SparkFun PIR Breakout Hookup Guide

2024-09-10 | By SparkFun Electronics

License: See Original Project Arduino Raspberry Pi

Courtesy of SparkFun

Guide by El Duderino, Englandsaurus

Introduction

Looking to add some motion detection to a project you are working on? The SparkFun PIR ‎Breakout - 170uA (EKMC4607112K) and SparkFun PIR Breakout - 1uA (EKMB1107112) might be ‎just the thing! These breakouts use two versions of the EKM-series PIR sensors from ‎Panasonic^® to offer low profile motion-sensing options for both battery powered and continuously ‎powered applications.‎

Passive Infrared (PIR) sensors do not return specific distance data like distance sensors. Instead, ‎PIR sensors measure IR light coming from objects to detect motion in their field of view making ‎them perfect for motion-sensing applications such as turning devices like lights, cameras, motors, ‎etc. on automatically. The PIR sensors on these breakouts output a digital signal whenever a ‎moving object is detected in the sensing area. That signal can be monitored by a microcontroller to ‎trigger action on a connected device like those mentioned above.‎

If you would prefer to use these PIR sensors on an I²C bus, check out our Qwiic breakouts of ‎the 170uA PIR and 1uA PIR.‎

Required Materials

In order to follow along with this tutorial you'll need a few items along with your PIR Breakout. First, ‎you'll need a microcontroller or Single-Board Computer (SBC) like a Raspberry Pi or Jetson Nano to ‎monitor the PIR's signal:‎

You also may need some wire and headers to connect your breakout to your microcontroller. ‎Depending on your intended connections, you may want to use one or more of the following ‎connection and wire options:‎

Lastly, for easier testing of the range and detection area of your PIR Breakout installation, you may ‎want to have an LED or sound output like a buzzer to act as an indicator for when the sensor ‎detects motion.‎

Recommended Tools

We recommend soldering to the PTH header on the PIR Breakouts for the best connection. If you ‎do not have soldering tools and accessories, take a look at the following options:‎

Suggested Reading

PIR sensors are pretty straight-forward and a great entry point for novices with embedded ‎electronics and sensors but if you aren't familiar with the concepts covered in the tutorials linked ‎below, you may want to take a look through them before getting started with the SparkFun PIR ‎Breakout:‎

How to Solder: Through-Hole Soldering: This tutorial covers everything you need to ‎know about through-hole soldering.‎‎ ‎
What is an Arduino? What is this 'Arduino' thing anyway? This tutorial dives into what an ‎Arduino is and along with Arduino projects and widgets.‎
Logic Levels: Learn the difference between 3.3V and 5V devices and logic levels.‎
Raspberry Pi 4 Kit Hookup Guide: Guide for hooking up your Raspberry Pi 4 Model B ‎basic, desktop, or hardware starter kit together.‎

Hardware Overview

In this section we'll cover the characteristics and features of the PIR sensors on these breakouts.‎

Panasonic EKM-Series PIR Sensors

The EKMC4607112K and EKMB1107112 from Panasonic are low-profile PIR sensors ideal for ‎things like motion-activated lights, cameras, or other electronics. Applications include automatic ‎lighting for energy conservation, motion-activated security or trail cameras or maybe something fun ‎like a homemade convenience store chime (complete with a 100th customer celebration!). The ‎EKMC4607112K works best in a continuous power installation and has slightly better sensing ‎performance than the EKMB1107112 which is best suited for battery and low-power installations.‎

front_1

SparkFun PIR Breakout - 1µA Front

back_2

SparkFun PIR Breakout - 1µA Back

On each breakout we've broken the sensor's three pins (3V3/VDD, Ground and OUT) to a standard ‎‎0.1"-spaced PTH header for users to solder to. Take note that the sensors share the same PCB ‎design, and the version (1µA or 170µA) is marked by the solder pads "North" of the PIR.‎

