How to control an electrical circuit from a PC?

Question

System administration

Hello.
I received a task not according to my profile.
There is a control panel with 12-15 buttons that are connected to a board powered by a conventional PC power supply.
All buttons share a common ground wire.
The task is to manage these closures from a PC, using the keyboard\mouse\web interface\possibly remotely.
Given that I'm doing a little different things, I can't even imagine how to google it. I need your help

Answer 1

The frontal solution is to use the old 8-bit LPT port, which is even on many modern computers (in a hidden state, in the form of a comb on the motherboard), and each of the bits of which is easily controlled by software, writing zeros and ones to the corresponding port registers. The logical signals issued by the port bits must be applied to the bases / gates of transistor switches, the collectors / drains of which are connected in parallel with your buttons. This diagram shows two options for such control - tied to the total mass and decoupled through an optocoupler:
This method makes it easy to control 8 loads from a computer. If you need more of them, you have to come up with multiplexing. The easiest option is to reduce the number of output channels of the port to 7, increase the number of keys to 14 (as you need), and use the eighth bit of the port to switch two groups of 7 keys: at zero - from 1 to 7, at one - from 8 14. But such a simple solution will not allow using the keys of the first and second groups at the same time. To make it possible to simultaneously control so many keys, the control signals will have to be stored in trigger registers, and this is already more difficult.

Answer 2

ESP8266 + for example tlp504a
But this is only if the buttons are not power. There's another solution

Answer 3

You need to add tags to the question: Electronics, Microcontrollers, ... and arduino.
1. for information: Management of the microcontroller via the Internet?
2. Somewhere I wrote here, but I didn’t find something. There are analog boards in a computer to control analog signals, and then you put a transistor on (you need electronics)