Encoding data in multiple formats
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.
1. A computer implemented method of communication between a card reader and a user device, comprising:
receiving, from a read head of the card reader coupled to the user device, card information on a payment card;
encoding the card information in a fast format packet to be sent to the user device at a first data rate;
encoding the card information in a slow format packet to be sent to the user device at a second data rate lower than the first data rate;
modulating the fast format packet and the slow format packet together into a signal that includes at least a first portion that corresponds to the fast format packet and at least a second portion that corresponds to the slow format packet and sending the signal over a communication port of the user device;
initiating, at the user device, a demodulation process on the first portion of the signal that corresponds to the fast format packet;
determining that the demodulation process on the portion of the signal that corresponds to the fast format packet has failed;
in response to determining that the demodulation process on the portion of the signal that corresponds to the fast format packet has failed, demodulating the portion of the signal that corresponds to the slow format packet; and
decoding the card information from the demodulated slow format packet.
2. The method of claim 1 , further comprising:
receiving the portion of the signal that corresponds to the slow format packet before or while performing the demodulation process on the portion of the signal corresponding to the fast format packet.
3. The method of claim 1 , wherein sending, to the user device, the card information encoded in the first format and the second format comprises sending a portion of the signal corresponding to the fast format before a portion of the signal corresponding to the slow format.
4. A computer implemented method of communication between a card reader and a user device, comprising:
receiving, from a read head of the card reader, card information associated with a card;
encoding the card information in a first format to be sent to the user device at a first data rate;
encoding the card information in a second format to be sent to the user device at a second data rate lower than the first data rate;
sending, to the user device, the card information encoded in the first format and the second format together as a signal that includes at least a first portion that corresponds to the first format and at least a second portion that corresponds to the second format; and
in response to determining that a demodulation process on the first portion of the signal that corresponds to the first format has failed, demodulating the second portion of the signal that corresponds to the second format.
5. The method of claim 4 , wherein sending, to the user device, the card information encoded in the first format and the second format comprises sending the signal over an audio channel of the user device.
6. The method of claim 4 , wherein sending, to the user device, the card information encoded in the first format and the second format comprises sending the signal over a data communications port of the user device.
7. The method of claim 4 , wherein sending, to the user device, the card information encoded in the first format and the second format comprises sending the portion of the signal that corresponds to the slow format before or while the user device is performing a demodulation process on the portion of the signal corresponding to the fast format.
8. The method of claim 4 , wherein sending, to the user device, the card information encoded in the fast format and the second format comprises sending the portion of the signal corresponding to the fast format before sending the portion of the signal corresponding to the slow format.
9. A computer implemented method of communication between a card reader and a user device, comprising:
receiving, from the card reader a signal that includes encoded card information associated with a card, wherein the card information is encoded in a first format received at a first data rate and a second format received at a second data rate that is lower than the first data rate, and the signal includes at least a first portion that corresponds to the first format and at least a second portion that corresponds to the second format;
initiating a demodulation process on the portion of the signal that corresponds to the first format;
determining that the demodulation process on the portion of the signal that corresponds to the first format has failed;
in response to determining that the demodulation process on the portion of the signal that corresponds to the first format has failed, demodulating the portion of the signal that corresponds to the second format.
10. The method of claim 9 , further comprising:
receiving the portion of the signal that corresponds to the second format before or while performing the demodulation process on a portion of the signal corresponding to the first format.
11. The method of claim 9 , wherein receiving, form the card reader, the signal card information associated with the card comprises receiving a portion of the signal corresponding to the first format before a portion of the signal corresponding to the second format.
12. The method of claim 9 , wherein receiving, from the card reader, the signal card information associated with a card comprises receiving the signal over an audio channel of the user device.
13. The method of claim 9 wherein receiving, from the card reader, the signal card information associated with the card comprises receiving the signal over a data communications port of the user device.
14. A card reader configured to encode card information associated with a card obtained from a read head into a fast format to be sent to a user device at a first data rate, encode the card information in a slow format to be sent to the user device at a second data rate lower than the first data rate, send, to the user device, the card information encoded in the first format and the second format as a signal that includes at least a first portion that corresponds to the fast format and at least a second portion that corresponds to the slow format, and, in response to determining that the demodulation process on the portion of the signal that corresponds to the fast format has failed, demodulate the portion of the signal that corresponds to the slow format.
15. The card reader of claim 14 , wherein the card reader is further configured to send, to the user device, the portion of the signal corresponding to the fast format before the portion of the signal corresponding to the slow format.
16. The card reader of claim 14 , wherein the card reader is further configured to send a portion of the signal that corresponds to the slow format before or while the user device is performing a demodulation process on a portion of the signal corresponding to the fast format.