Toggle buttons with timer

Hello.

I dont know if I am about to embarc on the arduino-trip or not so I place my question to the allmighty community!

I have 3 pushbuttons thats should operate 3 relays. Every push of a button should activate or deactivate its dedicated relay. But I also want a timer to start when the relay is activated, after ~60 seconds the relay should be deactivated

Is this doable with arduino and can you guys hint me in the right direction about hardware and program examples?.

I got a UNO r3 from a friend, is that enought or do I need some other hardware? (relays, buttons, etc of course!!)

You need relays :D In general you can not directly control relays from the Arduino but you need some form of driver. You can buy readily assembled boards (e.g. with 4 relays that have everything that is needed) that you can basically straight away hook up. Just pay attention to power supply.

From a software perspective, it should be reasonably easy.

Check if button pressed if so, if relay is on, switch off else switch relay on and 'record' current time

Check time if 60 seconds passed, switch relay off.

Repeat for the other relays.

Thanks… I will then dig into this world (Stolle 0 experience of arduino)
I thought that I would be able to feed the relay-coil directly from an output on the uno r3

You can run tiny "reed" relays directly from pins IF the coil current is less than 20mA but you still need a kickback diode across the coil and be very careful with diode polarity.

For a smallish relay, see the attached image for a cheap basic driver.
Transistor is pn2222 or equiv, and resistor is about 1000 ohms.
–Michael

Bipolar.png