Button Hacking

Projects General Guidance
1

I have been googling and looking at tutorials but am just starting and am having trouble finding simple information. Thank you for your help.

If i connect wires directly to a circuit board to replace a button (like a mode selection on a fan remote) can these wires be attached to pins on the Arduino uno to activate the button?

Could I do this with just a ESP8266 wifi unit or does it need the arduino uno also?

How would i extend it to control 20 or more buttons?

Do I only need a relay if I am activating something by interrupting the power supply?

2

Ok start off with your words. You do not control buttons, buttons are an input to an Arduino.
If you want an Arduino to override a button on an other device you need to know a lot about the other device. The Arduino can only supply a signal of either 0V or 5V at a current not much more than 20mA. So if your device will respond to that then fine connect it directly, but most devices will need more than that.

Therefore you normally need some sort of driver circuit between the Arduino and the thing you are trying to control. Even a relay will need something to boost the Arduino’s signal enough to drive it from a pin.

If you use an ESP8256 then this is only 3V3 not 5V and a lot less current. But with the right design you can use it without a Uno.

But you must know, or measure what your device needs.

More outputs can be obtained by using shift register chips or port expander chips.

3

Thank you Mike that is great info and puts things into perspective, i think i will need a lot of learning :slight_smile:

4

It sounds to me like what you may want to do is control the fan, and other devices with infra-red (IR) remote controls, via the internet, or at least over a network.

If so, you can connect IR receiver components that enable an Arduino to learn the codes for each device. Then you can use IR LEDs to send those codes under control of a web page or app. There are IR libraries that can learn and send IR codes using Uno/Nano etc, so I expect there will be versions of those adapted or esp.

Controlling devices this way should be a lot simpler overall then hacking IR remote controls, and does not risk damaging/destroying the remotes.