of the entities in the discussion.

FIG. 1 is an illustration of an environment in an example implementation that is operable to employ the techniques described herein.

FIG. 2 depicts an example computing device and accessory device of FIG. 1 in greater detail.

FIG. 3 depicts an example scenario for reversible connection of an accessory to an accessory port in accordance with one or more implementations.

FIG. 4 depicts an example representation of an arrangement of pins for a connector in accordance with one or more implementations.

FIG. 5 depicts an example procedure in accordance with one or more implementations.

FIG. 6 depicts another example procedure in accordance with one or more implementations.

FIG. 7 illustrates an example system including various components of an example device that can be implemented as any type of computing device to implement embodiments of the techniques described herein.

DETAILED DESCRIPTION

Overview

Today, mobile computing devices such as laptops and tablets may be configured to support and connect to a variety of types of accessory devices by way of universal serial bus (USB) or other communication techniques. However, traditional connectors, ports, and connector cables for accessories are designed for connection in a single orientation. Accordingly, users may often attempt to make connections in the wrong way, which is not only frustrating for the user, but may also result in wear and/or damage to the connectors, ports, and connector cords.

Reversible connector techniques for accessory devices are described. In one or more implementations, a connector cable for an accessory of a host computing device is configured such that a head of the connector cable may be plugged into a corresponding port of the host in either orientation (straight or reverse). The host computing device is configured to sample signals associated with allocated pins of the connector to detect connection of the connector to an accessory port and to ascertain an orientation of the connector. A switching mechanism of the host computing device may then be configured to automatically route signals according to the orientation. In one approach, a pair of “detection” pins of the connector is dedicated for hot plug detection. A combination of high and low logic states that is conveyed via these two detection pins upon insertion of the connector may be used by a controller of the host to distinguish between different types of devices (e.g., two wire and one wire devices) and to resolve the orientation of the connector cable. Lines associated with the two detection pins may be sampled together (e.g., in parallel or in sequence) and values for obtained for the two line may be combined together to derive a combined logic state indicative of the device type and/or connector orientation. The controller may then operate to set-up signal routing according to the type of device and orientation. In order to do so, the controller may be configured to direct positions for switches and multiplexers of the host and/or the connected accessory to effectuate straight or reverse signal paths as appropriate.

In the following discussion, an example environment and devices are first described that may employ the techniques described herein. Example details and procedures are then described which may be performed in the example environment and by the devices as well as in other environments and by other devices. Consequently, implementation of the example details and procedures is not limited to the example environment/devices and the example environment/devices are not limited to the example details and procedures.

Example Operating Environment

FIG. 1 is an illustration of an environment 100 in an example implementation that is operable to employ the techniques described herein. The illustrated environment 100 includes an example of a host computing device 102 that is physically and communicatively coupled to an accessory device 104 via an interface 106. The host computing device 102 may be configured in a variety of ways. For example, the computing device 102 may be configured for mobile use, such as a mobile phone, a tablet computer as illustrated, and so on. Thus, the host computing device 102 may range from full resource devices with substantial memory and processor resources to a low-resource device with limited memory and/or processing resources. The host computing device 102 may also relate to software that causes the host computing device 102 to perform one or more operations.

The host computing device 102, for instance, is illustrated as including an input/output module 108. The input/output module 108 is representative of functionality relating to processing of inputs and rendering outputs of the host computing device 102. A variety of different inputs may be processed by the input/output module 108, such as inputs relating to functions that correspond to keys of the input device, keys of a virtual keyboard displayed by the display device 110 to identify gestures and cause operations to be performed that correspond to the gestures that may be recognized through the accessory device 104 and/or touchscreen functionality of the display device 110, and so forth. Thus, the input/output module 108 may support a variety of different input techniques by recognizing and leveraging a division between types of inputs including key presses, gestures, and so on.

Various configurations for an accessory device 104 are also contemplated, such as a keyboard, game controller, configuration to mimic a musical instrument, a power adapter, a docking station, a USB hub, an external battery, combinations of these configurations, and so forth. Thus, the accessory device 104 may assume a variety of different configurations to support a variety of different functionality. Different accessory devices may be removably connected to the computing device at different times.

As previously described, the accessory device 104 is physically and communicatively coupled to the host computing device 102 in this example through an interface 106. Various types of interfaces 106 and connectors are also contemplated such as uses of a flexible hinge, magnetic coupling devices, integrated communication ports and communication contacts, mechanical coupling protrusions, slots, and/or indentions, individually or in combination to form different types of interfaces 106. In one example, the interface 106 may represent an accessory port (e.g., communication port) configured to enable connection to accessory devices via a corresponding connector and/or connector cord. In accordance with techniques discussed above and below, the accessory port and corresponding connector are designed to enable reversible connection of the connector to the port. In at least some implementations, the interface 106 is configured to enable communications for authentication and control of the accessory device 104 as described herein. For example, the computing device 102 may receive credentials (e.g., data indicative of an identity of an accessory), signals, and other data regarding capabilities of the accessory device through the interface responsive to detecting the presence/attachment of the accessory device 104. The interface may also provide a power coupling for exchange of power and communication of messages to implement and update power management and control functions as described above and below.

