25-05-2012, 10:37 AM
PROPELLER LED DISPLAY
[attachment=22949]
ABSTRACT
Conventional methods of displaying images to public are using LCD display and
dot-matrix LED board. Propeller LED display is a device that project an image or time
as if the images are floating in the air. The floating image is received because of human
eye limitation. Actually the floating images emerge by synchronizing LED'S blink to
form an image at particular time and rate.
The programming of PIC is using Assembly Language. This project consist two
main circuit; motor controller circuit and LED circuit. 9VDC will be used to supply the
power for motor controller circuit. Then the motor controller circuit will provides power
to LED circuit and DC motor. When DC motor is rotating, the floating image will
appear. The synchronization of DC motor speed and LED blink cause the image visible
to human eyes. So the desired image such as clock, date or symbol can be programmed
and displayed.
INTRODUCTION
1.1 PROJECT SYNOPSIS
Nowadays, there are so many way to displaying a message such as using 7
segment, Frosted Light Bar (RGB 16.7 millions true colows), digital clock and etc.
These kind of device are used to advertise or displaying some sort of message in
order to attract people. It is different than a conventional method such as poster,
banner and etc. These projects are cheaper, easier and even carry out the same
purpose as any display apparatus.
1.2 PROBLEM STATEMENTS
From other article and project, there are some problems which are effected
the outcome of the image displayed. The main problem is concerning the motor. A
VCR motor has to be used as a motor in order to prevent noise. The circuit also have
to use photo transistor to generate precise index pulse. In order to display the date
and clock, the circuit must have memory capacitor to keep the clock ticking even
when the power is not supplied to the circuit. The memory capacitor is expensive
plus, it bigger and heavy. To replace the memory capacitor, a small, cheap and light
3V lithium battery is used as a replacement. A voltage regulator also has to be used
in order to allow rotation speed change without effecting the circuit and displayed
images.
COMPONENT AND SOFTWARE EXPLANATION
The PIC16F84A is a high-performance, low-cost, CMOS, fully-static 8-bit
microcontroller with 1K x 14 EEPROM program memory and 64 bytes of EEPROM
data memory. It is the second member of an enhanced family of PICl6CXX
microcontrollers.
Its high performance is due to instructions that are all single word (14-bit
wide), which execute in single cycle (400 ns at lOMHz clock) except for programbranches
which take tow cycles (800ns). The PIC16C84 has four interrupt sources
and an eight level hardware stack. The peripherals include an 8-bit timerlcounter
with an 8- bit prescaler (effectively a 16 bit timer) and 13 bi- directional I10 pins.
The high current drive (25 mA max. sink, 20 mA max source) of the I10 pins help
reduce external drivers and therefore, system cost. The PIC16C84 product is
supported by an assembler, an in-circuit emulator and a production quality
programmer. These tools are supported on the IBM PC and compatible machines.
[attachment=22949]
ABSTRACT
Conventional methods of displaying images to public are using LCD display and
dot-matrix LED board. Propeller LED display is a device that project an image or time
as if the images are floating in the air. The floating image is received because of human
eye limitation. Actually the floating images emerge by synchronizing LED'S blink to
form an image at particular time and rate.
The programming of PIC is using Assembly Language. This project consist two
main circuit; motor controller circuit and LED circuit. 9VDC will be used to supply the
power for motor controller circuit. Then the motor controller circuit will provides power
to LED circuit and DC motor. When DC motor is rotating, the floating image will
appear. The synchronization of DC motor speed and LED blink cause the image visible
to human eyes. So the desired image such as clock, date or symbol can be programmed
and displayed.
INTRODUCTION
1.1 PROJECT SYNOPSIS
Nowadays, there are so many way to displaying a message such as using 7
segment, Frosted Light Bar (RGB 16.7 millions true colows), digital clock and etc.
These kind of device are used to advertise or displaying some sort of message in
order to attract people. It is different than a conventional method such as poster,
banner and etc. These projects are cheaper, easier and even carry out the same
purpose as any display apparatus.
1.2 PROBLEM STATEMENTS
From other article and project, there are some problems which are effected
the outcome of the image displayed. The main problem is concerning the motor. A
VCR motor has to be used as a motor in order to prevent noise. The circuit also have
to use photo transistor to generate precise index pulse. In order to display the date
and clock, the circuit must have memory capacitor to keep the clock ticking even
when the power is not supplied to the circuit. The memory capacitor is expensive
plus, it bigger and heavy. To replace the memory capacitor, a small, cheap and light
3V lithium battery is used as a replacement. A voltage regulator also has to be used
in order to allow rotation speed change without effecting the circuit and displayed
images.
COMPONENT AND SOFTWARE EXPLANATION
The PIC16F84A is a high-performance, low-cost, CMOS, fully-static 8-bit
microcontroller with 1K x 14 EEPROM program memory and 64 bytes of EEPROM
data memory. It is the second member of an enhanced family of PICl6CXX
microcontrollers.
Its high performance is due to instructions that are all single word (14-bit
wide), which execute in single cycle (400 ns at lOMHz clock) except for programbranches
which take tow cycles (800ns). The PIC16C84 has four interrupt sources
and an eight level hardware stack. The peripherals include an 8-bit timerlcounter
with an 8- bit prescaler (effectively a 16 bit timer) and 13 bi- directional I10 pins.
The high current drive (25 mA max. sink, 20 mA max source) of the I10 pins help
reduce external drivers and therefore, system cost. The PIC16C84 product is
supported by an assembler, an in-circuit emulator and a production quality
programmer. These tools are supported on the IBM PC and compatible machines.