CARDS AND SENSORS
BY: PRATEEK AGRAWAL
1) Smart cards
contact less cards
2) Types of cards(charts)
3) Cards construction
6) Types of sensor
7) Example of sensors
Smart cards (or Integrated Circuits cards or ICC) are small pocket-sized
cards with electronic processing circuits embedded in them. Some memory cards
and some have embedded microprocessor circuits.
Smart cards are divide into two:
Contact smart cards :
They have gold coated pins on the chip that
provide contact with the electrical circuits of the card reader when the
card is inserted in it.
Eg telephone cards in public telephones.
Contact-less smart cards: They communicate with card readers using the
radio frequency induction technology. These cards have to be held close to
the reader’s antenna.
The chip embedded in a smart card is a circuit including a computer, memory
and transceiver. The chip lies in between the inner layers of the card.
Smartcards do not have batteries. The energy is provided by the card reader.
The computer in the card is activated by power
(through radiation in a
contact less card and through the IC pins on the card surface in a contact card)
from a nearby reader called host.
Application protocol data unit(APDU) is an accepted standard for card-host
SMART CARD CONSTUCTION
Mostly all chip cards are built from layers of
brought together properly gives the card a specific
life and functionality. The typical card today is
made from PVC, Polyester or Polycarbonate. The card
layers are printed first and then laminated in a
large press. The next step in construction is the
embedding a chip and then adding data to the card.
In all, there may be up to 30 steps in constructing
a card. The total components, including software
and plastics, may be as many as 12 separate items;
all this in a unified package that appears to the
user as a simple device.
Applications of smart cards:
For financial transactions as a credit or ATM / debit
Can store personal id or medical reports.
An employee can use it to open security locks at work
and log in.
A student uses it to get books issued from library.
environment; for eg: there are sensors for temperature, pressure,
The sensor sends the signals to a computer or controller.
A sensor maybe a CCD(charge coupled device) camera to identify
various objects or a microphone to recognize voices. Sensors in a
It consists of the sensing device, processor, memory, analog
to digital converter(ADC), signal processing element, wireless or
infrared receiver and transmitter, and performs communicational
and computational functions.
Sensors are programmed using assembly language or C.
Typically interested in electronic sensor
• convert desired parameter into electrically measurable signal
• General Electronic Sensor
• primary transducer: changes “real world” parameter into electrical signal
• secondary transducer: converts electrical signal into analog or digital values
• Typical Electronic Sensor
Examples of sensors:
Sensor for surrounding light can be used to control the brightness
of the LCD screen.
Sensor for measuring the strength of the signal received, controls
the amplification of received signals.
amplification during a call.
Examples of sensors used in robotic systems:
Acceleration and force sensors in the right and left feet
Infrared distance sensors at the head and hands
Microphones in ears etc.
There are two types of cards contact and contact less
cards. Contact cards are gold coated pins and contactless
cards communicates with radio frequency.
They are constructed from PVC polyester or polycarbonate.
Sensor are the electronic devices that sense the
Sensors are programmed using assembly language or C. Smart
sensors have computational, communication, and networking
Raj Kamal, Mobile Computing, Oxford
University Press, 2007
Amjad Umar, Mobile Computing and Wireless
Asoke Talukder,Roopa Yavagal, Mobile
Reza Behravanfar, Phillip Lindsay, Reza
B'Far, Mobile Computing Principles: