🎯 Goal

Goal: Simulate a system that prevents someone his is too close to some place or device by turning on a LED.

At a later stage, user will be able to turn on/off the system remotely via a web server.

use case can be used to prevent your child of dangerous place or device, like a hotplate ?

Steps

I divide the system into 3 separate system

• LED sys
• Presence/Distance sensor
• Web server

Use tinkercad to simulate the project. Please try it, you will love it.
https://www.tinkercad.com/

LED device

diagram (tinkercad)

Distance sensor

Diagram

Web server + Wifi CARD

Testing server.

Final stage

In order to connect/plug PINS of the wifi card i used this diagram below.

LED + Distance sensor + Wifi card

I set up a range distance of 40cm to active the LED.

Test

Logs show that the server can get the distance from our system.

Issues

• Instead of set up the wifi card you need to install the correct driver, this is tricky, for me this one was a solution: CP210x USB to UART Bridge VCP Drivers
  Link : https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers

• Sometimes, a wifi card PIN must be activated to switch to OUTPUT mode.

• I order to read and write data from arduino card at the sametime i need an asynchronous code.

Libs

Distance sensor HCSR04
https://github.com/jeremylindsayni/Bifrost.Arduino.Sensors.HCSR04

Wifi card
https://fr.macerobotics.com/developpeur/tutoriels/esp8266-controle-dune-led-par-wifi/