Light intensity notification with EzloPi MeshBots

The EzloPi smart devices provide automation through simple, customizable use with our open-source EzloPi platform, making daily life easier and improving human-machine interactions.

Before moving into this example, it is very important to know about the device registration, provisioning and converting the ESP32 device into an EzloPi device along with knowledge of Web Flasher, MiOS Mobile Application for Android/iOS and the MiOS Web Application.

1. About this example

The goal of this project is to interface the LM393 LDR (Light Dependent Resistor) module with the EzloPi device to monitor changes in light intensity. Upon detecting a decrease in light, the system will use the EzloPi meshbot to send an email notification to the user. This project provides a convenient way to stay informed about variations in ambient light conditions which can provide insights about your smart home lighting conditions. Also users can monitor their smart home lighting intensity remotely by using the MiOS application.

2. Circuit Setup & Interfacing

The following components are required for interfacing with the EzloPi device:

  • ESP32 as an EzloPi smart device.
  • LM393 photo-resistive LDR module.

The wiring diagram is represented as follows:

The following connections are made in order to complete the circuit setup.

From ESP32 to LDR module:

  • Connect 3V3 from the ESP32 to the VCC of the module.
  • Connect GND from the ESP32 to the GND pin on the module.
  • Connect D5 from the ESP32 to the D0 Pin on the LDR module.

From ESP32 to the LED:

  • Connect the D5 pin from the ESP32 to the LED anode (long leg) through a current limiting resistor of 82 Ohms.
  • Connect the GND to the cathode (short leg) of the LED.

3. Interfacing the LDR sensor module using the EzloPi Web Flasher

1. Set up your device/hardware by visiting

  1. Log in using the credentials which you just set earlier while signing up.
  1. Now, click on the Connect Device button and a pop-up window will appear.
  1. Now, select COM Port to which your ESP32 device is connected. In our case, the COM3 port is used.

Click Connect.

  1. If you are new to this and it's your first time configuring, select Create new Device ID. Enter Wifi SSID and Wifi Password.
  2. In the Device Configuration, tab click on Digital Input.
  1. A window will open for inputting the following parameters:
  • Set a device name of your choosing. In our case, we set it to LDR.
  • Set OUT GPIO to 5.
  • Set the default value to LOW.
  • Then click Apply Button.
  • After clicking the apply button you can see a table of your setting in the device configuration tab.
  • Press the Flash Device button.
  1. A window will appear on the bottom right side of the screen displaying “Please press BOOT button while flashing begins.”
  1. Hold the BOOT button down until the next window appears on the bottom right side of the screen which says “Installation prepared. Please release the boot button now.”
  1. Release the BOOT button from your ESP32 when this pop-up on the bottom right window appears.
  1. After some time, a popup will appear saying Device Flashed Successfully! This means that your device has been set up successfully.

4. MiOS Web Application

  1. After configuring the controller with the EzloPi web flasher, head to
  1. Use the same credential to log in that you used for configuring the controller with the web flasher.
  1. Now, on the MiOS web dashboard, you will be able to see the tile for the touch sensor and the buzzer. The tile will indicate the status of the buzzer depending on the touch sensor being operated.


  1. On the right side of the screen under Automation, click on MeshBots.
  1. On meshbot screen, click on Create new MeshBot button present on the top right corner of the screen.
  2. After clicking on Create new MeshBot you will see this now under Automation MeshBot click on Cloud.
  1. On the next screen you will see that we can create a name of our choosing, in this case we write it as LDR.
  1. In the trigger tab you can set the TRIGGER for your device and in the ACTION tab you can set the action to be performed based on the trigger which you have created.
  1. Set these things in TRIGGER section:
  • Set Node Type to Device.
  • Set the Node to LDR.
  • Set the Capability to power.
  • Set the variables to status.
  • Set the Comparator to Equal(==).
  • Set the Value Type to value.
  • Set the value to false.
  1. Set these values in the ACTION section.
  • Set Controllable Type to Notification.
  • Set the User to Your user account but in our case the user account is Tayyab.
  • Set the Channels to email, push.
  • Set the Subject to Light intensity Update.
  • Set the Message body info to Light Intensity has been decreased.
  • After clicking the apply button you can see a table of your setting in the Current configuration tab.
  1. After clicking the save button you can see this screen on the top right corner of the screen.
  1. Here you can see your saved MeshBot. Now click on Dashboard.
  1. When the light incident on the LDR module is blocked, the LDR tile will turn blue and no notification is sent to the user.
  1. When the light is blocked again, the notification is sent to the user’s email.

5. MiOS App

You can download the MIOS Android app from the Google Play Store and Apple App Store.

Google PlayApple App Store

  1. After downloading the app, proceed to install the application and open it.
  1. Using the MIOS mobile application, create a new Ezlo Cloud account using the sign-up option. If you already have an account, you may proceed to log in.
  1. After successfully logging in, you will be able to see the number of controllers connected such as a lamp, fan, or any other device in the MiOS app. Tap on any controller of your desired ID:
  1. You will be able to see the status of your controller whether it is online or offline. Access the device dashboard, and tap the device. The following view of the dashboard will appear:
  1. Now, on the MiOS mobile dashboard, you will be able to see the tile for the touch sensor and the buzzer. Both will be functioning according to rules we have set in meshbot.
Buy Components

eZlopie Products A single-channel 5V relay module $00.00

eZlopie Products Momentary switch $00.00

eZlopie Products Level Shifter Module (BSS138) $00.00

eZlopie Products ESP32

eZlopie Products AC Lamp and Holder