As further illustrated in FIG. 1 the computing device 102 may include a power controller 112 configured to implement aspects of power management contract techniques described herein. In particular, the power controller 112 represents functionality to perform various operations for power management including handling settings for power management based on accessory identities, facilitating exchange of control messages between the host and accessories, management of different power sources and switching between the sources, implementing a defined and/or selected power management scheme, managing battery life, and so forth. The power controller 112 may further facilitate connections and communications with a power adapter 114 (also referred to herein as a power supply unit (PSU)) configured to supply power to the device via a suitable external power source 116, such as a wall socket, external battery, power supply unit, or other of power source. The power controller 112 may also be operable to supply power to accessory devices in appropriate circumstances. In other words, the power controller 112 may manage power operations jointly for a host computing device and authorized accessory devices including power exchange between the host computing device and an accessory device.

The power controller 112 may be implemented in hardware, software, firmware and/or combinations thereof. By way of example and not limitation, the computing device 102 may include a microcontroller or other suitable hardware logic device configured to implement various functionally that is described herein in relation to power controller 112. The power controller 112 may therefore represent firmware or logic associated with a suitable hardware logic device. In addition or alternatively, the power controller 112 may be implemented by way of a processing system of the device and one or more program modules that are executable/operable via the processing system.

The power adapter 114 may be configured to selectively operate in multiple modes and supply multiple power levels to the computing device. The level of power supplied at a particular time may be based upon input, notifications, or other suitable feedback configured and sent to the power adapter 114 by the power controller 112 to cause the power adapter 114 to supply a corresponding level of power. Depending upon a power exchange state, the power adapter 114, when connected to the computing device, may charge a battery associated with one or both of the host and accessory, supply power to support operations of one or both the host and accessory, and otherwise supply power from external power sources 116 for joint charging and operation of the host and accessory in various combinations. A power scheme implemented via the power controller 112 may be configured to control flow of power between system components (e.g., host, accessory, and adapter) in dependence upon accessory identity, power exchange conditions, power source availability, and so forth. Further details regarding operation of the power controller 112 and the power adapter 114 to implement power management contracts for accessory devices can be found in the following discussion.

FIG. 2 depicts generally at 200 an example host computing device 102 and accessory device 104 in greater detail. In FIG. 2, the host computing device 102 is depicted as having a power controller 112 is illustrated as being provided by one or more microcontroller(s) 202, also referred to as micro-processing unit(s) (μP). The computing device 104 further includes an associated power supply 204, such as one or more internal batteries. The accessory device 104 may also include one or more microcontroller(s) 206 and a respective power supply 208. The power supply 208 may be configured as one or more batteries that are internal to the accessory device 104 (e.g., an accessory battery) and may therefore be considered external batteries with respect to the host computing device 102.

The example microcontrollers (μPs) represent hardware devices/systems that are designed to perform a predefined set of designated tasks. Microcontrollers may represent respective on-chip systems/circuits having self-contained resources such as processing components, I/O devices/peripherals, various types of memory (ROM, RAM, Flash, EEPROM), programmable logic, and so forth. Different microcontrollers may be configured to implement embedded applications/functionality that are implemented at least partially in hardware and perform corresponding tasks. In particular, the example microcontrollers 202, 206 enable performance of tasks for device authentication and power management outside of operation of a general purpose processing system and other applications/components of the computing device or accessory device. Generally, power consumption of the microcontrollers is low in comparison with operating a general purpose processing system for a device.

Accordingly, components implemented via microcontrollers may operate using relatively low power, independently of operating a “primary” processing system of a host computing device, and/or without booting/executing an operating system or using other device components and applications. In other words, the microcontrollers may operate to perform some power management tasks in a low power mode without having to operate or supply power to the processing system and other device components (e.g., device memory, network interface, display device, etc.) and/or without completely starting-up or waking-up the computing device.

The host computing device 202 may be connectable to different accessory devices via an accessory port 210. The accessory port 210 is representative of functionality to achieve a physical and communicative coupling between the host computing device and various accessories. For example, a connector 211 corresponding to the accessory port 210 may be employed to connect accessories to the host computing and enable exchange of control signals, data, and power. In the depicted example, the connector 211 is illustrated as a connector cord that may be removably inserted into a corresponding port associated with the accessory interface 210, although other types of connections are also contemplated, such as the flexible hinge discussed in relation to FIG. 1, connections to a docking station discussed in relation to the following figure, and/or another suitable interfaces and connector combinations. In accordance with techniques described herein, the connector 211 and corresponding ports may be configured to support reversible connection/insertion of the connector/port combination.

As represented in FIG. 2, power exchange may occur between the power supply 204 of the host and the power supply 208 of the accessory in accordance with techniques described above and below. In some implementations, power exchange may also occur with an external power source 116 configured as an external battery via a power adapter 114 as represented in FIG. 1. In other words, three-way power exchange may occur between batteries/power supplies corresponding to the host, an accessory connected via the accessory interface, and an external power source. Generally, power exchange between the host and one or more connected devices (adapters/accessories/peripherals) may occur back and forth (e.g., bi-directionally) from the host to one or more of the devices, from one or more of the devices to the host, and/or directly between connected devices (e.g., device to device) through the host.

Thus, power exchange may occur via the accessory port 210 in some scenarios. Power supplied to the host computing device may be used to operate the host (e.g., service the system load) and/or to maintain a charge level of the power supply 204 (e.g., internal battery). Additionally, power supplied to the host may be supplied directly or indirectly to the accessory device 104 to support operations and/or charge the power supply 208 (e.g., external battery). Moreover, power may be distributed from the host computing device 102 and/or the accessory device 104 to one or more peripherals 212 that may be connected directly to the host computing device and/or connected to the system through the accessory device 104 as represented in FIG. 2. For example, in one or more implementations an accessory device may be configured to provide functionality of a peripheral device hub, such as a hub that provides multiple universal serial bus (USB) ports and/or other types of connection ports to which a variety of peripherals 212 may be connected. The peripherals 212 may include various devices, such as a peripheral display device, a printer, a scanner, audio devices, a camera, a storage device, or a network adapter, to name a few examples.

