IoT Automation - Office Air Conditioner (AC) using sound sensor

Using IoT automation to automatically control the Air Conditioner using sound sensor for less often used areas.

Posted by Vivek on 24 Apr 2019


We have a corner place in office which we use as casual area. The area has a dedicated AC. We don't often spend time in the area (mostly used to play competitive carrom matches).

It happens quite often that we switch on the AC and then we forget to switch it off even when no one is in the area.

We needed an automated option where the AC would switch on automatically when we are playing carrom and will switch off when we leave.


We used IoT to solve our problem using these items -

  • NodeMCU ESP8266
  • Sound sensor
  • IR LED
  • Some wires
  • Breadboard
  • Arduino programming (C++)

Sound Sensor Automation

We used our programming talents to build a simple circuit to get input from sound sensor and if a sound is detected at regular intervals, it would signal the IR Led to switch on the AC at a particular temperature.

Once the sound is no longer detected for an interval of 2 minutes, it would signal IR led to switch off the AC.

The solution fully automates the control of AC and saves costs on electricty. It is specially useful in meeting rooms to control light and AC.

We will be adding a temperature sensor in the same circuit to enable us to control the temperature of the AC.

Next steps

We are working on more automations in our new office. If you are looking to automate your office space / home, please connect with us - Contact us.

- Vivek

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