06-05-2013, 02:21 PM
A PROJECT REPORT ON ELECTRONIC SECURITY SYSYTEM
ELECTRONIC SECURITY.docx (Size: 1.49 MB / Downloads: 50)
• H-bridge motor driver l293d:-
• 600mA OUTPUT CURRENT CAPABILITY
• PER CHANNEL
• 1.2A PEAK OUTPUT CURRENT (non repetitive)
• PER CHANNEL
• ENABLE FACILITY
• OVERTEMPERATURE PROTECTION
• LOGICAL "0" INPUT VOLTAGE UP TO 1.5 V
• (HIGH NOISE IMMUNITY)
• INTERNAL CLAMP DIODES
DESCRIPTION:-
The Device is a monolithic integrated high voltage,high current four channel driver designed to accept standard DTL or TTL logic levels and drive inductive loads (such as relays solenoides, DC and stepping motors) and switching power transistors. To simplify use as two bridges each pair of channels is equipped with an enable input. A separate supply input is provided for the logic, allowing operation at a lower voltage and internal clamp diodes are included. This device is suitable for use in switching applications at frequencies up to 5 kHz.
• Liquid crystal display (16x2):-
When you start working with LCD modules you will start feeling the real power of MCUs and your
Imaginations will be touching sky you will wonder how many exciting powerful gadgets you can create and that’s so very easily.LCD Modules can present textual information to user. It’s like a cheap “monitor” that you can hook in all of your gadgets. They come in various types. The most popular one can display 2 lines of 16 characters. These can be easily interfaced to MCUs, thanks to the API (Functions used to easily access the modules) we provide. LCD interfacing is just fun!
Connection with board MINI:-
The LCD module can be easily connected to the Board™ MINI the connection is as follows. Connect the required pins of PORTC and PORTD as shown in the
diagram. The PORTs are clearly marked in the board. Connect to PORTD using a 8 PIN connecter and to PORTC using a 6 PIN connecter. Then supply the LCD using the onboard 5V supply output using a 2 PIN connecter. Leave D0-D4 of LCD unconnected. Note all the required connecters are provided with the kit.
• DC motor:-
Motors are one of the most common methods used to move robots around. They can be connected to gears and wheels and are a perfect way of adding mobility to your robot. There are many types of motor, and this tutorial will cover the main ones useful for robotics.
These are the most common and easy to use motor available. They are connected to a power supply by two wires. The direction of the motor shaft rotates can be changed by reversing the polarity (swap the positive and negative wires) of the motor supply voltage.
Unfortunately motors use quite a bit of current, so you can’t just plug them straight into your processor and expect them to work, the processor won't be able to supply the motor with enough current. We need to find a way of turning the motors on and off using the processor. This can be done by many methods, including transistors, relays or a motor driver chip. The Rob core contains two motor driver chips that can control up to 4 DC motors simultaneously. Connecting motors to the Rob core couldn't be simpler. Just connect the 2 wires of each motor to one of the motor outputs on the Rob core and your ready to go. The motor is controlled by 2 output pins on the processor, let’s say pin 1 and pin 2. The motors direction can be changed by different outputs of the pins. See table below
Capacitor:-
Fixed capacitors hold an electrical charge for a predetermined amount of time. The value of the capacitor is printed on the component. Smaller capacitors us a bit different system. Say it's marked with 104. That means it's a 10 with 4 zeros (104 = 100,000). Sometimes you'll see a "WV" after the voltage rating which means you can't use the capacitor with voltages exceeding this rating. You'll also find a polarity marking (- minus sign) that identifies the negative side of the capacitor and must be installed accordingly to prevent failure.
Diode:-
Diodes are made of either germanium or silicon. They carry two ratings: peak inverse voltage and current. These ratings are the maximum amount of each that a diode can handle. For instance, a 5 amp diode can only handle 5 amps before failure. They, like capacitors, have a marking (a cathode band) denoting the negative terminal. Light-emitting diodes (LED) emit infrared light, have a PIV rating of 100 to 150 volts, a maximum current rating of 40 milliamps, are powered in low-powered DC circuits of 12 volts or less, and are used with a resistor to limit the current.
Transistors:-
Transistors are divided into two catagories: signal, where they amplify a signal in things such as radios, telephones, etc., and power, where they switch a signal on or off in things such as motor drivers and power supplies. Size is usually a way to tell the two apart. Transistor are identified by a unique code, like 2N2222 or MPS6519, designating what kind of application they are for. To find this out, refer to a data book to locate the different characteristics and ratings. A signal transistor is small and can come in either a plastic or metal case. A power transistor is larger and always has a metal case to dissipate heat.
System Control and Reset:-
Resetting the AVR During Reset, all I/O Registers are set to their initial values, and the program starts execution from the Reset Vector. The instruction placed at the Reset Vector must be a JMP – absolute jump – instruction to the reset handling routine. If the program never enables an interrupt source, the Interrupt Vectors are not used, and regular program code can be placed at these locations. This is also the case if the Reset Vector is in the Application section while the Interrupt Vectors are in the Boot section or vice versa. The circuit diagram in Figure 15 shows the reset logic. Table 15 defines the electrical parameters of the reset circuitry.
The I/O ports of the AVR are immediately reset to their initial state when a reset source goes active. This does not require any clock source to be running.