Hooking a big red button up to an rpi

Seemed like a simple enough beginner project, I want to have a comically large button that is hooked up to an rpi, that when pressed writes something in a discord channel. I’ve never messed about with electronics to any great degree before, and used the following link:

https://www.circuito.io/app?components=9443,200000,305155

as a guide to what I needed to buy, which included:

Item Sku Qty
Big Dome Push Button - Red COM-09181 1
Solderless Breadboard - 300 Tie Points (ZY-60) CE05102 1
Raspberry Pi 3 Model B+ CE05436 1
Resistor 10K Ohm 1/4 Watt PTH - 20 pack (Thick Leads) PRT-14491 1
Premium Jumper Wire 10-Pack M-F 6" Black POLOLU-1720 1
Pimoroni Pibow 3 Coupé (Raspberry Pi 3, 2, & B+) CE00319 1

I excitedly opened the box today only to immediately realise that I have no idea what I’m doing.

My main point of confusion atm is hooking up wires to the buttons microcontroller. the microswitch looks like it lends itself to being soldered rather than being connected to the jumper wires I bought. Is there a better way to hook that up to the breadboard as shown or am I going to have to make another order?

Any assistance would be appreciated, heckling is encouraged.

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The Big dome Button uses spade connectors (links below) for the switch and the light. The size is not stated. The biggest expense would be the crimp tool (link below), and if your only using it once; over the top cost. You can solder wires, but I would use crimps as I like to make my stuff reusable or changeable in the future.

BUT … you could use this to connect it. Alligator clips to the switch and female pins to Pi.
Easy but not robust.

OR … these if you want to use the breadboard.

Regards
Jim

The light is 12V, web page says LED, but it may just be an incandescent light globe. Hard to tell from the web page. Depending on the current the light draws you may need a driver device. The Pi cannot output more than a few milliamps on GPIO pins.

The switch would be ok connected to GPIO pins as shown in the link you provided.

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Thanks Jim for the information! with the alligator clips to female pins you mentioned, Would I be better off getting https://core-electronics.com.au/small-alligator-clip-to-male-jumper-wire-bundle-12-pieces.html so that I can pin them into the breadboard as shown on the diagram?

Also I have cracked open the lamp, and found that there is in fact an LED in there, that is also removable. Assuming that the led doesn’t complete the circuit, can I just remove it so that I don’t have to worry about the pi powering it? the light seems pretty tiny.

Also, going back to the part where I’m in the dark about this whole thing, what is the purpose of the resistor on the breadboard?

Here is the light being removed from a video I found, same product to my understanding:

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Hi Dominic, Welcome to the forum :slight_smile:

That is a pull-down resistor, it’s there so that when the switch is open and the digital input isn’t connected to anything the logic will be lightly pulled down to ground instead of floating around to a random unpredictable state and doing funny things to your circuit.
I’ll link an indepth tutorial below if you are interested in the gory details.

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Thank you Trent! I’ve been here a half hour and am already super impressed with the quality of the content and the people on this forum.

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Hi Dominic,

Cheers, it’s members of the community helping each other that make it work so well. @James46717 put together a spot-on response quicker than I could get to it.
I’m off for the weekend now but that certainly doesn’t mean the community activity on the forum slows down at all!

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Yes. Male ones for the breadboard.

See attached pic below from the Core Electronics web page, I added the text and arrows.
I assume the pins shown are used to power the LED and if you don’t connect them to anything it wont matter. Removal of the LED would be fine.
I have used similar buttons and that is how they are wired. Micro switch separate from the LED.

Trent has covered the purpose of the resistor. If it was not there the switch would connect 3.3V to GND shorting out the supply and stopping the Pi from working; NOT good. Essentially the GPIO pin of the Pi is at GND when the button is not pressed and at 3.3V when the button is pressed, very easy for the Pi to see and do something.

cheers
Jim

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You’re a legend Jim, I’m gonna go pick up some alligator to male pins and give it a shot. Really appreciate you taking the time to lay out your answers the way you did!

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How did you go, Dominic? Any progress so far?

I love the idea of having a ‘Big Red Button’ for some arbitrary task! From my robocup days I do remember always wanting the run switch on our robots to be like a big missile launch switch for comedic value, something like a toggle switch with this cover:

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