mikroElektronika EasyAVR v7, Руководство пользователя

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VO
UT
PB4
PA7
J19
D
AT
A BUS
VOUT
GND
VCC
C23
100nF
R3
3
10
0
Figure 15-5:
LM35
connected
to PA7 pin
The
LM35
is a low-cost precision
integrated-circuit temperature sensor,
whose output voltage is linearly
proportional to the Celsius (Centigrade)
temperature. The LM35 thus has an
advantage over linear temperature
sensors calibrated in ° Kelvin, as the
user is not required to subtract a large
constant voltage from its output to
obtain convenient Centigrade scaling.
It has a 10.0 mV/°C scale factor
and less than 60 μA current drain. As it
draws only 60 μA from its supply, it has
very low self-heating, less than 0.1°C
in still air. EasyAVR
™
v7 enables you
to get analog readings from the LM35
sensor in restricted temperature range
from +2ºC to +150ºC. Board provides
a separate socket (
TS2
)
for the LM35 sensor in
TO-92 plastic packaging.
Readings are done with
microcontroller using single
analog input line, which is
selected with jumper
J19
. Jumper
connects the sensor with either
PA7
or
PB4
microcontroller pins.
EasyAVR
™
v7 enables you to get analog readings from the LM35 sensor using
PA7
or
PB4
microcontroller pins. The selection of either of those two lines
is done using
J19
jumper. When placing the sensor in the socket make sure
that half-circle on the board’s silkscreen markings matches the rounded part of
the LM35 sensor. If you accidentally connect the sensor the other way, it can
be permanently damaged and you might need to replace it with another one.
During the readings of the sensor, make sure that no other device uses the
selected analog line, because it may interfere with the readings.
Figure 15-1:
LM35 not
connected Figure 15-2:
LM35 placed
in socket Figure 15-3:
LM35
connected
to PB4 pin Figure 15-4:
LM35
connected
to PA7 pin
Enabling LM35 Sensor
LM35 - Analog
Temperature Sensor
page 25
1 2 3 4
modules
Easy AVR
v7