The document explains sensors as devices that convert physical parameters into signals for processing, highlighting their essential role in automation across various applications. It outlines criteria for sensor selection and categorizes them into types, including environmental and motion sensors with specific examples like temperature and humidity sensors. Additionally, it provides basic instructions for interfacing and programming these sensors with microcontrollers.

2. What are sensors???
A device which provides a usable output in response to
a specified measurand.
A sensor acquires a physical parameter
and converts it into a signal suitable for
processing (e.g. optical, electrical,
mechanical).
Real
world
Senso
r
Intelligent
system

3. Working:
Physical quantity
Electrical Signals
Microcontroller

4. Need for Sensors
 Sensors are omnipresent. They embedded
in our bodies, automobiles, airplanes,
cellular telephones, radios, chemical plants,
industrial plants and countless other
applications.
 Without the use of sensors, there would be
no automation !!

5. Criteria to choose a sensor:
1.Accuracy
2.Environmental Condition
3.Range
4.Resolution
5.Cost
6.Sensitivity
7.Availability
8.Lifetime

6. Types of Robotics sensors:
1. Environment sensors
2. Motion sensors
3. Touch sensors
4. Proximity sensors
5. IR sensors

7. Environmental sensors:
1.Temperature Sensors:
Temperature sensors appear in building, chemical
process plants, engines, appliances, computers, and many
other devices that require temperature monitoring
2.Pressure Sensors:
A pressure sensor measures pressure, typically of gases
or liquids.
3.Humidity Sensors:
Humidity sensing is very important in control systems
for industrial processes and human comfort.

8. Circuit diagram of IR sersor:

9. I R led
Photodiode
I R SENSOR
-
OPAMP
POT
GND
TO
MICROCONTROLLER
PIN
(LOGIC1)
1
+
vcc
Black line

10. I R led Photodiode
I R SENSOR
-
OPAMP
POT
GND
0
+
White line line
TO
MICROCONTROLLER
PIN
(LOGIC 0)
vcc

11. Instructions
 bit_is_set(PINx , Pin no.);
 bit_is_clear(PINx , Pin no.);
 Header File:
compat/deprecated.h

13. Before going into programming mode
lets learn to interface SWITCH :
 Instructions :
1. sbi(PORTX , Pin no.);
2. cbi(PORTX , Pin no.);
Ex : sbi ( PORTD, 7);
cbi ( PORTD, 7);
1. bit_is_set(PINX ,Pin no.);
2. bit_is_clear(PINX ,Pin no.);
Ex: bit_is_set(PIND,2);
bit_is_clear(PIND,2);
VCC
D2
VCC

14. Program:
 #define F_CPU 16000000
 #include <avr/io.h>
 #include <util/delay.h>
 #include<compat/deprecated.h>
int main(void)
 {
 DDRD=0b11110000;
 PORTD=0b00001111;
 while(1)
 {
 if(bit_is_clear(PIND,2))
 sbi(PORTD,6);
else
if(bit_is_clear(PIND,3))
sbi(PORTD,7);
else
cbi(PORTD,6);
cbi(PORTD,7);
}
}

15. else if(bit_is_clear(PIND,3))
sbi(PORTD,7);
else
cbi(PORTD,6);
cbi(PORTD,7);
}
}