It should be noted that the host computing device 102 and accessory device 104 may both be configured to employ external power sources 116, such as through the use of respective power adapters 114 connected to a wall socket or another source. Power supplied directly to the accessory device 104 via a respective power adapter 114 may be used, shared, and/or exchanged between the host and accessory in a manner comparable to power that is supplied directly to the host computing device 102.

The host computing device may be further configured to implement a power scheme 214 and a security module 216 in various ways. In the illustrated example, the power scheme 214 is depicted as being implemented via the power controller 112. In this example, the power scheme 214 is configured as firmware associated with the host computing device 102. For example, the power scheme 214 may represent firmware associated with a microcontroller 202, power controller 112, or other suitable hardware logic device. Alternatively, the power scheme 214 may be implemented as a standalone module using any suitable combination of hardware, software, firmware, and/or logic devices.

The power scheme 214 represents functionality to implement power management contract techniques described above and below as well as other power management functions. In particular, the power scheme 214 may be configured to jointly manage power flow between a power adapter 114, host computing device 102, and accessory device 104. By way of example and not limitation, this may include controlling power flow to selectively charge batteries associated with the components; exchange power between the batteries, processing systems, and components; supply power to service the system load for the host and accessory; and so forth. In order to do so, the power scheme 214 may provide functionality to establish, enforce, and update power management contracts 218 between various components of the system. This functionality may include support for sending and receiving messages regarding power management between system components that may be configured in a variety of ways. For example, the messages may be configured as pulsed signal patterns that are recognizable by respective controllers of the host and accessory. Various suitable messaging protocols and corresponding message formats are also contemplated, such as using inter-integrated circuit (I²C) protocol, serial peripheral interface (SPI), universal asynchronous receiver/transmitter (UART) messaging, packet based communications, and object based messages, to name a few examples. Further, wireless messaging protocols such as near-field communication, Bluetooth, WiFi, RF protocols used in RFID, or cellular telecommunication protocols may be used.

The power management contracts 218 are configured to define operating constraints for power management including but not limited to specifying power exchange direction and current limits for different devices and scenarios. Moreover, the settings for power management contracts 218 may be modified in real-time based on conditions observed by the host or accessory. Thus, initial or default settings for a power management contracts 218 may be associated with different accessories and appropriate contracts may be activated upon initial connection and authorization of the different accessories. The initially activated power management contracts 218 may be modified thereafter based upon conditions including but not limited to relative states of charge (RSOC) for batteries of the system components, power loads being serviced, a number of peripherals 212 connected to the host and/or accessory, power source availability for system components, power supply characteristics, processing loads, and so forth. Thus, rather than fixing operating constraints for power exchange at the time accessories and/or peripherals are connected to the system, the power management contracts discussed herein are designed to enable dynamic adjustments to such constraints in response to changing conditions at any time during connection of an accessory to a host. Such modifications of initial settings for a power management contract 218 based on “real-time” conditions may be initiated by accessory devices and/or by the host computing device.

The security module 216 represents functionality operable to identify and/or authenticate accessory devices when the devices are attached/connected to the computing devices. The security module 216 may be configured to implement a variety of different authentication techniques. Generally speaking, the security module 216 performs an authentication sequence in which credentials 220 (e.g., device ID/password, alphanumeric code, an identifying resistor value, etc.) associated with an accessory device 104 are obtained and verified. In one approach, the security module 216 is configured to provide functionality to support techniques for reversible connections of the connector 211 to the accessory port. For example, the security module 216 may represent functionality of the one or more microcontrollers 202 to detect insertion of the connector into the accessory port, sample detection pins of the connector 211 to ascertain an orientation of the connector as being straight or reversed according to values for the detection pins, and/or distinguish between different types of devices and/or communication protocols based on the sampling. Distinguishing between different types of devices may include distinguishing between two wire devices that utilize separate RX and TX lines and one wire devices for which RX/TX is combined on a single line or channel. Additionally, the security module 216 may represent functionality to set-up signal routing accordingly based on the ascertained orientation and/or the type of device.

Further, the accessory device 104 in FIG. 2 is illustrated as including example credentials 220, which may be provided to the security module 216 for authentication upon request. If the credentials are valid (e.g., the device is a recognized device that has associated privileges), the authentication is considered successful and the accessory device 104 may be authorized for power exchange through the power controller 112 and other interaction with the host computing device 102. Moreover, the credentials 220 may be associated with power management contract settings maintained for authorized device and therefore may be used to look-up and activate such settings (e.g., initial or default settings) for different devices upon successful authentication. On the other hand, if the credentials are not valid, interaction of the accessory device 104 with the computing device 102 may be restricted in various ways and/or prevented. Thus, the security module 216 may prevent unauthorized and/or unsupported devices from supplying/using power in ways that may be inefficient and/or unsafe.

Having considered the preceding discussion of an example operating environment, system, and devices, consider now a discussion of example devices, procedures, and scenarios which includes further details regarding techniques to implement reversible connectors for accessory devices.

