Introduction: Wireless PIR Sensor Alarm
This is a simple wireless PIR sensor alarm.The device consists of two parts.One is a transmitter that contains PIR sensor and a transmitter module.A second receiver consisting receiving module and piezo speaker. Test your PIR sensor before you made this with any code from internet.
Step 1: Parts
You need:
1. Two arduinos any version
2. PIR sensor
3. Piezo speaker
4: RF 433MHz or 315 MHz module
5. 10Kohm resistor
Step 2: Transmitter
This is code of transmitter. When PIR sensor detects human movement transmitter sends uppercase letter A. When pir sensor it holds no signal transmitter sends lowercase letter a.
int pirPin = 2;
int statePir = 0;
#include <VirtualWire.h>
void setup(){
Serial.begin(9600);
vw_setup(2000);
vw_set_tx_pin(3);
pinMode(pirPin,INPUT);
}
void loop(){
statePir = digitalRead(pirPin);
if (statePir == HIGH){
const char *msg = "A";
vw_send((uint8_t *)msg, strlen(msg));
vw_wait_tx();
}
if (statePir == LOW){
const char *msg = "a";
vw_send((uint8_t *)msg, strlen(msg));
vw_wait_tx();
}
}
Step 3: Receiver
Here is the code for receiver. Piezo play very loud alarm sound.
int led = 13;
int speaker = 10;
#define wait 1
#define time 100
int freq = 0;
#include
void setup(){
Serial.begin(9600); // Debugging only
vw_setup(2000);
vw_set_rx_pin(11);
vw_rx_start();
pinMode(speaker, OUTPUT);
pinMode(led, OUTPUT);
}
void loop(){
uint8_t buf[VW_MAX_MESSAGE_LEN];
uint8_t buflen = VW_MAX_MESSAGE_LEN;
if (vw_get_message(buf, &buflen))
{
for (int i = 0; i < buflen; i++)
{
if(buf[i] == 'A') {
digitalWrite(led, HIGH);
digitalWrite(speaker, HIGH);
for (freq = 500; freq < 3000; freq += 10)
{
tone(speaker, freq, time);
delay(wait);
}
for (freq = 3000; freq > 500; freq -= 10)
{
tone(speaker, freq, time);
delay(wait);
}
for (freq = 500;
freq < 3000;
freq += 10) //
{
tone(speaker, freq, time);
delay(wait);
}
for (freq = 3000;
freq > 500; freq -= 10)
{
tone(speaker, freq, time);
delay(wait);
}
for (freq = 500;
freq < 3000;
freq += 10) //
{
tone(speaker,
freq, time);
delay(wait);
}
for (freq = 3000;
freq > 500;
freq -= 10)
{
tone(speaker, freq, time);
delay(wait);
}
for (freq = 500; freq < 3000; freq += 10)
{
tone(speaker, freq, time);
delay(wait);
}
for (freq = 3000;
freq > 500; freq -= 10)
{
tone(speaker, freq, time);
delay(wait);
}
} if(buf[i] == 'a')
{ digitalWrite(led, LOW); digitalWrite(speaker, LOW);
}
}
}
}
Step 4: Library
For this project you need VirtualWire libraries. In the link below have all the files needed for this project. In video see how this work.
11 Comments
6 years ago
Hello
I time ago, i tried to do a similar mount but i hat the following problem on the emitter:
When the emitter send information - vw_send(...) - the Pir module stay in high mode even with no more mouvement .
But without emission the PIR can return to low.
I see that you put a 10k resistor in pull-up mode - is it to avoid the same problem ?
thanks.
7 years ago
Hello- could this be programmed to play a recording or cheering when trash is put into a trash can?
7 years ago
is there any alternative for rf module
8 years ago on Introduction
Is it possible to use multiple pir sensor and if is possible, how can we make the receiver know which transmitter transmit?
8 years ago on Introduction
for the virtualwire.h it must be version 1.9 otherwise it will not work on arduino 1.6.5
8 years ago on Introduction
and i want to add an ultrasonic sensor at receiver end to stop the alarm [ i want to make the alarm keeps making sound until someone stops it ] where should i change the code
8 years ago on Introduction
I am new at this , to implement this project what i will do about virtualwire.h , can you please explain that part ,
8 years ago on Introduction
Look like great project, I like the work you added in Wireless_PIR,rar. I think I will add this code into my Wireless Robot project.
Thanks for all your work, and sharing it.
8 years ago on Introduction
Very nice work. I love the little 433MHz modules.
8 years ago on Introduction
What would be the range of this?
Reply 8 years ago on Introduction
90 m in open range with 17.3cm antena