Arduino uno User Manual

-
void loop() {
-
if (pir.motion_detected()) {
-
Serial.println("Motion detected");
25
} else {
-
Serial.println("No motion detected");
-
}
-
delay(200);
-
}
30
With the constant PIR_INPUT_PIN , you can define the digital pin you’ve connected
your PIR sensor to. In line 4, we begin the definition of a class named Passive-
InfraredSensor that encapsulates all things related to PIR sensors.
We define a member variable named _input_pin that stores the number of the
digital pin we’ve connected our sensor to. Then we define a constructor that
expects the pin number as an argument and assigns it to our member variable.
The only method we need to define is motion_detected . It returns true if it has
currently detected a motion and false otherwise. So, it has to check only
whether the current state of the sensor’s digital pin is HIGH or LOW .
Compile the sketch and upload it to your Arduino. You should see an output
similar to the following screenshot when you start to wave your hand in front
of the sensor.
Now we’ve built the two main components of our burglar alarm, and the only
thing left to do is to bring them both together. We’ll do that in the next section.
Chapter 11. Creating a Burglar Alarm with Email Notification • 196
report erratum • discuss
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