Keyless Mailbox Based on Internet of Things

Abstract

This paper proposed a keyless mailbox based on the Internet of Things by notifying via the Line and Blynk application when someone sends a letter to a mailbox. We applied an infrared sensor with the microcontroller ESP32 to detect envelopes and notify recipients via Line and Blynk Applications. To open the mailbox, the users must scan their fingerprints via a fingerprint scanner to verify the permissions before opening the mailbox. In addition, the solar panel is installed for voltage source and charging a battery during usage in the daytime. As a result, twenty-five envelope detections were tested by notifying via Line and Blynk applications, respectively. It was found that the average delay time of reporting was 2.8 seconds and 2.9 seconds, respectively. Then, twenty-five fingerprint scanning was tested for opening the mailbox by notifying via Line and Blynk applications. The average delay time for reporting was 2.7 seconds and 2.8 seconds, respectively. In the experimental test, we used a solar panel to connect with a battery between 6:00 a.m. and 6:00 a.m. the next day. It can also work by charging the voltage into a battery for approximately 10 hours, the maximum voltage is 11.82 V, but the battery is supported the usage time of 2 hours after the solar panel has no sunlight. This voltage drop was because the keyless mailbox always used the circuit’s voltage supply, which wasn’t considered an energy-saving mode. The life of the battery is low.