Reversible Connector Details

FIG. 3 depicts generally a 300 an example scenario for reversible connection of a connector to an accessory port in accordance with one or more implementations. In this example, representative views of a connector 211 in both straight and reverse orientations is depicted. As mentioned, techniques for reversible connectors discussed herein may rely upon dedicated detection pins of the connector 211 and corresponding circuits/signals formed via the detection pins. In one approach, a pair of detection pins are employed for an interface 106 to support hot plug detection and communications for device authentication, power exchange, signal routing control, and so forth. The interface 106 is configurable based on the type of device and/or connector orientation to switch between different signal routing options (e.g., straight/reverse) and communication techniques (one wire/two wire).

Here, a detection pin pair including a pin A 302 (also referred to herein as “HPD1A”) and a pin B 304 (also referred to herein as “HPD1B”) is depicted. Although one pair of detection pins is shown, generally speaking two or more detection pins may be allocated for hot plug detection of accessories and be sampled to facilitate resolution of connector orientation and device type based on the signals conveyed/read via the detection pins. In the illustrated example, pin A 302 and pin B 304 are shown as being located generally on opposite edges and/or sides of a head of the connector 211. A variety of other pins 306 to support different communication protocols, buses, and high speed signals are also incorporated in the connector 211. By way of example, in addition to providing pins for authentication/power exchange/control, the connector 211 may provide pins to support USB, audio/video signals, a display port, network communications, and so forth. Generally, the pins are arranged as high speed pairs of pins. The pins 302, 304, 306 are configured to mate with a set of complimentary pins 308 included with an accessory port 210 of the host computing device.

In the illustrated arrangement pin A 302 and pin B 304 are configured to mate respectively with RX and TX pins associated with the accessory port 210 of the host computing device 102 in the “straight” orientation. In this arrangement, RX signals may be conveyed via pin A 302 and TX signals may be conveyed via pin B 304. When the connector is flipped or reversed to assume the “reverse” orientation also depicted in FIG. 3, pin B 304 now mates with the RX pin and pin A 302 now mates with the TX pin. In other words, these pin connections have physically changed positions. In the absence of correcting for the reversal, the RX/TX may end up crossed.

The host computing device, though, may include or otherwise make use of a switching mechanism 310 to “straighten-out” the signal routing. The switching mechanism provides functionality operable to control routing of signals such that the signals are communicated effectively between the same endpoints regardless of the connector orientation. The switching mechanism 310 is used to selectively change the signal pathways for the system to configure the accessory port and/or corresponding interface based on the connector orientation and/or for the particular type of device. Thus, for example, even when the connector is in the “reverse” orientation depicted in FIG. 3, the switching mechanism 310 may operate to change signal routing so that RX signals are still conveyed via pin A 302 and TX signals are conveyed via pin B 304. By way of example, the switching mechanism 310 may include one or more multiplexers 312 and/or switches 314 to enable control over the signal pathways. Although, the switching mechanism 310, multiplexers 312, and switches 314 are shown as components of the host device, multiplexers 312 and switches 314 employed to selectively reverse some signal pathways may be associated with an accessory device 104 in addition or alternatively to the switching mechanism 310, multiplexers 312, and switches 314 of the host. In this case, the host computing device 102 may operate to send commands to the accessory to cause set-up of signal routing via accessory signal switching components under the direction of the host.

FIG. 4 depicts generally at 400 a representative example showing details of but one example arrangement of pins for a connector head 402 of a connector 211. In this example, the connector includes forty pins. Pin A 302 and pin B 304 are shown as being on opposite ends of the connector head 402 and on opposite sides of the connector 211. Pin A 302 and Pin B 304 are labeled in the example as “HPD1A” and “HPD1B,” respectively. The labels “HPD1A” and “HPD1B” are used interchangeably with the terms Pin A and Pin B in this document. Various other pins 306 for conveyance of different types of signals and data are also disposed within the connector head 402, including for example pins for USB3, USB2, power exchange, and so forth. The example pin arrangements shown and described in FIGS. 3 and 4 are meant as illustrative examples only and are not intended to limit the arrangements of pins and connector configurations that may be employed in accordance with the described techniques. Additional details regarding techniques associated with reversible connectors for accessory devices are discussed in relation to the following example procedures.

Example Procedures

The following discussion describes techniques that may be implemented utilizing the previously described systems and devices. Aspects of each of the procedures may be implemented in hardware, firmware, software, or a combination thereof. The procedures are shown as a set of blocks that specify operations performed by one or more devices and are not necessarily limited to the orders shown for performing the operations by the respective blocks. In portions of the following discussion, reference may be made to the example operating environment 100 of FIG. 1 and the example devices and scenarios of FIGS. 2-4. Aspects of the procedures may be performed by a suitably configured computing device, such as the example host computing device 102 of FIG. 2 that includes or otherwise make use of one or more microcontrollers 202 to support reversible connectors 211. In addition or alternatively, aspects of the procedures may be performed via an accessory device, such as the example accessory device 104 of FIG. 2 that includes or otherwise make use of one or more microcontrollers 206.

FIG. 5 depicts an example procedure 500 in which signal routing is set-up in accordance with orientation of reversible connector. Connection is detected of a connector for an accessory device to an accessory port of a host computing device, the connector and accessory port configured to support reversible connection of the connector to the accessory port (block 502). For example, one or more microcontrollers 202 associated with a host computing device 102 may be configured to recognize connection of various devices to an accessory port 210. The detection may occur in various ways. In one approach, the one or more microcontrollers 202 are able to detect signals sent by an accessory device when a connector 211 is successfully attached to the accessory interface 210. The signals may comprise logic states, a voltage input signal, a pulsed pattern, static resistor values, and so forth. Alternatively the host computing device 102 may be configured to poll the accessory port 210 to determine when devices are attached or detached thereto, such as by monitoring detection lines and reading resistor values corresponding to the accessory. Attachment may initiate further processing to determine identity and/or device type associated with an accessory as well as orientation of the connector. Then, signal routing lines and/or the communication interface(s) between the host and accessory may be configured to match the type of accessory and orientation of the connector.

