solar operated rolling display

SOLAR OPERATED ROLLING DISPLAY

Objective:
The objective of this project is to construct the solar operated rolling LED display.
Scope:
This project is used to display and scroll the alphabets and numbers on the scrolling display using microcontroller with solar charged battery power supply with help of solar panel.
Brief methodology:
This project is designed with
• Microcontroller
• Solar panel
• Matrix keypad
• Rolling Led display
• 12V Battery Power Supply
In this project solar panel is used for charging the battery for power supply to th controller and the Rolling led display. And the matrix keypad is used to set the alphabets and numbers for scrolling on the display.
The Microcontroller is connected to the rolling display through the serial communication.
The matrix keypad is connected to the controller. The selected alphabets and numbers are temporally stored on the controller.If any changes in the selected letters, we can correct using this matrix keypad. The Battery voltage is given to the rolling led and microcontroller through the Regulator

MICROCONTROLLER
1.PIN DIAGRAM: IC-AT89S52

2. PIN DETAILS:
Pin Number Description
1 - 8 P1.0 - P1.7 - Port 1
9 RST - Reset
10 - 17 P3.0 - P3.7 - Port 3
18 XTAL2 - Crystal
19 XTAL1 - Crystal
20 GND - Ground
21 - 28 P2.0 - P2.7 - Port 2
29 PSEN - Program Store Enable
30 ALE - Address Latch Enable
31 EA - External Access Enable
32 - 39 P0.7 - P0.1 - Port 0
40 Vcc - Positive Power Supply

3. PIN DESCRIPTION:

3.1 VCC
Supply voltage.
3.2 GN
Ground.
3.3 Port 0
Port 0 is an 8-bit open drain bidirectional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high-impedance inputs.
Port 0 can also be configured to be the multiplexed low-order address/data bus during accesses to external program and data memory. In this mode, P0 has internal pull-ups.
Port 0 also receives the code bytes during Flash programming and outputs the code bytes during program verification. External pull-ups are required during program verification.
3.4 Port 1
Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled high by the internal pull-ups and can be used as inputs.
As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. In addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count input (P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX), respectively, as shown in the following table.
Port 1 also receives the low-order address bytes during Flash programming and verification.
3.5 Port 2
Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to
Port 2 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups.
Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX @ DPTR). In this application, Port 2 uses strong internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register.

3.6 Port 3
Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pull-ups. Port 3 receives some control signals for Flash programming and verification.
Port 3 also serves the functions of various special features of the AT89S52, as shown in the following table.
3.7 RST
Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. This pin drives high for 98 oscillator periods after the Watchdog times out. The DISRTO bit in SFR AUXR (address 8EH) can be used to disable this feature. In the default state of bit DISRTO, the RESET HIGH out feature is enabled.
3.8 ALE/PROG
Address Latch Enable (ALE) is an output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation, ALE is emitted at a constant rate of 1/6 the oscillator frequency and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external data memory.
If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.

SOLAR PANEL

A solar panel is a set of solar photovoltaic modules electrically connected and mounted on a supporting structure. A photovoltaic module is a packaged, connected assembly of solar cells. The solar module can be used as a component of a larger photovoltaic system to generate and supply electricity in commercial and residential applications. Each module is rated by its DC output power under standard test conditions (STC), and typically ranges from 100 to 320 watts. The efficiency of a module determines the area of a module given the same rated output an 8% efficient 230 watt module will have twice the area of a 16% efficient 230 watt module. A single solar module can produce only a limited amount of power; most installations contain multiple modules. A photovoltaic system typically includes a panel or an array of solar modules, an inverter, and sometimes a battery and/or solar tracker and interconnection wiring.

ADVANTAGES:
• Solar energy is free although there is a cost in the building of ‘collectors’ and other equipment required to convert solar energy into electricity or hot water.
• Solar energy does not cause pollution. However, solar collectors and other associated equipment / machines are manufactured in factories that in turn cause some pollution.
• Solar energy can be used in remote areas where it is too expensive to extend the electricity power grid.
• Many everyday items such as calculators and other low power consuming devices can be powered by solar energy effectively.
• It is estimated that the worlds oil reserves will last for 30 to 40 years. On the other hand, solar energy is infinite (forever).
KEYPAD

A numeric keypad, or numpad for short, is the small, palm-sized, seventeen key section of a computer keyboard, usually on the very far right.
The numeric keypad features digits 0 to 9, addition (+), subtraction (-), multiplication(*) and division (/) symbols, a decimal point (.) and Num Lock and Enter keys.
Laptop keyboards often do not have a numpad, but may provide numpad input by holding a modifier key (typically lapelled "Fn") and operating keys on the standard keyboard.
Particularly large laptops (typically those with a 17 inch screen or larger) may have space for a real numpad, and many companies sell separate numpads which connect to the host laptop by a USB connection.
Numeric keypads usually operate in two modes: when Num Lock is off, keys 8, 6, 2, 4 act like an arrow keys and 7, 9, 3, 1 act like Home, PgUp, PgDn and End; when Num Lock is on, digits keys produce corresponding digits. These, however, differ from the numeric keys at the top of the keyboard in that, when combined with the Alt key on a PC, they are used to enter characters which may not be otherwise available: for example, Alt-0169 produces the copyright symbol. These are referred to as Alt codes.
On Apple Computer Macintosh computers, which lack a Num Lock key, the numeric keypad always produces only numbers. The num lock key is replaced by the clear key.
Numeric keypads usually operate in two modes: when Num Lock is off, keys 8, 6, 2, 4 act like an arrow keys and 7, 9, 3, 1 act like Home, PgUp, PgDn and End; when Num Lock is on, digits keys produce corresponding digits. ROLLING LED DISPLAY

An LED display is a flat panel display, which uses an array of light-emitting diodes as a video display. An LED panel is a small display, or a component of a larger display. They are typically used outdoors in store signs and billboards, and in recent years have also become commonly used in destination signs on public transport vehicles or even as part of transparent glass area. LED panels are sometimes used as form of lighting, for the purpose of general illumination, task lighting, or even stage lighting rather than display.
LED text displays: LED text displays refer to types that are specialized and limited to display of alpha-numeric characters. Most types display either one character or a group of characters. One character is generally displayed by a matrix of LEDs, or by a matrix of segments.
Basic advantages of LED Light:
1. Energy efficient - LED’s are now capable of outputting 135 lumens/watt
2. Long Lifetime - 50,000 hours or more if properly engineered
3. Rugged - LED’s are also called “Solid State Lighting (SSL) as they are made of solid material with no filament or tube or bulb to break
4. No warm-up period - LED’s light instantly – in nanoseconds
5. Not affected by cold temperatures - LED’s “like” low temperatures and will startup even in subzero weather
6. Directional - With LED’s you can direct the light where you want it, thus no light is wasted
7. Excellent Color Rendering - LED’s do not wash out colors like other light sources such as fluorescents, making them perfect for displays and retail applications
BATTERY

An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy.[1] Since the invention of the first battery (or "voltaic pile") in 1800 by Alessandro Volta, batteries have become a common power source for many household and industrial applications
There are two types of batteries: primary batteries (disposable batteries), which are designed to be used once and discarded when they are exhausted, and secondary batteries (rechargeable batteries), which are designed to be recharged and used multiple times. Miniature cells are used to power devices such as hearing aids and wristwatches; larger batteries provide standby power for telephone exchanges or computer data centers.
Advantages of batteries:
• No need to be connected to an electrical system which is preferable in some cases.
• Most things that run on batteries are portables.
• It can be used in areas where electricity is not provided.
• It can be easily replaced.