I think many have heard about sensors for Arduino, they really can really help in your projects and homemade, and some projects without them are almost impossible. There are a lot of such sensors for arduino, there are even sensors for determining humidity and pressure, by the way, I did articles on similar modules earlier. An ultrasonic sensor is usually used to determine the distance to an object, it is really capable of measuring very accurately the distance to an object by the action of its radius, but it is not very small, and after all, many just need a sensor that can only determine if an object is nearby or not . It is about such a sensor that our today's speech will go.
This module is called TCRT5000, it is a small scarf with three cantacts on one side and with 2 separate elements on the other, these elements are an infrared LED and a module that is capable of receiving infrared radiation. This sensor works very simply, first the IR LED sends a small IN signal, it either reflects from the surface or not, if reflected, the photocell receives it, certain calculations take place in the microcontroller and it becomes clear whether there is an object nearby or not. There are many applications for this module, and I think many will support me in this.
The price of this product is 36 rubles, at the time of writing. Free shipping. Most reviews are positive.
Well, thank you all for your attention and good luck in future projects, friends!
Cost: ~ 36