Methods of transmitting information to mobile devices using cost effective card readers
A method of transmitting information to a mobile device includes providing a card reader is provided with a read head, a slot for swiping a magnetic stripe of a card and device electronics that includes an analog front-end and a microcontroller. The analog to digital front end is coupled to a processing element in the microcontroller. A raw magnetic head signal is received at the analog to digital front end. The raw magnetic head signal is converted into a processed digital signal that the microcontroller can interpret. An output jack output jack signal is delivered to the mobile device.
1. A device for receiving payment card information comprising:
a read head configured to convert encoded payment information stored on a payment card into a raw magnetic head signal;
an amplifier configured to amplify the raw magnetic head signal;
a differentiator configured to detect peaks in the amplified raw magnetic head signal and produce a differentiated signal;
a comparator configured to receive the differentiated signal and output a processed digital signal encoding the payment card information;
a processor configured to receive the processed digital signal encoding the payment card information;
a passive id circuit including a charge pump configured to receive a bias voltage from an electrical connector, and a memory device; and
a battery configured to provide a power source to the amplifier, differentiator, comparator and the processor.
2. The device of claim 1 wherein, the processor is further configured to control power flow to the amplifier, the differentiator, and the comparator.
3. The device of claim 1 further comprising a male audio connector, the male audio connector is operatively connected to an output of the processor.
4. The device of claim 1 , wherein the charge pump is configured to step up the bias voltage to at least an operating voltage of the memory device, and the passive id circuitry is configured to transmit a unique id of the device for receiving payment card information over the electrical connector.
5. The device of claim 1 , further comprising:
an electrical connector configured to connect the device for receiving payment card information to an external device; and
a wake up circuit configured to receive a bias voltage from the electrical connector, and to detect an initiated payment card swipe, and provide a signal to the processor to wake up from a sleep state.
6. A device for receiving payment card information comprising:
a read head;
an amplifier operatively coupled to the read head and configured to amplify an output of the read head;
a differentiator operatively coupled to the amplifier and configured received the amplified output from the read head and to produce a differentiated signal;
a comparator operatively coupled to the differentiator and configured to receive the differentiated signal and output a processed digital signal;
a processor operatively coupled to the differentiator and configured to receive the processed digital signal;
a male audio connector, the male audio connector is operatively connected to an output of the processor
a passive id circuit including a charge pump and a memory device, the charge pump being operatively connected to a first line of the male audio connector, and the memory device being operatively coupled to a second line of the male audio connector; and
a battery operatively coupled to the amplifier, and the processor.
7. The device of claim 6 , further comprising:
a wake up circuit operatively connected to a first line of the male audio connector, and connected to the processor.