In particular, after attachment of the accessory device, an orientation of the connection of the connector to the accessory port is ascertained (block 504). The orientation may be resolved in various ways. Generally the orientation is determined based upon signals sampled on detection pins described herein. The particular values and/or patterns that are conveyed upon connection of a connector are indicative of the type of device as well as the connector orientation. Then, a switching mechanism of the host computing device is configured to automatically route signals according to the orientation (block 506). For example, one or more microcontrollers 202 of a host computing device may operate to configure a switching mechanism 310 in the manner previously described to set signal pathways based on an ascertained orientation of a connector 211. This may involve positioning of multiplexers 312 and switches 314 associated with the switching mechanism 310. In addition or alternatively, microcontrollers 202 may communicate with microcontrollers 206 of an accessory device 104 to notify the accessory device regarding the connector orientation and/or direct the accessory device 104 to reconfigure a switching mechanism on the accessory side accordingly to set-up appropriate signal routing. In this manner, endpoints for signal pathways may remain the same regardless of connector orientation. Thus, consumers may plug in accessories to a host device via a reversible cable in either orientation (straight or reverse) and the system automatically figures out the orientation and ensures that the signals do not get mixed up.

In one or more implementations, dedicated detection pins may be employed for hot plug detection and resolution of orientation as described herein. The detection may be based upon a voltage (e.g., 5V) that is applied to the detection lines and corresponding logic states for the pins, e.g., high=1, or low=0, that are obtained/read in response to the applied voltage. Different possible combinations of logic states for the detection lines may be associated with a set of detection cases each of which corresponds to a type of device and/or an orientation of a connector 211. Lines associated with the detection pins may be sampled together (e.g., in parallel or in sequence) and values for obtained for the different lines may be combined together to derive a combined logic state that is indicative of the device type and/or connector orientation. Accordingly, a table, file, database or other data structure may be established that reflects mapping of logic state combinations (or other credentials/accessory identifiers) with corresponding detection cases. In operation, the one or more microcontrollers 202 may monitor the detection pins and obtain values on each detection line. The microcontrollers 202 may make use of a mapping of the possible logic state combinations with corresponding detection cases to resolve the device type and connector orientation.

Regarding device type, the logic state combinations provide a mechanism to enable the host to distinguish between different types of devices. In particular, a detected logic state combination indicates whether a device is a one wire device that may communicate via a single line with RX and TX combined or a two wire device that uses two different lines for RX and TX. One wire devices may be relatively simple and low cost devices that do not use complex communication schemes, such as a basic power adapter or external battery. Two wire devices may be devices that provide functionality involving advanced interfaces, high speed communications, and/or multiple types of data/protocols, such as a docking station, multi-media accessory, and so forth.

In the case of a pair of detection pins allocated for hot plug detection, such as HPD1A and HPD1B (e.g., Pin A 302 and Pin B 304), there are four possible logic state combinations, e.g., high-high, high-low, low-high, and low-low. The logic states are indicative of the type of device (e.g., one wire or two wire) and may also be used to directly or indirectly resolve the connector orientation. In particular, both of the pins HPD1A and HPD1B are not asserted (e.g., in a low state) in the absence of a connected accessory. When an accessory device is connected to the host, the particular combination of the states for HPD1A and HPD1B determines the accessory type. For one wire devices, the line on which a high state is asserted can be determined. Accordingly, the logic state combination for a one-wire device also reflects the connector orientation and may be used directly to ascertain the orientation. For two wire devices, both lines have high states and thus the logic state combination may be insufficient to resolve the orientation. Therefore, additional processing may be performed as described below to ascertain the orientation of a two wire device.

Thus, for the detection pins HPD1A and HPD1B, the following shows an illustrative table showing an example mapping of possible logic state combinations to detection cases:

TABLE 1
Detection Pin Logic State Mapping
	HPD1A	HPD1A
	High = 1	Low = 0
	HPD1B	Two wire accessory	One wire accessory
	High = 1		(reverse)
	HPD1B	One wire accessory	No accessory attached
	Low = 0	(straight)

Per the above table, the values 1, 1 (high-high) indicates a two wire accessory, 1, 0 (high-low) indicates a one wire accessory in a straight orientation, 0, 1 (low-high) indicates a one wire accessory in a reverse orientation, and 0, 0 (low-low) indicates that no accessory is attached. After determining the device type using a mapping such as the example of Table 1, additional processing may occur to perform authentication/authorization of device, determine a particular identity and/or capabilities of the device (as opposed to just the one wire vs two wire determination), and set-up switching mechanisms of the host and/or accessory to route signals appropriately.

For example, for a one wire device, sampling may occur via the asserted pin (either HPD1A or HPD1B) to identify and authorize the device. This may involve various different authentication techniques as described previously. The authentication enables the host/microcontroller to recognize unsupported accessories and determine specific configuration information for supported accessories based on the particular accessory identity to configure the interface and signal routing accordingly. For instance, accessory devices may be configured to supply credentials 220 to the host in various ways as mentioned previously. In one approach, accessory devices are configured to expose a respective resistor value indicative of the identity for reading by the host computing device. Different resistor values may be associated with different accessories. Thus, when an accessory is connected, the host computing device may read a corresponding resistor value and distinguish between different accessories on this basis. Alternatively, other credentials 220 may be communicated to the host by an accessory to indicate its identity, such as sending a particular numeric code, an ID field value, a device name, and so forth.

