This project creates a self-powered PIR motion sensor that runs entirely on solar energy. It is ideal for remote locations where running power cables or changing batteries is impractical. The system stores energy in a supercapacitor or rechargeable battery, providing operation through the night.<\/p>\n
Difficulty:<\/strong> Advanced A small solar panel charges a supercapacitor or lithium battery during the day. An ultra-low power PIR sensor (Excelitas PYD 2597 or Panasonic EKMB) draws only 2-6 \u00b5A, allowing continuous operation. When motion is detected, the system wakes a microcontroller to process the event and optionally transmit via low-power radio (LoRa, Zigbee, or Bluetooth).<\/p>\n VCC<\/th>\n 3.3V<\/th>\n GND<\/th>\n GND<\/th>\n OUT<\/th>\n GPIO (with 10k pull-up to 3.3V)<\/th>\n WUP<\/th>\n GPIO (interrupt pin)<\/th>\n<\/tbody>\n \u8868<\/p>\n Component power consumption:<\/strong><\/p>\n With 10 events\/day: 0.216 mAh + 0.021 mAh = 0.237 mAh\/day<\/p>\n With 1000 mAh battery: 1000 \/ 0.237 \u2248 4,200 days \u2248 11.5 years (battery self-discharge limits to 2-3 years)<\/p>\n This energy-harvesting PIR sensor provides maintenance-free operation in remote locations. With proper design, it can operate indefinitely without battery changes.<\/p>\n","protected":false},"excerpt":{"rendered":" Project Overview This project creates a self-powered PIR motion sensor that runs entirely on solar energy. It is ideal for remote locations where running power cables or changing batteries is impractical. The system stores energy in a supercapacitor or rechargeable battery, providing operation through the night. Difficulty: Advanced Estimated time: 4-6 hours Estimated cost: $40-60 […]<\/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-4045","post","type-post","status-publish","format-standard","hentry","category-projects"],"blocksy_meta":[],"yoast_head":"\r\n
\nEstimated time:<\/strong> 4-6 hours
\nEstimated cost:<\/strong> $40-60<\/p>\nHow It Works<\/h2>\n
Materials Needed<\/h2>\n
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Circuit Diagram<\/h2>\n
Power Management Section<\/h3>\n
\nSolar Panel (+) --- Schottky Diode ---+--- TP4056 IN (if using battery)\n |\n +--- Supercapacitor (+) (if using cap)\n |\n +--- LDO (MCP1700) IN\n |\nSupercapacitor\/Battery (-) ------------+--- LDO GND\n |\nLDO OUT (3.3V) ------------------------+--- PIR VCC\n +--- MCU VCC\n<\/pre>\n
Sensor Connection<\/h3>\n
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Component<\/th>\n Pin<\/th>\n MCU Pin<\/th>\n<\/thead>\n \nPIR Sensor (PYD 2597)<\/th>\n PIR Sensor<\/th>\n PIR Sensor<\/th>\n PIR Sensor<\/th>\n Arduino Code (ESP32-C3 with Deep Sleep)<\/h2>\n
\/\/ Energy Harvesting PIR Sensor\n#include <esp_sleep.h>\n\nconst int pirPin = 4;\nconst int wakePin = 5;\nconst int ledPin = 8;\nconst int batteryPin = 3;\n\nRTC_DATA_ATTR int eventCount = 0;\nRTC_DATA_ATTR unsigned long lastWakeTime = 0;\n\nvoid setup() {\n Serial.begin(115200);\n \n pinMode(pirPin, INPUT);\n pinMode(ledPin, OUTPUT);\n \n esp_sleep_wakeup_cause_t wakeup_reason = esp_sleep_get_wakeup_cause();\n \n if (wakeup_reason == ESP_SLEEP_WAKEUP_EXT0) {\n digitalWrite(ledPin, HIGH);\n delay(500);\n digitalWrite(ledPin, LOW);\n eventCount++;\n sendNotification();\n lastWakeTime = millis();\n } else if (wakeup_reason == ESP_SLEEP_WAKEUP_TIMER) {\n reportBattery();\n }\n \n goToSleep();\n}\n\nvoid sendNotification() {\n Serial.print(\"Motion detected! Total events: \");\n Serial.println(eventCount);\n delay(100);\n}\n\nvoid reportBattery() {\n int raw = analogRead(batteryPin);\n float voltage = (raw \/ 4095.0) * 3.3 * 1.5;\n Serial.print(\"Battery voltage: \");\n Serial.println(voltage);\n}\n\nvoid goToSleep() {\n esp_sleep_enable_ext0_wakeup((gpio_num_t)pirPin, 1);\n esp_sleep_enable_timer_wakeup(24 * 60 * 60 * 1000000ULL);\n esp_deep_sleep_start();\n}\n\nvoid loop() {}\n<\/code><\/pre>\nPower Budget Calculation<\/h2>\n
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Installation Steps<\/h2>\n
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Project Extensions<\/h2>\n
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Conclusion<\/h2>\n