Set to emit greetings when recognizing faces on Dahua decive

Face detection is a fairly common function in today’s surveillance camera system. There are many practical applications, you can imagine, when a customer enters the store, the Camera will automatically emit the message: “Hello, customer”. Follow this article to implement this function together.

1. Working principle

To implement this idea, I will use the Alarm-out port behind the recorder. When there is an event signal face recognition will close the circuit -> power supply to the automatic audio circuit.

Wiring diagram is as follows:

2. Instructions for setting up face recognition configuration

Do it step by step as follows:

3. Function demo video

The following is a demo video of the function that emits greetings when face recognition is successful, I have already set it up. However, there are limitations:

  • The delay is quite high, about 2 -> 3 seconds, cause the circuit needs to start and open the file from the memory card
  • For this self-generating circuit Audio will prioritize reading from MicroSD, if you use USB, it may delay a bit more.
  • The circuit is integrated with Alarm-out at the recorder, so it is necessary to wire the signal from the recorder to the speaker to output the sound.

To deal with the high delay, you can contact the shops to redesign the higher quality music autoplay circuit. I tested it on a fake circuit of 35,000 VND 🙁

4. Scalability

Because this method is used through the Alarm-out port, so you can use it with many different customizations:

  • Can be combined with any recorder, camera (requires Alarm-out).
  • Customize broadcast content: siren, barking, alarm sound theft, guest alert, …
  • Can be combined with many different events such as: Motion detection, SMD, IVS, Face detection, people counting, …

The above is what I know about this solution, hope it can help you. Thank you for following the article!!!