Abstract: A card reader includes a body, the body being configured for coupling with a device, the device including a device light sensor and a device light source; a reader light sensor that is configured to capture light being emitted from the device light source, wherein, when the body is coupled to the user device, the reader light sensor is positioned adjacent to the device light source; a reader light source that is configured to emit light to the device light sensor, wherein, when the body is coupled to the user device, the reader light source is positioned adjacent to the device light sensor; a reader interface positioned in the body and configured to read the card; and circuitry configured to communicate data between the card reader and the user device using the reader light sensor and the reader light source.

Abstract: A card reader includes a body, the body being configured for coupling with a device, the device including a device light sensor and a device light source; a reader light sensor that is configured to capture light being emitted from the device light source, wherein, when the body is coupled to the user device, the reader light sensor is positioned adjacent to the device light source; a reader light source that is configured to emit light to the device light sensor, wherein, when the body is coupled to the user device, the reader light source is positioned adjacent to the device light sensor; a reader interface positioned in the body and configured to read the card; and circuitry configured to communicate data between the card reader and the user device using the reader light sensor and the reader light source.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for modulating card information between a card reader and a user device. One of the methods includes receiving, from a read head of the card reader, card information associated with a card. The card information is encoded in a first format to be sent to the user device at a first data rate. The card information is encoded in a second format to be sent to the user device at a second data rate lower than the first data rate. The card information is sent to the user device encoded in the first format and the second format.

Abstract: Approaches provide for a mobile point-of-sale system configured to facilitate the transfer of funds between entities (e.g., customers and merchants). A card reader can include two different types of slots configured for conducting a financial transaction between entities. A first slot can allow for a magnetic stripe element of a card to be swiped. A second slot can include contact elements which allow the card to be “dipped in”. In this way, the device can receive a swipe and/or a “dipping” of a card into a respective slot for conducting a financial transaction.

Abstract: A card reader includes a body, the body being configured for coupling with a device, the device including a device light sensor and a device light source; a reader light sensor that is configured to capture light being emitted from the device light source, wherein, when the body is coupled to the user device, the reader light sensor is positioned adjacent to the device light source; a reader light source that is configured to emit light to the device light sensor, wherein, when the body is coupled to the user device, the reader light source is positioned adjacent to the device light sensor; a reader interface positioned in the body and configured to read the card; and circuitry configured to communicate data between the card reader and the user device using the reader light sensor and the reader light source.

Abstract: The subject technology relates to methods for processing a payment using a mobile card reader. Implementations of the subject technology provide include steps for determining, using a first communication module, a first available bandwidth for data transacted between the card reader and a payment processing service, and determining, using the second communication module, a second available bandwidth for data transacted between a local device and the payment processing service. In some implementations, the method can further include steps for selecting a communication path for communicating with the payment processing service based on the first available bandwidth and the second available bandwidth. Systems and computer-readable media are also provided.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for modulating card information between a card reader and a user device. One of the methods includes receiving, from a read head of the card reader, card information associated with a card. The card information is encoded in a first format to be sent to the user device at a first data rate. The card information is encoded in a second format to be sent to the user device at a second data rate lower than the first data rate. The card information is sent to the user device encoded in the first format and the second format.

Abstract: Methods, systems, and apparatus, for pairing a wireless card reader and a computing device, including: receiving first user input setting the wireless card reader in a pairing mode; sending an indication from the wireless card reader to the computing device that a pairing mode of the wireless card reader is enabled; receiving an indication from the computing device that a pairing mode of the computing device is enabled; receiving, in the wireless card reader, a second user input of a sequence of actuations of a sensor on the wireless card reader; determining, on the wireless card reader, whether the sequence of actuations matches a stored sequence; and in response to determining that the sequence of actuations matches a stored sequence, pairing the wireless card reader with the computing device.

Abstract: Read head array stitching techniques are described. A card reader includes an array of magnetic sensors (a read head array) for retrieving account information from a magnetic stripe of a financial transaction card. The magnetic sensors can be arranged in rows and columns. During a card swipe, each magnetic sensor receives a series of readings. A processor determines relative bit rates for each series of readings. The processor determines which sensor corresponds to which track of the magnetic stripe based on a comparison of the relative bit rates. The processor generates a data stream for at least one track based on portions of readings from each sensor during periods of time the sensor is determined to correspond to the track.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for modulating card information between a card reader and a user device. One of the methods includes receiving, from a read head of the card reader, card information associated with a card. The card information is encoded in a first format to be sent to the user device at a first data rate. The card information is encoded in a second format to be sent to the user device at a second data rate lower than the first data rate. The card information is sent to the user device encoded in the first format and the second format.

