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European Association for the Development of Renewable
Energies, Environment and Power Quality (EA4EPQ)

International Conference on Renewable Energies and Power Quality
(ICREPQ’10)
Granada (Spain), 23rd to 25th March, 2010

Microcontroller-Based Moving Message Display Powered by Photovoltaic
Energy
F. H. Fahmy, S. M. Sadek, N. M. Ahamed, M. B. Zahran, and Abd El-Shafy A. NafehElectronics Research Institute, PV Dept., NRC Building, El-Tahrir St., Dokki, 12311-Giza, Egypt Tel./Fax+20233310512/33351631
Ninet321@yahoo.com, mbazahran_2007@yahoo.com, abdelshafyn@yahoo.com

Abstract.
The aim of this paper is to design a textual display
system, based on a light emitting diode (LED) dot matrix
array powered by solar energy. The paper involves taking
the device from an initialconcept, through a design phase,
to constructing a prototype of the product. The system
consists of the display unit, which is powered from a
photovoltaic ( PV) module and a solar sealed lead acid
battery.. The self-contained nature of the intended design
will allow the display to be mounted almost anywhere it is
needed. Therefore, the main purpose of this paper is to
utilize the solar energyand a rechargeable battery to
power a universal self-contained characters display unit.
This display unit is useful for creating attention-getting
messages, location identifiers such as maps and address
identification display modules. The implementation of a
moving message display panel which displays a text
containing 22 characters (i.e., PHOTOVOLTAIC
DEPARTMENT), and is powered by a PVmodule has
been achieved. The control of this panel is based on an
Atmega 8515 a Microcontroller. The used Atmel
Microcontroller is programmed using Assembly language,
through using AVR studio software and STK500 kit. The
photovoltaic module charges the battery during the day
and the battery is continuously feeds the display panel.
The system consists of a single PV module that produces
75watt, a rechargeable battery (12 V, 100 Ah), a charging
battery controller with an extra regulator circuit (that can
produce 5 V , 1.5 A to feed the display panel and
microcontroller )
and moving message dot matrix
display panel with its rows and columns drivers.
(Atmega8515 microcontroller, dot-matrices, rows and
columns drivers). The advantages of the designed display
system is easy toset up, program and handle, it also
allows the outlet to simply and clearly present the scrolled
text. Finally, it is found that the designed system is suited
to be used for many other applications.
Keywords
Solar cells, microcontroller, moving message unit, PV
sizing and charge controller.

1. Introduction
As the energy demands around the world increase,
the need to alternative energysources is increased.
Therefore, it must exploit new and renewable sources of

energy (e.g. solar energy, wind, hydrogen geothermal
….etc.) [1].
Solar energy is a renewable energy source that is
environmentally friendly, unexhausted and unlike fossil
fuels, solar energy is available just about everywhere on
earth and this source of energy is free. Stand-alone
photovoltaic (PV) systems aredesigned to operate,
independent of electric utility grid. They are excellent for
remote applications where utility grid is inaccessible and
in locations where significant connection cost makes grid
power prohibitively expensive. Such applications include
parking, emergency telephones, temporary traffic signs,
and remote guard posts and signals. Also, PV systems are
generally designed andsized to supply certain. DC and/or
AC electrical loads. Stand – alone PV system with battery
backup can supply power to electrical loads with
availability about 100% during all the operating
environmental conditions. PV systems are generally
designed so that there is a deficit in energy in winter, but
a surplus in summer. This deficit and surplus can lead,
respectively, to over discharging...