Control buttons from old devices (like Coffee Machine)

Projects General Guidance
1

Hi, I want to control old devices, for example a Coffee Machine. I want to simulate a button press with the Arduino, instead of pressing the button physically.

My first thought was using relays, which would be okay, but they are big and loud, and a little bit overkill for simulating a Button, in my opinion.

Is there any better option?

2

Welcome

Try with a CD4066 or similar

3

Thank you very much, that is, what I was looking for!

4

google

 hijack buttons arduino

and poke around. There are a few ways to go. If you have single pushbuttons, the 4066 or a transistor woukd do. If you looking at a matrix keyboard, it might be easier to spoof the connection between a row and column using CMOS multiplexers.

a7

5

Thank you, too!

6

Be careful, I recently saw a coffee machine controller without galvanic separation from mains here on the forum....

7

Sorry, I did not read carefully. If this is a "dumb" coffee machine with only one button to switch the heating element, you cannot use a CD4066 for that, you will need to use a relay, maybe a solid state relay if you don't want the click..

8

No, that was just an example. I had a fully automatic coffee machine in mind, or an amplifier for a soundsystem. I want to connect an ESP to these kind of devices and control them via home assistant :wink:

9

Well my Mr. Coffee has buttons that can be hijacked.

The first step in any hack like this is to determine the switch requirements as to voltage and current to be controlled.

As noted, a switch that just throws mains to the heating coil will have to become a relay, solid state or not.

Most battery operated devices have switches that can def be hacked easily.

a7

10

I was referring to a system that had its low voltage system directly connected to mains.
Plug into socket: not recommended, but board at level of Neutral pole (close to 0V).
Plug into socket other way around (in EU that is possible, with some plug/socket systems in other countries it is not) : board at phase voltage (here 220V AC (pretty dangerous)).

It works like this LED mains tester...

P--------||------------+------+
                       |      |
                       -      v  
                       ^      - \\
                       |      |
N----[ 220 ]-----------+------+
11

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.