time instead of iteration for turning off light

hmmd-sensor-waveshare.ino

@@ -6,7 +6,8 @@
 // Normal mode command
 #define COMMAND "FDFCFBFA0800120000006400000004030201"
 #define PRESENCE_DISTANCE 100
-#define COUNT_STATUS_DIFFERENCE 5
+#define DELAY_STATUS_CHECK 1000 // delay (in ms) between two checks of the presence
+#define POWER_DELAY 20000 // delay (in ms) until turning off the screen
 
 // Zigbee
 #define OCCUPANCY_SENSOR_ENDPOINT_NUMBER 1
@@ -14,7 +15,7 @@
 ZigbeeOccupancySensor zbOccupancySensor = ZigbeeOccupancySensor(OCCUPANCY_SENSOR_ENDPOINT_NUMBER);
 
 bool isPresent = false;
-int countDifferent = 0;
+unsigned long lastMotionDetected = 0; // time when the last motion was detected
  
 void setup() {
   initSerial();
@@ -25,7 +26,7 @@ void setup() {
  
 void loop() {
   readAndProcessSensorLines();
-  delay(500);
+  delay(DELAY_STATUS_CHECK);
 }
 
 void initSerial() {
@@ -95,25 +96,24 @@ void readAndProcessSensorLines() {
  
     // Check if the line contains the "Range" information
     if (line.startsWith("Range ")) {
+
       // Extract the substring after "Range "
       String distanceStr = line.substring(6);
       int distance = distanceStr.toInt();
       bool currentStatus = distance <= PRESENCE_DISTANCE;
 
-      if (currentStatus != isPresent) {
-        countDifferent++;
-      } else {
-        countDifferent = 0;
+      if (currentStatus == 1) {
+        lastMotionDetected = millis();
       }
 
-      // change the status, if the last n updates were different than the current status
-      if (countDifferent >= COUNT_STATUS_DIFFERENCE) {
-        isPresent = !isPresent;
+      if (currentStatus && !isPresent) {
+        isPresent = true;
         bool res = sendZigbeeOnOffCommand(isPresent);
-        Serial.print("Message sent: ");
-        Serial.print(isPresent);
-        Serial.print(" - successful: ");
-        Serial.println(res);
+        Serial.println("Motion detected, turning screen light on");
+      } else if (!currentStatus && isPresent && (millis() - lastMotionDetected >= POWER_DELAY)) {
+        isPresent = false;
+        bool res = sendZigbeeOnOffCommand(isPresent);
+        Serial.printf("No motion detected for %d ms, turning light off.\n", POWER_DELAY);
       }
     }
   }