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Grove - PIR Motion Sensor

pir

This sensor allows you to sense motion, usually human movement in its range. Simply connect it to Grove - Base shield and program it, when anyone moves in its detecting range, the sensor will output HIGH on its SIG pin.

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Features

  • Grove compatible interface
  • Adjustable detecting distance
  • Adjustable holding time
tip
More details about Grove modules please refer to [Grove System](https://wiki.seeedstudio.com/Grove_System/)

Specification

ParameterValue/Range
Operating Voltage3V–5V
Operating Current(VCC = 3V)100uA
Operating Current(VCC = 5V)150uA
Measuring Range0.1 - 6m
Default detecting distance3m
Holding Time1 - 25s
Working Wave Length7 - 14um
Detecting Angle120 degrees

Platforms Supported

ArduinoRaspberry Pi

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caution
The platforms mentioned above as supported is/are an indication of the module's software or theoritical compatibility. We only provide software library or code examples for Arduino platform in most cases. It is not possible to provide software library / demo code for all possible MCU platforms. Hence, users have to write their own software library.

Getting Started

note
If this is the first time you work with Arduino, we firmly recommend you to see [Getting Started with Arduino](https://wiki.seeedstudio.com/Getting_Started_with_Arduino/) before the start.

Play With Arduino

Hardware

  • Step 1. Prepare the below stuffs:
Seeeduino V4.2Grove - PIR Motion SensorBase Shield

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pir

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  • Step 2. Connect Grove - PIR Motion Sensor to port D2 of Grove-Base Shield.

  • Step 3. Plug Grove - Base Shield into Seeeduino.

  • Step 4. Connect Seeeduino to PC via a USB cable.

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note
If we don't have Grove Base Shield, We also can directly connect Grove-PIR Motion Sensor to Seeeduino as below.
SeeeduinoGrove - PIR Motion Sensor
5VRed
GNDBlack
Not ConenctedWhite
D2Yellow

Software

  • Copy the code below into Arduino IDE and upload. If you do not know how to upload the code, please check how to upload code.
/*
macro definitions of PIR motion sensor pin
Use pin 2 to receive the signal from the module
*/
#define PIR_MOTION_SENSOR 2


void setup()
{
pinMode(PIR_MOTION_SENSOR, INPUT);
Serial.begin(9600);

}

void loop()
{
// If it detects moving people
// To know more about why digital numbers are used as boolean, check https://www.techtarget.com/whatis/definition/Boolean#:~:text=The%20Boolean%20data,1%20or%200
if(digitalRead(PIR_MOTION_SENSOR))
Serial.println("Hi,people is coming");
else
Serial.println("Watching");

delay(200);
}

note
The detecting distance and holding time can be adjusted by adding two extra potentiometers on board. For the details please refer to the V1.2 Eagle below. The module can also be set as re-triggerable or un-retriggerable by changing the jumper hat.

The result should be like:

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tip

Use a jumper cap to short two pins to trigger a repeatable or non-repeatable trigger, if you use GND, pin1 combination is non-repeatable trigger (default); pin1 and vcc is repeatable trigger. Non-repeatable trigger means in a cycle (probably a few seconds) on the departure of a single time, the wiki's case is non-repeatable trigger.

Play with Codecraft

Hardware

Step 1. Connect a Grove - PIR Motion Sensor to port D2 of a Base Shield.

Step 2. Plug the Base Shield to your Seeeduino/Arduino.

Step 3. Link Seeeduino/Arduino to your PC via an USB cable.

Software

Step 1. Open Codecraft, add Arduino support, and drag a main procedure to working area.

note
If this is your first time using Codecraft, see also [Guide for Codecraft using Arduino](https://wiki.seeedstudio.com/Guide_for_Codecraft_using_Arduino/).

Step 2. Drag blocks as picture below or open the cdc file which can be downloaded at the end of this page.

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Upload the program to your Arduino/Seeeduino.

tip
When the code finishes uploaded, the LED will goes on when people is coming.

Play With Raspberry Pi (With Grove Base Hat for Raspberry Pi)

Hardware

  • Step 1. Things used in this project:
Raspberry piGrove Base Hat for RasPiGrove - PIR Motion Sensor

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pir

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  • Step 2. Plug the Grove Base Hat into Raspberry.
  • Step 3. Connect the PIR motion sensor to port 12 of the Base Hat.
  • Step 4. Connect the Raspberry Pi to PC through USB cable.

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note
For step 3 you are able to connect the PIR motion sensor to **any GPIO Port** but make sure you change the command with the corresponding port number.