The two PIR sensors have very similar electrical and sensing characteristics with a few specific ‎differences users will want to take note of prior to deciding which sensor is best for their situation. ‎The tables below outline the Electrical and Detection Performance Characteristics to give users a ‎basic overview. For a more detailed look at these two sensors, take a look at their respective ‎specification sheets: EKMC4607112K & EKMB1107112 along with the Panasonic PIR Sensors - ‎Product Brief (EKM-Series sensors are covered on page 8).‎

table_3

[1]

As we mentioned above, the sensing performances of the PIR Sensors are very similar with a few ‎notable differences you'll want to be aware of to decide which one works best for your application. ‎Also take note that PIR sensor performance can vary depending on the environment it is sensing.‎

Both the EKMC & EKMB have detection areas of 90° Horizontal and Vertical (±45°) and have 32 ‎detection zones. The table below outlines their detection performance in relation to the background ‎temperature:‎

table_4

‎[1] Note: Current consumption for the EKMB1107112 varies depending on the operating mode. ‎Refer to section 4-4 of the Spec Sheet for specific values.‎

Board Dimensions

The SparkFun PIR Breakout measures 0.50" x 0.85" (12.7mm x 21.59mm) and has one mounting ‎hole that fits a 4-40 screw.‎

dimensions_5

Hardware Assembly

Assembling the PIR Breakout circuit is pretty straight-forward since the board only has three pins. ‎Recommended setup requires some soldering so if you are not familiar with through-hole soldering ‎or want a refresher, we suggest reading through this tutorial:‎

howto_6

How to Solder: Through-Hole Soldering

This tutorial covers everything you need to know about through-hole soldering.‎

The demo circuit we'll assemble for the PIR Breakout uses a standard breadboard, M/M Jumper ‎Wires, and a SparkFun RedBoard Qwiic along with the SparkFun PIR and a set of breakaway male ‎headers - right angle.‎

For permanent installations, we recommend soldering wire directly to the PIR Breakout to create a ‎strong and stable connection to the sensor. For some tips on preparing and soldering wire, take a ‎look at this tutorial:‎

working_7

Working with Wire

How to strip, crimp, and work with wire.‎

To start off, we break off three pins from the set of breakaway male headers and solder them to the ‎PTH header on the PIR Breakout to have the sensor stand perpendicular to the breadboard for ‎easy testing.‎

start_8

Next, we plug the sensor into the breadboard (users connecting directly to their microcontroller can ‎ignore this step) taking care to orient it properly so the pins are not sharing the same rail. After the ‎PIR is in place, select three jumper wires and connect the PIR's pins to the matching pins on the ‎microcontroller. 3.3V to 3.3V, GND to Ground/GND and OUT to a digital I/O pin.‎

Note: If you choose to not use a dedicated 3.3V pin for your PIR (e.g an alternate voltage or a ‎digital pin) make sure the voltage it supplies falls within the operating voltage for the sensor:‎

EKMC4607112K: 3.0 to 6.0V
‎EKMB1107112: 2.3 to 4.0V‎

The OUT signal from the SparkFun PIR can also be used as an external interrupt to trigger an ‎interrupt event on a microcontroller. Users who wish to use the PIR as an external interrupt should ‎note which digital I/O pins on their microcontroller are interrupt-capable and connect the PIR's OUT ‎to one of those pins. For this example, we'll connect the OUT pin to a digital pin that is also ‎interrupt capable: D2.‎

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If you are using a Raspberry Pi or other SBC/development-board that uses Python as its primary ‎programming language, follow the above assembly steps for the PIR and connect it to your ‎Pi/SBC's GPIO header taking care to make the proper pin connections. Raspberry Pi users looking ‎for a quick GPIO reference can find one here or you can use the pinout command from the GPIO ‎Zero Python Library in the console to display the pinout there.‎

Arduino Examples

Now that our SparkFun PIR Breakout circuit is assembled it's time to upload some code to our ‎microcontroller to interact with the sensor. We'll cover three examples in this section to demonstrate ‎how to read the signal, stabilize it and use it as an external interrupt to trigger events on a ‎microcontroller.‎

