1
Design of the Temperature Control System Based on AT89C51
ABSTRACT
The
principle
and
functions
of
the
temperature
control
system
based
on
micro
controller AT89C51 are studied, and the temperature measurement unit consists of the
1-Wire
bus
digital
temperature
sensor
DS18B20.
The
system
can
be
expected
to
detect the preset temperature, display time and save monitoring data. An alarm will be
given
by
system
if
the
temperature
exceeds
the
upper
and
lower
limit
value
of
the
temperature which can be set discretionarily and then automatic control is achieved,
thus
the
temperature
is
achieved
monitoring
intelligently
within
a
certain
range.
Basing
on
principle
of
the
system,
it
is
easy
to
make
a
variety
of
other
non-linear
control systems so long as the software design is reasonably changed. The system has
been proved to be accurate, reliable and satisfied through field practice.
KEYWORDS: AT89C51; micro controller; DS18B20; temperature
1
INTRODUCTION
Temperature
is
a
very
important
parameter
in
human
life.
In
the
modern
society, temperature control (TC) is
not
only used in
industrial production, but
also
widely used in other fields. With the improvement of the life quality, we can find the
TC appliance in hotels, factories and home as well. And the trend that TC will better
serve
the
whole
society,
so
it
is
of
great
significance
to
measure
and
control
the
temperature.
Based
on
the
AT89C51
and
temperature
sensor
DS18B20,
this
system
controls
the
condition
temperature
intelligently.
The
temperature
can
be
set
discretionarily
within
a
certain
range.
The
system
can
show
the
time
on
LCD,
and
save monitoring data; and automatically control the temperature when the condition
temperature
exceeds
the
upper
and
lower
limit
value.
By
doing
so
it
is
to
keep
the
temperature unchanged.
The system is
of high anti-jamming, high control
precision
and flexible design; it also fits the rugged environment. It is mainly used in people's
life to improve the quality of the work and life. It is also versatile, so that it can be
convenient to extend the use of the system. So the design is of profound importance.
The general design, hardware design and software design of the system are covered.
1.1 Introduction
The 8-bit AT89C51 CHMOS microcontrollers are designed to handle high-speed
calculations and fast input/output operations. MCS 51 microcontrollers are typically