Software

  • Step 1. Follow Setting Software to configure the development environment.
  • Step 2. Download the source file by cloning the grove.py library.
cd ~
git clone https://github.com/Seeed-Studio/grove.py

  • Step 3. Excute below commands to run the code.
cd grove.py/grove
python grove_mini_pir_motion_sensor.py 12

Following is the grove_mini_pir_motion_sensor.py code.


import time
from grove.gpio import GPIO


class GroveMiniPIRMotionSensor(GPIO):
def __init__(self, pin):
super(GroveMiniPIRMotionSensor, self).__init__(pin, GPIO.IN)
self._on_detect = None

@property
def on_detect(self):
return self._on_detect

@on_detect.setter
def on_detect(self, callback):
if not callable(callback):
return

if self.on_event is None:
self.on_event = self._handle_event

self._on_detect = callback

def _handle_event(self, pin, value):
if value:
if callable(self._on_detect):
self._on_detect()

Grove = GroveMiniPIRMotionSensor


def main():
import sys

if len(sys.argv) < 2:
print('Usage: {} pin'.format(sys.argv[0]))
sys.exit(1)

pir = GroveMiniPIRMotionSensor(int(sys.argv[1]))

def callback():
print('Motion detected.')

pir.on_detect = callback

while True:
time.sleep(1)


if __name__ == '__main__':
main()

tip
If everything goes well, you will be able to see the following result

pi@raspberrypi:~/grove.py/grove $ python grove_mini_pir_motion_sensor.py 12
Motion detected.
Motion detected.
Motion detected.
^CTraceback (most recent call last):
File "grove_mini_pir_motion_sensor.py", line 84, in <module>
main()
File "grove_mini_pir_motion_sensor.py", line 80, in main
time.sleep(1)
KeyboardInterrupt

You can quit this program by simply press ++ctrl+c++.

Play With Raspberry Pi (with GrovePi_Plus)

Hardware

  • Step 1. Prepare the below stuffs:
Raspberry piGrovePi_PlusGrove - PIR Motion Sensor

pir

pir

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  • Step 2. Plug the GrovePi_Plus into Raspberry.

  • Step 3. Connect the sensor to D8 port of GrovePi_Plus.

  • Step 4. Connect the Raspberry to PC through USB cable.

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Software

tip
In this wiki we use the path **~/GrovePi/** instead of **/home/pi/Desktop/GrovePi**, you need to make sure Step 2 and Step 3 use the same path.
note
We firmly suggest you to update the firmware, or for some sensors you may get errors.
note
 If you are using **Raspberry Pi with Raspberrypi OS >= Bullseye**, you have to use this command line **only with Python3**.
  • Step 3. Git clone the Github repository.
cd ~
git clone https://github.com/DexterInd/GrovePi.git

  • Step 4. Run below commands to use the PIR Motion Sensor to monitor the movement of people.
cd ~/GrovePi/Software/Python
sudo python3 grove_pir_motion_sensor.py

Here is the grove_pir_motion_sensor.py code.

import time
import grovepi

# Connect the Grove PIR Motion Sensor to digital port D8
# SIG,NC,VCC,GND
pir_sensor = 8

grovepi.pinMode(pir_sensor,"INPUT")

while True:
try:
# Sense motion, usually human, within the target range
if grovepi.digitalRead(pir_sensor):
print 'Motion Detected'
else:
print '-'

# if your hold time is less than this, you might not see as many detections
time.sleep(.2)

except IOError:
print "Error"

The result should be like:

pi@raspberrypi:~/GrovePi/Software/Python $ sudo python3 grove_pir_motion_sensor.py

-
-
-
Motion Detected
Motion Detected
Motion Detected
Motion Detected
Motion Detected
Motion Detected
Motion Detected
Motion Detected
Motion Detected
Motion Detected
Motion Detected
-
-

FAQs

Q1: How to make the distance adjustable?

A1: R2: used to adjust the detecting distance(the AMP coefficient, 2MΩ). R6: used to adjust the holding time(the trigger duty, 100KΩ).

The detecting distance can be adjusted from 6 meters to only several centimeters. If the potentiometer is set to one end, the module will be too sensitive to be triggered by the atmosphere even there is no people moving before it. The holding time can also be adjusted by the Delay_time potentiometer, the value is about from 25s to 1s.

If R2 and R6 are soldered, please make sure R13 and R14 are empty.

note
There is risk that the board may be destroyed. Please think it over before making this modification.

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Schematic Online Viewer

Resources

Projects

Burglar Alarm with PIR Motion Sensor: This article explains Burglar Alarms with a PIR Motion Sensor.

Tech Support & Product Discussion

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