Help with RAMPS and dual endstops

I was cabling dual endstops to a ramps board using and while wiring what I thought it was the S with the - of the D15 and I had some smoke coming from my card. I have a spare one, and no complains since it is my responsibility know what I do.

What I think that happen is that I accidentally connected the - and + to the switch terminals closing them (not good) now the board seems to work getting the power from the USB, but not from the 12v input. I guess I have fried the shield :frowning:

The point is what can I do not to break again other card? the correct way is to connect the NC Normally Closed wired between s and - in the ends D3, D2, D14, D15, D18, D19?

Yea, you want them hooked to signal and -. I’m not exactly sure which pins you need, but I think you have the right idea. Also, if you’re handy with a soldering iron, pretty sure all you killed was the regulator on the arduino board. It’s pretty easy to tell, the hole that the magic smoke comes out of is usually on the top and fairly visible. Here’s a few I’ve killed as an example.


And Ryan sells the regulators if you have even minimal SMD soldering tools.

Hey Bill, I linked to the store! :wink:

Yeah, but you did it subtly, instead of IN YOUR FACE like I did. :slight_smile:

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Yes… it makes perfect sense to be just the regulator, since the card works fine while powered jus from USB (5V), the problem comes when I hook up to 12v

I’ve been playing along with the spare board, and found that using the end switches I used, it only seems to work when the three wires are connected, not just S and - as is stated in (tested with M119 command) I also tried with S and + and just the 3 wires seem to work. May be because of the board circuitry?

Those board have an LED on them that requires power to work. I would have expected them to use just mechanical switching for the NO and NC parts, but perhaps they do some sort of pull up / pull down with those little resistors and the capacitor, which would force you to provide power. Most people don’t get the fancy ones like yours, they just buy the switch itself.

Yes, I just used them since I had those laying around my basement from another project.

Anyway I’m very sure that the shorcut was I wrongly connected the cable since I have very few light. And I was close to did it again, but fortunately I decided to check this with my cellphone torch before powering the board.