Datasheet

page 34
v7
DS1820 is a digital temperature
sensor that uses 1-wire
®
interface for it’s operation. It is
capable of measuring temperatures
within the range of -55 to 128°C,
and provides ±0.5°C accuracy for
temperatures within the range of -10 to
85°C. It requires 3V to 5.5V power supply
for stable operation. It takes maximum
of 750ms for the DS1820 to calculate
temperature with 9-bit resolution.
1-wire
®
serial communication enables
data to be transferred over a single
communication line, while the process
itself is under the control of the master
microcontroller. The advantage of
such communication is that only one
microcontroller pin is used. Multiple
sensors can be connected on the same
line. All slave devices by default have
a unique ID code, which enables the
master device to easily identify all
devices sharing the same interface.
Board provides a separate socket (TS1)
for the DS1820. Communication line
with the microcontroller is selected using
SW11.3 DIP switch (ON position).
DS1820 - Digital
Temperature Sensor
DS1820
1
2 3 4 5 6 7 8
O
N
SW11
RA0
VCC-3.3V
R33
4K7
VCC
DQ
GND
VCC-3.3V
C41
100nF
DATA BUS
EasyPIC Fusion
™
v7 enables you to establish 1-wire
®
communication between
DS1820 and the microcontroller over RA0 pin. The connection is done placing
SW11.3 DIP switch to ON position (Figure 20-4). When placing the sensor in
the socket make sure that half-circle on the board silkscreen markings matches
the rounded part of the DS1820 sensor. If you accidentally connect the sensor
the other way, it may be permanently damaged. Make sure to disconnect other
peripherals, LEDs and additional pull-up or pull-down resistors from the interface
lines in order not to interfere with signal/data integrity.
Figure 20-4: DS1820
connected to RA0 pin
Enabling DS1820 Sensor
other modules
Figure 20-2:
DS1820 correctly
placed in socket
Figure 20-1:
DS1820
socket
Figure 20-3:
Enabled SW11.3
DIP switch