This project creates a smart mailbox notifier that alerts you when mail is delivered. A PIR sensor detects motion inside the mailbox when the mail carrier opens the door or inserts mail. An ESP32 sends a notification to your phone via Wi-Fi using the Blynk platform.<\/p>\n
Difficulty:<\/strong> Intermediate A PIR sensor placed inside the mailbox detects motion when the door is opened or when mail is inserted. The ESP32 connects to your Wi-Fi and sends a notification to the Blynk app on your phone. You can also add an LED indicator to show notification status and a reset button to clear the alert after checking mail.<\/p>\n If your mailbox is far from Wi-Fi range or you need longer battery life, use ESP-NOW protocol to communicate between two ESP32 boards:<\/p>\n If your mailbox has a nearby power outlet, use a USB adapter and long cable. Ensure the cable is rated for outdoor use and protected from weather.<\/p>\n For battery operation, modify the code to use ESP32 deep sleep mode:<\/p>\n With deep sleep, battery life can extend to 6-12 months on 3xAA batteries.<\/p>\n This smart mailbox notifier eliminates the need to check the mailbox unnecessarily. With notifications sent directly to your phone, you’ll know exactly when mail arrives.<\/p>\n","protected":false},"excerpt":{"rendered":" Project Overview This project creates a smart mailbox notifier that alerts you when mail is delivered. A PIR sensor detects motion inside the mailbox when the mail carrier opens the door or inserts mail. An ESP32 sends a notification to your phone via Wi-Fi using the Blynk platform. Difficulty: Intermediate Estimated time: 2-3 hours Estimated […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9],"tags":[],"class_list":["post-3903","post","type-post","status-publish","format-standard","hentry","category-projects"],"blocksy_meta":[],"yoast_head":"\r\n
\nEstimated time:<\/strong> 2-3 hours
\nEstimated cost:<\/strong> $20-30<\/p>\nHow It Works<\/h2>\n
Materials Needed<\/h2>\n
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Circuit Diagram<\/h2>\n
Connection Table<\/h3>\n
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\n \nComponent<\/th>\n Pin<\/th>\n ESP32 Pin<\/th>\n<\/tr>\n<\/thead>\n \n PIR Sensor<\/td>\n VCC<\/td>\n 3.3V or VIN (5V)<\/td>\n<\/tr>\n \n PIR Sensor<\/td>\n GND<\/td>\n GND<\/td>\n<\/tr>\n \n PIR Sensor<\/td>\n OUT<\/td>\n GPIO 4<\/td>\n<\/tr>\n \n LED<\/td>\n Anode<\/td>\n GPIO 5 (through 220\u03a9 resistor)<\/td>\n<\/tr>\n \n LED<\/td>\n Cathode<\/td>\n GND<\/td>\n<\/tr>\n \n Push Button<\/td>\n One pin<\/td>\n GPIO 0 (with 10k pull-up)<\/td>\n<\/tr>\n \n Push Button<\/td>\n Other pin<\/td>\n GND<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n Blynk Setup<\/h2>\n
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Arduino Code<\/h2>\n
\/\/ Smart Mailbox Notifier with ESP32 and Blynk\n\/\/ Blynk IoT platform required\n\n#define BLYNK_TEMPLATE_ID \"YourTemplateID\"\n#define BLYNK_TEMPLATE_NAME \"Mailbox Notifier\"\n#define BLYNK_AUTH_TOKEN \"YourAuthToken\"\n\n#include <WiFi.h>\n#include <BlynkSimpleEsp32.h>\n\n\/\/ Wi-Fi credentials\nchar ssid[] = \"YourWiFiSSID\";\nchar pass[] = \"YourWiFiPassword\";\n\n\/\/ Pin definitions\nconst int pirPin = 4;\nconst int ledPin = 5;\nconst int resetButtonPin = 0;\n\n\/\/ Variables\nbool mailDelivered = false;\nunsigned long lastMotionTime = 0;\nconst unsigned long debounceDelay = 2000; \/\/ 2 seconds debounce\n\n\/\/ Blynk virtual pin for resetting from app\nBLYNK_WRITE(V0) {\n if (param.asInt() == 1) {\n resetAlert();\n }\n}\n\nvoid resetAlert() {\n mailDelivered = false;\n digitalWrite(ledPin, LOW);\n Serial.println(\"Alert reset\");\n Blynk.virtualWrite(V1, 0); \/\/ Update app status\n}\n\nvoid sendNotification() {\n if (!mailDelivered) {\n mailDelivered = true;\n digitalWrite(ledPin, HIGH);\n Serial.println(\"Mail delivered! Sending notification...