As noted, when the attached accessory is a two wire device, the logic state combination is not sufficient to enable an orientation determination. In this case, orientation is resolved through the authentication sequence. In order to do so, supported two wire devices may be configured to supply credentials 220 to the host via either or both of the signal lines. In this case, sampling occurs for both of HPD1A or HPD1B to identify and authorize the two wire device. In one approach, the two wire device may have ID resistors associated with one or both lines and may expose the resistor value(s) indicative of the identity. Again, other credentials 220 may also be communicated to the host by an accessory to indicate its identity. Orientation may then be determined based on mapping of ID validity states for each line, e.g., valid or invalid, to possible orientation cases. Thus, for the detection pins HPD1A and HPD1B, the following shows an illustrative table showing an example mapping of ID validity states orientation cases:

TABLE 2
Two-Wire Detection Pin ID Validity State Mapping
	HPD1A:	HPD1A:
	valid ID	invalid ID
HPD1B:	Both orientations	2-wire accessory (reverse)
valid ID	supported. Configure based
	on application
HPD1B:	2-wire accessory (straight)	unsupported accessory
invalid ID

FIG. 6 depicts an example procedure 600 that illustrates example logic for processing that may occur to detect both device type and orientation in accordance with one or more implementations. In particular, the procedure 600 represents but one example technique that may be employed to resolve device type and connector orientation upon connection of an accessory to a host. The procedure 600 additionally represents one possible implementation of the mappings for detection pins HPD1A and HPD1B reflected in Table 1 and Table 2 described just above.

An accessory port is monitored (block 602) to detect connection of an accessory via a corresponding connector cord. The monitoring may be implemented by a microcontroller 202 and/or security module 216 as described herein. The accessory port 210 and connector 211 may be configured to have a pair of pins allocated for detection, e.g., detection pins HPD1A and HPD1B. A determination is made regarding whether either of pins HPD1A and HPD1B is asserted (e.g., signal value of high=1) (block 604). If not, monitoring of the port continues per block 602. If at least one of the pins is asserted, a check is made to determine if both pins are asserted (block 606). If both pins are not asserted, procedure 600 proceeds to operations associated with one wire configuration and otherwise both pins are asserted and procedure 600 proceeds to operations associated with two wire configuration.

For one wire configuration, determination is made regarding whether HPD1A is asserted (block 608) and if so, HPD1A is sampled (block 610) to obtain credentials for identification. Based on the credentials, an ID of the connected accessory is validated (block 612) and when the ID is valid, the system is configured for one wire in straight orientation (block 614). On the other hand, if the ID is not valid the accessory is an unsupported accessory (block 616) and interaction may be restricted. If HPD1A is not asserted per block 608, the other pin HPD1B is the asserted pin and is sampled (block 618). ID validation again occurs (block 620) and either, the ID is valid and the system is configured for one wire in reverse orientation (block 622) or the ID is not valid the accessory is an unsupported accessory (block 616) and may be restricted.

For two wire configuration, both HPD1A and HPD1B are sampled (block 624). ID validation occurs for HPD1A (block 626) and then for HPD1B (block 628) if the ID sampled on HPD1A is valid. If IDs for both HPD1A and HPD1B are valid, then both straight and reverse orientations are supported and configuration occurs based on the application (block 630). Otherwise, if just the ID for HPD1A is valid, then the system is configured for two wire in straight orientation (block 632). If HPD1A is not valid per block 626, ID validation occurs for HPD1B (block 634). If HPD1B is valid per block 634, then system is configured for two wire in reverse orientation (block 636). Otherwise, IDs sampled for both HPD1A and HPD1B are invalid and the accessory is an unsupported accessory (block 638) and may be restricted. Following configuration of the system in the appropriate way based on the depicted logic, signals are the routed using the configuration that us applied (block 640).

Example procedure 600 may be implemented in software, firmware, hardware, or a combination of each or some of same. A software or firmware implementation may be advantageously flexible and reconfigured with a software or firmware update. Alternatively, example procedure 600 may be implemented using discrete logic gates and analog and mixed-signal circuits, including analog-to-digital circuits. This alternative may be advantageously faster and may also comprise programmable thresholds, for example, for determining resistor values. Because of the binary nature of the decisions, digital logic may be used extensively.

Having considered the foregoing example procedures, consider now a discussion of example systems and devices that may be employed to implement aspects of reversible connector techniques in one or more embodiments.

Example System and Device

FIG. 7 illustrates an example system generally at 700 that includes an example computing device 702 that is representative of one or more computing systems and/or devices that may implement the various techniques described herein. The computing device 702 may be, for example, be configured to assume a mobile configuration through use of a housing formed and size to be grasped and carried by one or more hands of a user, illustrated examples of which include a mobile phone, mobile game and music device, and tablet computer although other examples are also contemplated.

The example computing device 702 as illustrated includes a processing system 704, one or more computer-readable media 706, and one or more I/O interface 708 that are communicatively coupled, one to another. Although not shown, the computing device 702 may further include a system bus or other data and command transfer system that couples the various components, one to another. A system bus can include any one or combination of different bus structures, such as a memory bus or memory controller, a peripheral bus, a universal serial bus, and/or a processor or local bus that utilizes any of a variety of bus architectures. A variety of other examples are also contemplated, such as control and data lines.