Example 1 - Simple Read with Debounce

This quick and dirty example monitors the PIR output signal on D2 and uses the built-in LED on the ‎SparkFun RedBoard as a visual indicator whenever the PIR detects an object in it's field of view.‎

Copy the code below into a blank Arudino sketch, open the Tools menu to select your board (in ‎our case, Arduino Uno) and correct Port and click the "Upload" button:‎

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#define PIR_PIN 2   // PIR output on D2
#define LED_PIN  13  // LED to illuminate on motion
#define DEBOUNCE_TIME 750


void setup() 
{
  Serial.begin(115200); 
  // Set the PIR Output signal as an input for the microcontroller:
  pinMode(PIR_PIN, INPUT);

  // Configure the LED pin as an output
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW); // Turn the LED off

  // Wait for 30 seconds for the PIR to stabilize after power on:
  Serial.println("Waiting 30 Seconds while PIR warms up");
  for (uint8_t seconds = 0; seconds < 30; seconds++)
  {
    Serial.println(seconds);
    delay(1000);
  }
  Serial.println("PIR Warmed up.");
}

void loop() 
{
  // The PIR's output is active high
  int motionStatus = digitalRead(PIR_PIN);

  // If motion is detected, turn the onboard LED on and print an object was detected:
  if (motionStatus == HIGH) 
  {
    Serial.println("Object Detected!");
    digitalWrite(LED_PIN, HIGH);
    delay(DEBOUNCE_TIME);
  }
  else // Otherwise turn the LED off and print All Clear:
  {
    Serial.println("All clear!");
    digitalWrite(LED_PIN, LOW);
    delay(DEBOUNCE_TIME);
  }
}

After uploading, open the serial monitor and set your baud to 115200 to see the serial data. The ‎code will print out over serial any time the PIR detects motion in it' field of view and the D13 LED ‎should illuminate.‎

Example 2 - Interrupt

The Interrupt Example shows how to set up the output signal from the PIR as an external interrupt ‎to trigger an event on your microcontroller. This is particularly helpful for applications where you do ‎not want to constantly poll the digital pin the PIR's output is connected to so you can run other ‎loops in the background.‎

As we mentioned in the Hardware Assembly, this example assumes a SparkFun RedBoard/Arduino ‎Uno is used and uses D2 as the interrupt pin. If you are using a different microcontroller, adjust ‎the PIR_PIN definition to an interrupt-capable pin.‎

Copy the code below into a blank Arudino sketch, open the Tools menu to select your board (in ‎our case, Arduino Uno) and correct Port and click the "Upload" button:‎

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#define PIR_PIN 2 //Connect the output of the PIR to this pin
#define DEBOUNCE_TIME 750

bool pirStatus = false;
bool lastPirStatus = pirStatus;

void interruptRoutine() {
  pirStatus = digitalRead(PIR_PIN);
}

void setup() {
  Serial.begin(115200);
  pinMode(PIR_PIN, INPUT);
  attachInterrupt(digitalPinToInterrupt(PIR_PIN), interruptRoutine, CHANGE);

    // Wait for 30 seconds for the PIR to st abilize after power on:
  Serial.println("Waiting 30 Seconds while PIR warms up");
  for (uint8_t seconds = 0; seconds < 30; seconds++)
  {
    Serial.println(seconds);
    delay(1000);
  }
  Serial.println("PIR Warmed up. Starting readings");
}

void loop() {
  if (pirStatus != lastPirStatus) {
    if (pirStatus)
    {
      Serial.println("Object Detected");
    }
    else
    {
      Serial.println("Object Removed");
    }
    lastPirStatus = pirStatus;
  }
  delay(DEBOUNCE_TIME);
}

From here, you can modify the code so the interrupt event triggers whatever behavior you would ‎like. If you find the interrupt is firing too often, modify the code to trigger only on detected events ‎or by modifying the interrupt type to be either RISING or FALLING.‎