\");\n \n \/\/ Send Blynk notification\n Blynk.logEvent(\"mail_delivered\", \"Mail has been delivered to your mailbox!\");\n \n \/\/ Update app status\n Blynk.virtualWrite(V1, 1); \/\/ 1 = mail waiting\n }\n}\n\nvoid setup() {\n Serial.begin(115200);\n \n \/\/ Initialize pins\n pinMode(pirPin, INPUT);\n pinMode(ledPin, OUTPUT);\n pinMode(resetButtonPin, INPUT_PULLUP);\n \n digitalWrite(ledPin, LOW);\n \n \/\/ Connect to Blynk\n Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);\n \n Serial.println(\"Smart Mailbox Notifier Ready\");\n Serial.println(\"Waiting 60 seconds for PIR warm-up...\");\n delay(60000);\n}\n\nvoid loop() {\n Blynk.run();\n \n \/\/ Check reset button\n if (digitalRead(resetButtonPin) == LOW) {\n delay(50); \/\/ Debounce\n if (digitalRead(resetButtonPin) == LOW) {\n resetAlert();\n while (digitalRead(resetButtonPin) == LOW) {\n delay(10);\n }\n }\n }\n \n \/\/ Check PIR sensor\n bool motionDetected = digitalRead(pirPin) == HIGH;\n \n if (motionDetected) {\n unsigned long now = millis();\n if (now - lastMotionTime > debounceDelay) {\n lastMotionTime = now;\n Serial.println(\"Motion detected in mailbox\");\n sendNotification();\n }\n }\n \n delay(100);\n}\n<\/code><\/pre>\nAlternative: Using ESP-NOW for Long Battery Life<\/h2>\n
\/\/ Sender code (mailbox unit) - ESP-NOW\n#include <esp_now.h>\n#include <WiFi.h>\n\nuint8_t receiverAddress[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}; \/\/ Replace with receiver MAC\n\nconst int pirPin = 4;\nbool lastState = false;\n\nvoid sendMotionAlert() {\n esp_now_send(receiverAddress, (uint8_t *)\"MOTION\", 6);\n Serial.println(\"Motion alert sent\");\n}\n\nvoid setup() {\n Serial.begin(115200);\n pinMode(pirPin, INPUT);\n \n WiFi.mode(WIFI_STA);\n if (esp_now_init() != ESP_OK) {\n Serial.println(\"ESP-NOW init failed\");\n return;\n }\n \n esp_now_register_send_cb([](uint8_t* mac, esp_now_send_status_t status) {\n Serial.print(\"Send status: \");\n Serial.println(status == ESP_NOW_SEND_SUCCESS ? \"Success\" : \"Fail\");\n });\n \n esp_now_peer_info_t peerInfo;\n memcpy(peerInfo.peer_addr, receiverAddress, 6);\n peerInfo.channel = 0;\n peerInfo.encrypt = false;\n esp_now_add_peer(&peerInfo);\n \n Serial.println(\"Sender ready\");\n delay(60000); \/\/ PIR warm-up\n}\n\nvoid loop() {\n bool motion = digitalRead(pirPin) == HIGH;\n if (motion && !lastState) {\n sendMotionAlert();\n }\n lastState = motion;\n delay(100);\n}\n<\/code><\/pre>\nInstallation Steps<\/h2>\n
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Power Options<\/h2>\n
Option 1: USB Power<\/h3>\n
Option 2: Battery Power with Deep Sleep<\/h3>\n
\/\/ Deep sleep code snippet\nesp_sleep_enable_ext0_wakeup(GPIO_NUM_4, 1); \/\/ Wake on PIR HIGH\nesp_deep_sleep_start();\n<\/code><\/pre>\nTroubleshooting<\/h2>\n
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Project Extensions<\/h2>\n
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Conclusion<\/h2>\n