I have a PIR sensor attached to a Amica nodeMCU board routing 5v from VIN and attached via USB port for testing. When motion is deteted it connects to the internet and sends data to IFTTT which i receive a notification on my phone.
When I power up, the PIR pauses for calibration and then immediately goes HIGH and fires the motion detected call which i receive on my phone. However From then on it never goes LOW but every 5-8 minutes sends another HIGH call through even if there is no motion.
Testing
My Code modified version of Arduino Playground PIR Project
//Sends IFTTT every 5 minutes it detects motion
#include <ESP8266WiFi.h>
//WiFi Settings
// Set up macros for wifi and connection.
#define SSID "my-network" // SSID
#define PASS "mypassphrase" // Network Password
#define HOST "maker.ifttt.com" // Webhost
//-------------------------------
const char* streamId = "test";
const char* privateKey = "mysecretkey";
//PIR Settings
//the time we give the sensor to calibrate (10-60 secs according to the datasheet)
int calibrationTime = 10;
//the time when the sensor outputs a low impulse
long unsigned int lowIn;
//the amount of milliseconds the sensor has to be low
//before we assume all motion has stopped
long unsigned int pause = 5000;
int interval = 1000; // Wait between dumps
boolean lockLow = true;
boolean takeLowTime;
int ledPin = 1;
int pirPin = 2; //the digital pin connected to the PIR sensor's output
int nPIR_detect;
int motion = 2;
int minSecsBetweenUpdates = 300; // 5 minutes
long lastSend = -minSecsBetweenUpdates * 1000l;
//-------------------------------
// Begin Setup
void setup(){
Serial.begin(115200);
pinMode(pirPin, INPUT);
digitalWrite(pirPin, LOW);
//give the sensor some time to calibrate
Serial.print("calibrating sensor ");
for(int i = 0; i < calibrationTime; i++){
Serial.print(".");
delay(1000);
}
Serial.println(" done");
Serial.println("SENSOR ACTIVE");
delay(50);
nPIR_detect = 0;
// Test ESP8266 module.
Serial.println("AT");
delay(5000);
if(Serial.find("OK")){
connectWiFi();
}
}
void loop(){
if(digitalRead(pirPin) == HIGH){
digitalWrite(BUILTIN_LED, HIGH); //the led visualizes the sensors output pin state
if(lockLow){
//makes sure we wait for a transition to LOW before any further output is made:
lockLow = false;
Serial.println("---");
Serial.print("motion detected at ");
Serial.print(millis()/1000);
Serial.println(" sec");
sendData(String(motion));
delay(50);
}
takeLowTime = true;
}
if(digitalRead(pirPin) == LOW){
digitalWrite(BUILTIN_LED, LOW); //the led visualizes the sensors output pin state
if(takeLowTime){
lowIn = millis(); //save the time of the transition from high to LOW
takeLowTime = false; //make sure this is only done at the start of a LOW phase
}
//if the sensor is low for more than the given pause,
//we assume that no more motion is going to happen
if(!lockLow && millis() - lowIn > pause){
//makes sure this block of code is only executed again after
//a new motion sequence has been detected
lockLow = true;
Serial.print("motion ended at "); //output
Serial.print((millis() - pause)/1000);
Serial.println(" sec");
delay(50);
}
}
}
void sendData(String motion){
//Send the motion to IFTTT value1
Serial.print("connecting to ");
Serial.println(HOST);
// Use WiFiClient class to create TCP connections
WiFiClient client;
const int httpPort = 80;
if (!client.connect(HOST, httpPort)) {
Serial.println("connection failed");
return;
}
// We now create a URI for the request
String url = "/trigger/";
url += streamId;
url += "/with/key/";
url += privateKey;
url += "?value1=";
url += "motion";
Serial.print("Requesting URL: ");
Serial.println(url);
// This will send the request to the server
client.print(String("GET ") + url + " HTTP/1.1\r\n" +
"Host: " + HOST + "\r\n" +
"Connection: close\r\n\r\n");
delay(10);
// Read all the lines of the reply from server and print them to Serial
while(client.available()){
String line = client.readStringUntil('\r');
Serial.print(line);
}
Serial.println();
Serial.println("closing connection");
}
boolean connectWiFi(){
Serial.println("AT+CWMODE=1");
delay(2000);
String cmd="AT+CWJAP=\"";
cmd+=SSID;
cmd+="\",\"";
cmd+=PASS;
cmd+="\"";
Serial.println(cmd);
delay(5000);
if(Serial.find("OK")){
Serial.println("Connection");
return true;
}
else{
Serial.println("No Connection");
return false;
}
}
Why does a PIR sensor stay high with nodeMCU/ESP8266 board?
In essence, I never see the serial message "motion ended at.."
Months after but hopefully will help some others with the same problem. I was frustrated for weeks and tried several PIR modules with the same (frustrating) results, and what I found was that the problem was caused by the way I was flashing the firmware in the nodeMCU dev board.
I had the ESP-12E and was uploading the firmware using the following command:
esptool.py --port /dev/cu.SLAB_USBtoUART --baud 115200 write_flash -fm dio -fs 32m 0x00000 /Users/dev/nodemcu-firmware.bin
and the problem was the -fm dio (Dual Flash I/O mode) parameter. Some ESP8266 modules, including the ESP-12E modules on some (not all) NodeMCU boards, are dual I/O and the firmware will only boot when flashed with --flash_mode dio or -fm dio but in my case was the source of all my headaches. Once I flashed the firmware without that option everything started to work like a charm.