The processing system 704 is representative of functionality to perform one or more operations using hardware. Accordingly, the processing system 704 is illustrated as including hardware element 710 that may be configured as processors, functional blocks, and so forth. This may include implementation in hardware as an application specific integrated circuit or other logic device formed using one or more semiconductors. The hardware elements 710 are not limited by the materials from which they are formed or the processing mechanisms employed therein. For example, processors may be comprised of semiconductor(s) and/or transistors (e.g., electronic integrated circuits (ICs)). In such a context, processor-executable instructions may be electronically-executable instructions.

The computer-readable storage media 706 is illustrated as including memory/storage 712. The memory/storage 712 represents memory/storage capacity associated with one or more computer-readable media. The memory/storage component 712 may include volatile media (such as random access memory (RAM)) and/or nonvolatile media (such as read only memory (ROM), Flash memory, optical disks, magnetic disks, and so forth). The memory/storage component 712 may include fixed media (e.g., RAM, ROM, a fixed hard drive, and so on) as well as removable media (e.g., Flash memory, a removable hard drive, an optical disc, and so forth). The computer-readable media 706 may be configured in a variety of other ways as further described below.

Input/output interface(s) 708 are representative of functionality to allow a user to enter commands and information to computing device 702, and also allow information to be presented to the user and/or other components or devices using various input/output devices. Examples of input devices include a keyboard, a cursor control device (e.g., a mouse), a microphone, a scanner, touch functionality (e.g., capacitive or other sensors that are configured to detect physical touch), a camera (e.g., which may employ visible or non-visible wavelengths such as infrared frequencies to recognize movement as gestures that do not involve touch), and so forth. Examples of output devices include a display device (e.g., a monitor or projector), speakers, a printer, a network card, tactile-response device, and so forth. Thus, the computing device 702 may be configured in a variety of ways to support user interaction.

The computing device 702 is further illustrated as being communicatively and physically coupled to an accessory device 714 that is physically and communicatively removable from the computing device 702. In this way, a variety of different input devices may be coupled to the computing device 702 having a wide variety of configurations to support a wide variety of functionality. In this example, the accessory device 714 includes one or more controls 716, which may be configured as press-sensitive keys, mechanically switched keys, buttons, and so forth.

The accessory device 714 is further illustrated as include one or more modules 718 that may be configured to support a variety of functionality. The one or more modules 718, for instance, may be configured to process analog and/or digital signals received from the controls 716 to determine whether an input was intended, determine whether an input is indicative of resting pressure, support authentication of the accessory device 714 for operation with the computing device 702, and so on.

Various techniques may be described herein in the general context of software, hardware elements, or program modules. Generally, such modules include routines, programs, objects, elements, components, data structures, and so forth that perform particular tasks or implement particular abstract data types. The terms “module,” “functionality,” and “component” as used herein generally represent software, firmware, hardware, or a combination thereof. The features of the techniques described herein are platform-independent, meaning that the techniques may be implemented on a variety of commercial computing platforms having a variety of processors.

An implementation of the described modules and techniques may be stored on or transmitted across some form of computer-readable media. The computer-readable media may include a variety of media that may be accessed by the computing device 702. By way of example, and not limitation, computer-readable media may include “computer-readable storage media” and “computer-readable signal media.”

“Computer-readable storage media” refers to media and/or devices that enable storage of information in contrast to mere signal transmission, carrier waves, or signals per se. Thus, computer-readable storage media does not include signals per se or signal-bearing media. The computer-readable storage media includes hardware such as volatile and non-volatile, removable and non-removable media and/or storage devices implemented in a method or technology suitable for storage of information such as computer readable instructions, data structures, program modules, logic elements/circuits, or other data. Examples of computer-readable storage media may include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, hard disks, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or other storage device, tangible media, or article of manufacture suitable to store the desired information and which may be accessed by a computer.

“Computer-readable signal media” may refer to a signal-bearing medium that is configured to transmit instructions to the hardware of the computing device 702, such as via a network. Signal media typically may embody computer readable instructions, data structures, program modules, or other data in a modulated data signal, such as carrier waves, data signals, or other transport mechanism. Signal media also include any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media include wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media.

As previously described, hardware elements 710 and computer-readable media 706 are representative of modules, programmable device logic and/or fixed device logic implemented in a hardware form that may be employed in some embodiments to implement at least some aspects of the techniques described herein, such as to perform one or more instructions. Hardware may include components of an integrated circuit or on-chip system, microcontroller devices, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a complex programmable logic device (CPLD), and other implementations in silicon or other hardware. In this context, hardware may operate as a processing device that performs program tasks defined by instructions and/or logic embodied by the hardware as well as a hardware utilized to store instructions for execution, e.g., the computer-readable storage media described previously.

Combinations of the foregoing may also be employed to implement various techniques described herein. Accordingly, software, hardware, or executable modules may be implemented as one or more instructions and/or logic embodied on some form of computer-readable storage media and/or by one or more hardware elements 710. The computing device 702 may be configured to implement particular instructions and/or functions corresponding to the software and/or hardware modules. Accordingly, implementation of a module that is executable by the computing device 702 as software may be achieved at least partially in hardware, e.g., through use of computer-readable storage media and/or hardware elements 710 of the processing system 704. The instructions and/or functions may be executable/operable by one or more articles of manufacture (for example, one or more computing devices 702 and/or processing systems 704) to implement techniques, modules, and examples described herein.

