Old PSTN entry phone - door opening - #4

In this article I'm  describing the final version of hardware and firmware for the door opening.

Previous articles :

• https://hanixdiy.blogspot.com/2020/05/old-pstn-entry-phone-door-opening-1.html
• https://hanixdiy.blogspot.com/2020/05/old-pstn-entry-phone-door-opening-2.html
• https://hanixdiy.blogspot.com/2020/05/old-pstn-entry-phone-door-opening-3.html

Old PSTN entry phone - door opening - #3

In this article I will discuss  about how to design a circuit capable to "read" the rotary dial and relative code.

Old PSTN entry phone - door opening - #2

 In the previous article I discussed about some theory of operations and how to deal with the hardware.
In this article will start to discuss more in details about the hardware we want to design based on a real example.

Old PSTN entry phone - door opening - #1

This can be an interesting project.
The idea is to use an old PSTN phone to control the user end of an entry phone system.

Different functionalities can be developed, this article is concentrated to the door opening one.

The idea is to interface the rotary dial of an old PSTN phone with a small MCU capable to decode a number composed with the rotary dial and activate a relay if a specific number is selected.

A family size UV sterilizer - intro

In this time of COVID is necessary to sterilize often things, like masks and objects.

To do so I decided to build an UV-C Box Sterilizer.
UV lights are used to sterilize object since ... forever :). On the market exists UV sterilizer for phones and small objects but this is the point, is not easy to fit in it many objects.

Thus the idea to build a bigger box capable to easily sterilize everyday objects, including facial masks and small PPE.
I will update this article every time I will add more information/details about the construction/test.