Python Example

Note: This example assumes you are using the latest version of Python 3. If this is your first time ‎using Python or GPIO hardware on a Raspberry Pi, please read through our Python Programming ‎with the Raspberry Pi guide and the Raspberry Pi GPIO Tutorial.‎

If you've assembled your SparkFun PIR Breakout circuit with a Raspberry Pi or other Python-based ‎development board, we've written a quick example to demonstrate how to read the PIR's output.‎

Example Dependencies

In order to interface with your Pi's GPIO ports your user must be a member of the gpio group. The pi user is a member by default. Users with sudo privileges can add users manually using the following command:

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sudo usermod -a -G gpio <username>

Simple Read

This example demonstrates reading the SIG output from the PIR sensor using digital reads. Copy ‎the code below into your preferred Python interpreter or into a blank text file and save it. If you are ‎using an interpreter like Thonny, you can run it from there. Otherwise, open the terminal and run it ‎by entering the following command: python3 FILENAME.py

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import time
import RPi.GPIO as GPIO
import sys

#Pin Definition
pir_pin = 4

#Set up pins and set PIR signal as an input
GPIO.setmode(GPIO.BCM)
GPIO.setup(pir_pin, GPIO.IN)

def run_example():

    #Wait 30 seconds for the PIR to stabilize

    print ("Waiting 30 seconds for PIR to stabilize")
    for i in range(0, 30):
        print(i)
        time.sleep(1)

    print ("Device Stable. Starting readings...")

    #Start monitoring the PIR output. If an object is detected, print "Object Detected" otherwise print "All Clear"

    while True:
        if GPIO.input(pir_pin):
            print("Object Detected")
        else:
            print("All clear")
        time.sleep(1)

if __name__ == '__main__':
    try:
        run_example()
    except (KeyboardInterrupt, SystemExit) as exErr:
        print("\nEnding Example")
        sys.exit(0)

Troubleshooting

Hopefully by following the steps in this guide you've got your SparkFun PIR Breakout up and ‎running monitoring motion and reporting data to your preferred microcontroller or single-board ‎computer. In case you run into any issues we've outlined a few tips and tricks for testing the PIR ‎here.‎

Hardware Check

Most common problems with the PIR Breakout revolve around the hardware connections. If your ‎PIR Breakout is not powering on or your microcontroller/SBC cannot detect the output signal from ‎the sensor, double-check your solder joints and your wiring to the microcontroller/SBC. ‎The Hardware Checks section of our Troubleshooting Tips guide can help you diagnose any ‎connection problems.‎

Detection Area/Field of View

The effective detection area of both the EKMC4607112K and EKMB1107112 is dependent on a ‎variety of factors. The specifications for measurement range are based on a target concept (area of ‎‎~700×250mm) of a human body moving across two detection zones at a speed of 1m/s. The PIR ‎senses objects best when moving across two detection zones on the horizontal (X) or vertical (Y) ‎axes. The PIR may struggle to detect objects moving away or toward the PIR (along the Z axis) ‎unless they also move along the other two axes.‎

Also note that background IR radiation can influence the PIR's ability to detect an object. The PIR ‎can detect objects with a larger temperature difference from the background at a larger range. ‎Refer back to the Hardware Overview section for specific ranges and temperature differences.‎

Take these detection limitations into consideration when selecting the mounting position of your ‎PIR Breakout. Section 4-7 of the sensors' spec sheets (EKMC4607112K and EKMB1107112) show ‎diagrams for optimal placement and object motion for sensing.‎

General Troubleshooting

If you need technical assistance and more information on this or another SparkFun product that is ‎not working as you expected, we recommend heading on over to the SparkFun Technical ‎Assistance page for some initial troubleshooting:‎

SPARKFUN TECHNICAL ASSISTANCE PAGE

If you don't find what you need there, the SparkFun Forums are a great place to find and ask for ‎help. If this is your first visit, you'll need to create a Forum Account to search product forums and ‎post questions.‎

Resources and Going Further

That's all for this Hookup Guide! For more information about the SparkFun PIR Breakout take a look ‎at the following links:‎