CONCLUSION

Although the example implementations have been described in language specific to structural features and/or methodological acts, it is to be understood that the implementations defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as example forms of implementing the claimed features.

Claims

1. A method implemented by a host computing device comprising: detecting connection of a connector to an accessory port of the host computing device based on signals conveyed via a pair of detection pins allocated in the connector;ascertaining an orientation of the connection of the connector to the accessory port based on the signals, the signals indicating a logic state combination for the pair of detection pins, the logic state combination indicating whether an accessory device connected via the connector is a one wire device or a two wire device; andconfiguring a switching mechanism of the host computing device to route signals according to the ascertained orientation and the logic state combination.

2. A method as described in claim 1, wherein detecting connection of the connector comprises sampling the signals conveyed via the pair of detection pins together and combining values that are obtained via the pair of detection pins to derive the logic state combination.

3. A method as described in claim 2, wherein sampling the signals conveyed via the pair of detection pins together comprises sampling the signals in parallel.

4. A method as described in claim 1, wherein the pair of detection pins form an interface to support hot plug detection and communications for device authentication, power exchange, and signal routing control.

5. A method as described in claim 4, wherein the interface is configurable based on a device type of the accessory device connected and the orientation of the connection to switch between different signal routing options and communication techniques.

6. A method as described in claim 1, wherein configuring the switching mechanism comprises directing positions for switches and multiplexers of the host computing device to produce straight or reversed signal paths according to the ascertained orientation.

7. A method as described in claim 6, wherein configuring the switching mechanism further comprises sending commands to the accessory device to cause set-up of signal routing via signal switching components of the accessory device under the direction of the host computing device.

8. A method as described in claim 1, wherein ascertaining an orientation of the connection of the connector comprises: sampling signals associated with allocated detection pins of the connector to determine a device type for the accessory device as a one wire device or a two wire device; andwhen the device type is a one wire device, determining the orientation of the connection directly from the sampled signals; orwhen the device type is a two wire device, resolving the orientation through an authentication sequence in which credentials supplied by the accessory device are employed to establish validity states for the detection pins indicative of the orientation.

9. A method as described in claim 8, wherein the credentials supplied by the accessory device comprise one or more resistor values exposed on one or more detection lines formed via the detection pins.

10. A host computing device comprising: one or more microcontrollers;an accessory port connectable to a connector for an accessory device;one or more computer-readable storage media storing instructions that when executed via the one or more microcontrollers cause the host computing device to perform operations including:detecting insertion of the connector into the accessory port via a pair of detection pins integrated with the connector;obtaining a logic state combination of high and low logic states conveyed via the pair of detection pins;determining a device type for the accessory device as a one wire device or a two wire device based upon the logic state combination;ascertaining an orientation of the connector inserted in the accessory port including: when the device type is a one wire device, determining the orientation of the connection directly from the logic state combination; orwhen the device type is a two wire device, sampling resistor values for one or more identity resistors of the accessory device via the pair of detection pins to establish validity states indicative of the orientation; andsetting-up signal routing according to the type of device and ascertained orientation.

11. A host computing device as described in claim 10, wherein a one wire device is a device that communicates via RX/TX that is combined on a single line and a two wire device is a device that communicates using separate RX and TX lines.

12. A host computing device as described in claim 10, wherein setting-up signal routing according to the type of device and ascertained orientation includes configuring a switching mechanism to route signals in straight or reversed signal paths according to the ascertained orientation.

13. A host computing device as described in claim 10, wherein determining the device type based upon the logic state combination comprises referencing a mapping of possible logic state combinations to detection cases to identify the device type.

14. A host computing device as described in claim 10, wherein the instructions further cause the host computing device to sample credentials supplied by the accessory device to determine whether the accessory device is an authorized device authorized for interaction with the host computing device or an unsupported device with which interaction is restricted.

15. A host computing device as described in claim 10, wherein the instructions are implemented via firmware corresponding to the one or more microcontrollers of the host computing device and the one or more microcontrollers are configured to operate independently of a primary processing system of the host computing device.

16. A host computing device comprising: a processing system; andone or more computer-readable storage media storing instructions that when executed via the processing system cause the host computing device to implement a security module that is configured to: detect connection of a connector for an accessory device to an accessory port of the host computing device based on a logic state combination obtained via a pair of detection pins integrated with the connector, the connector and accessory port configured to support reversible connection of the connector to the accessory port;identify a device type of the accessory device according to the logic state combination, the logic state combination indicating whether the accessory device is a one wire device or a two wire device;ascertain an orientation of the connection of the connector to the accessory port; andconfigure a switching mechanism of the host computing device to automatically route signals according to the identified device type and the ascertained orientation.

17. A host computing system as recited in claim 16, wherein the pair of detection pins form an interface to support hot plug detection and communications for device authentication, power exchange, and signal routing control.

18. A host computing system as recited in claim 16, wherein the switching mechanism is configured based on: positions being set for switches and multiplexers of the host computing device to produce straight or reversed signal paths according to the ascertained orientation; andcommands being sent to the accessory device to cause set-up of signal routing on the accessory side via signal switching components of the accessory device under the direction of the host computing device.

19. A host computing system as recited in claim 16, wherein the logic state combination includes high and low logic states conveyed via the pair of detection pins.

20. A host computing system as recited in claim 16, wherein the orientation of the connection of the connector to the accessory port is ascertained based on: a determination of the orientation directly from the logic state combination when the device type is a one wire device; oran authentication sequence in which credentials supplied by the accessory device are employed to establish validity states for the detection pins indicative of the orientation when the device type is a two wire device.