Abstract: The subject technology relates to methods for processing a payment using a mobile card reader. Implementations of the subject technology provide include steps for determining, using a first communication module, a first available bandwidth for data transacted between the card reader and a payment processing service, and determining, using the second communication module, a second available bandwidth for data transacted between a local device and the payment processing service. In some implementations, the method can further include steps for selecting a communication path for communicating with the payment processing service based on the first available bandwidth and the second available bandwidth. Systems and computer-readable media are also provided.

Abstract: Methods, systems, and apparatus, for pairing a wireless card reader and a computing device, including: receiving first user input setting the wireless card reader in a pairing mode; sending an indication from the wireless card reader to the computing device that a pairing mode of the wireless card reader is enabled; receiving an indication from the computing device that a pairing mode of the computing device is enabled; receiving, in the wireless card reader, a second user input of a sequence of actuations of a sensor on the wireless card reader; determining, on the wireless card reader, whether the sequence of actuations matches a stored sequence; and in response to determining that the sequence of actuations matches a stored sequence, pairing the wireless card reader with the computing device.

Abstract: A card reader includes a body, the body being configured for coupling with a device, the device including a device light sensor and a device light source; a reader light sensor that is configured to capture light being emitted from the device light source, wherein, when the body is coupled to the user device, the reader light sensor is positioned adjacent to the device light source; a reader light source that is configured to emit light to the device light sensor, wherein, when the body is coupled to the user device, the reader light source is positioned adjacent to the device light sensor; a reader interface positioned in the body and configured to read the card; and circuitry configured to communicate data between the card reader and the user device using the reader light sensor and the reader light source.

Abstract: A technique for tamper protection in an electronic device is disclosed. A conductive mesh is affixed onto one or more interior surfaces of the outer housing of the device. The mesh includes one or more conductive traces coupled to one or more detectors within the device. The detector can detect an open-circuit or short-circuit condition resulting from an unauthorized attempt to open the housing, and output a signal to trigger an appropriate countermeasure. The electrical contacts along the trace that are monitored can be selected differently from one manufactured unit to the next, and can be selected based on a randomness function. The selection of contacts may be made during or after manufacturing of the device. The mesh can include multiple metal traces that run very close together, in parallel, across one or more interior surfaces of the housing, allowing detection of both open-circuit and short-circuit conditions.

Abstract: A card reader includes a body, the body being configured for coupling with a device, the device including a device light sensor and a device light source; a reader light sensor that is configured to capture light being emitted from the device light source, wherein, when the body is coupled to the user device, the reader light sensor is positioned adjacent to the device light source; a reader light source that is configured to emit light to the device light sensor, wherein, when the body is coupled to the user device, the reader light source is positioned adjacent to the device light sensor; a reader interface positioned in the body and configured to read the card; and circuitry configured to communicate data between the card reader and the user device using the reader light sensor and the reader light source.

Abstract: The subject technology relates to methods and systems for processing a payment using a mobile card reader. Implementations of the subject technology provide a method for receiving payment information, wherein the payment information specifies a payment amount, generating an authorization request to process the payment information, encrypting the authorization request using an encryption engine to generate a secure authorization request and transmitting the secure authorization request using the radio transceiver to a payment processor via a messaging service, wherein the messaging service comprises one or more of a SMS, a MMS or an email service. In certain aspects, methods of the subject technology can further include steps for receiving an authorization response from the payment processor via the messaging service. Systems and methods for mobile card reader activation are also provided.

Abstract: Aspects of the subject disclosure provide a card reader for receiving payment card information at a mobile point-of-sale terminal. In some implementations, a reader of the subject technology can include a memory, a conditioning module and a 3.5 mm audio plug including an audio bus that is configured for insertion into a headphone port of a host device, such as a smart phone or tablet computer. Implementations of the subject technology also include a microprocessor configured to perform operations for receiving a training sequence for use in determining communication parameters associated with a mobile device, and in response to the training sequence, transmitting an acknowledgement signal to the mobile device, via the audio bus, to indicate that a communicative coupling with the mobile device has been successfully established.