mikroElektronika EasyPIC v7, Руководство пользователя

Страница: 29 / 37

Easy PIC
for dsPIC30
®
v7
page 29
J13
RB8
RB10
D
AT
A BUS
Figure 16-5:
LM35 connected to RB8
microcontroller 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. EasyPIC
™
v7 for dsPIC30
®
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 J13. Jumper
connects the sensor with either PB8 or
PB10 microcontroller pins.
EasyPIC
™
v7 for dsPIC30
®
enables you to get analog readings from the LM35
sensor using RB8 or RB10 microcontroller pins. The selection of either of those
two lines is done using J13 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 sensor readings make sure that no other device is using the
selected analog line, as that may interfere with the readings.
Figure 16-1:
LM35 not
connected Figure 16-2:
LM35 placed
in socket Figure 16-3:
LM35
connected
to RB8 pin Figure 16-4:
LM35
connected
to RB10 pin
Enabling LM35 Sensor
LM35 - Analog
Temperature Sensor
1 2 3 4
other modules