METHOD OF TRANSMITTING INFORMATION FROM A SMALL CARD READER TO A MOBILE DEVICE

1 . A method of transmitting information to a mobile device, comprising:

providing a card reader that includes a read head with a slot and an output jack,

sliding a card in the slot;

reading data from the magnetic stripe;

producing a raw magnetic signal indicative of data stored on the magnetic stripe;

converting the raw magnetic head signal into a processed digital signal that the microcontroller can interpret;

accommodating rocking of the card while being swept in the slot while producing a successful read of the magnetic stripe of the card, the rocking being in an amount of 1 to 10 degrees of rotation of a bottom surface of the card away from a bottom surface of the slot; and

sending an output jack signal to the mobile device.

2 . The method of claim 1 , wherein the rotation is in direction of a plane of the card.

3 . The method of claim 1 , wherein accommodation of rocking enables a bottom of the card to be moved in a direction away from a bottom of the slot while the card is slid through the slot.

4 . The method of claim 1 , wherein the read head includes an analog front-end, the analog to digital front end being coupled to a processing element in the microcontroller.

5 . The method claim 1 , further comprising:

producing an encrypted output jack signal.

6 . The method of claim 1 , further comprising:

producing an encrypted and signed output jack signal.

7 . The method of claim 1 , further comprising;

producing a synchronous Manchester encoded stream output jack signal.

8 . The method of claim 1 , further comprising:

producing an asynchronized stream output jack signal.

9 . The method of claim 1 , further comprising:

producing an output jack signal at a frequency that the output jack signal appears to look AC to a microphone input of the mobile device.

10 . The method of claim 1 , further comprising:

producing an output jack signal at a frequency of 2 KHz to 48 kHz.

11 . The method of claim 1 , further comprising:

capturing card readings at the digital front end that are swept at a rate of 5 inches to 50 inches per second.

12 . The method of claim 1 , further comprising:

sending the output jack signal to the mobile device at a constant baud rate.

13 . The method of claim 12 , wherein the constant baud rate is 2400 to 9200 baud.

14 . The method of claim 1 , wherein the front end includes, an amplifier/filter, differentiator, a comparator and wake-up electronics.

15 . The method of claim 14 , further comprising:

using the wake-up electronics to signal the microcontroller, which in turn puts the device electronics into an active mode from a sleep mode, and back into the sleep mode when a card swipe signal stops.

16 . The method of claim 15 , further comprising:

powering down the wake-up electronics by the microcontroller when the device electronics is in the active mode.

17 . The method of claim 15 , further comprising:

powered the wake-up electronics by a microphone bias of the mobile device.

18 . The method of claim 15 , further comprising;

detecting by the wake-up electronics detects when there is an edge from leading zeros of a card being swiped and alerting to wake up the microcontroller and device electronics.

19 . The method of claim 15 , further comprising:

waking up the device electronics in enough time to process and encrypt a card swipe signal.

20 . The method of claim 1 , wherein the device electronics includes an amplifier/filter, differentiator, comparator, transmission electronics, and the microcontroller.

21 . The method of claim 20 , further comprising:

amplifying a raw magnetic head signal by the amplifier/filter and processing before the microcontroller accepts it as an input.

22 . The method of claim 21 , further comprising:

taking the output of the amplifier/filter by the differentiator and differentiating it to look for peaks in the input signal.

23 . The method of claim 22 , further comprising:

using the comparator to take the output of the differentiator and compares it to a reference voltage and produces an output that is a processed digital version of a magnetic swipe.

24 . The method of claim 23 , further comprising:

using the comparator looks for where an input signal crosses zero.

25 . The method of claim 24 , further comprising:

using the microcontroller accepts the comparator input; and

processing the comparator input and encrypting at least a portion of data of the comparator input.

26 . The method of claim 24 , further comprising:

using the microcontroller to control power to the amplifier/filter, differentiator and comparator.

27 . The method of claim 24 , further comprising:

using the transmission electronics to accept output data of the microcontroller as an input and using this to modulate a microphone-bias line of the mobile device.

28 . The method of claim 27 , further comprising:

using the microphone-bias line for power and data transmission back to the mobile device.

29 . The method of claim 1 , further comprising:

using the microcontroller to convert raw bit patterns into formatted credit card information.

30 . The method of claim 1 , further comprising:

using the microcontroller to independently determine if swiped card data is valid.