Arduino uno User Manual

The PIR sensor has three pins: power, ground, and signal. Connect power to
the Arduino’s 5V supply, ground to one of the Arduino’s GND pins, and signal
to digital pin 2. In the following figure, you see a circuit diagram that connects
a PIR sensor from Adafruit
7
to an Arduino. Note that PIR sensors from different
vendors often differ in the order of their connectors. The PIR sensor in Figure
29, Top and bottom of a passive infrared sensor, is different, so you should
always make sure you connect the correct pins.
The PIR sensor usually also has a jumper that you can use for changing its
behavior. For our project, it has to be in position H; the jumper has to cover
the pin next to the H. (Lady Ada has an excellent tutorial on PIR sensors.)
8
Then enter the following code in the Arduino IDE:
Ethernet/MotionDetector/MotionDetector.ino
const unsigned int PIR_INPUT_PIN = 2;
Line 1
const unsigned int BAUD_RATE = 9600;
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class PassiveInfraredSensor {
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int _input_pin;
5
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public:
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PassiveInfraredSensor(const int input_pin) {
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_input_pin = input_pin;
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pinMode(_input_pin, INPUT);
10
}
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const bool motion_detected() const {
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return digitalRead(_input_pin) == HIGH;
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}
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};
15
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PassiveInfraredSensor pir(PIR_INPUT_PIN);
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void setup() {
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Serial.begin(BAUD_RATE);
20
}
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7. http://www.adafruit.com/products/189
8. https://learn.adafruit.com/pir-passive-infrared-proximity-motion-sensor
report erratum • discuss
Detecting Motion Using a Passive Infrared Sensor • 195
www.it-ebooks.info

Arduino uno Specifications

General

Form factor	Arduino
Certification	RoHS, FC, CE
Processor model	-
Processor frequency	- MHz
Microcontroller model	ATmega328
Microcontroller frequency	16 MHz
DC input voltage	7-12 V
Operating voltage	5 V
DC current per I/O pin	40 mA
Flash memory	0.032 MB
Maximum internal memory	- GB
SRAM (Static Random Access Memory)	2 KB
EEPROM (Electrically Erasable Programmable Read-Only Memory)	1 KB
Wi-Fi	No
Number of analog I/O pins	6
Number of digital I/O pins	14

Weight and Dimensions

Board dimensions	53.4 x 68.6 mm