Limit Switch Wiring?

[oldrayj]

I’ve been trying to piece together the info I’ve found on the forum in order to properly wire limit switches. Is the diagram below correct? If not, please point me in the right direction. Thanks.

Limit1.png (159.14 KiB) Viewed 11864 times

[PsyKo]

I don't think this is correct, but I'm no expert in electronic.

I think you simply have to remove the Red +5V wire since the limit pins are already held HIGH. When the switch is closed, they are connected to GND which trigger the limit detection.

Below is what I would do, assuming the left and right pin of the switch connects when the switch is closed :

vhbbewj6.jpg (33.02 KiB) Viewed 11859 times

If someone could confirm.

[cvoinescu]

That's not good either. You want the pull-ups, as the internal ones are weak. You want 1K or slightly less.

I can't scan or draw anything right now, so I'll try to use words. You have six switches and three resistors. The resistors are connected between +5V and the three input pins on the Arduino. The X switches are connected, in parallel, between one of the pins and ground. Same for the two Y switches on a second pin, and the two Z switches on a third pin. The switches should be NO, so when they're not pressed the resistors pull the pins up to +5V, and when any one is pressed, the respective pin tied to GND.

The original diagram is almost right, except half of the resistors aren't necessary, +5V and GND are swapped, and you should use the C and NO terminals of the switches, not C and NC.

Hope this helps.

[oldrayj]

Thanks for the input. Really helped. I'm going to make a new diagram to make sure I get it right. Thanks again.

[oldrayj]

Another try.

Limit1 (2).png (165.98 KiB) Viewed 11822 times

[cvoinescu]

Swap the 5V and GND connections to the Arduino (so that the resistors go to 5V and the wire common to all six switches goes to GND) and you have it. Also, 3K3 is probably fine, but I'd use 680 ohm to increase noise immunity (especially if you run these wires along the stepper cables).

[oldrayj]

Third time's a charm (hopefully). Thanks for your patience.

Limit3.png (143.22 KiB) Viewed 11797 times

[cvoinescu]

Yay! Perfect.

[Tom Smith]

I'm a big fan of this kind of instructions - my electronics skills are sketchy at best, and a clear picture is worth, well, a thousand words

Thanks oldray, cvoinescu (sometimes I wish I knew peoples names, addressing people by their forum tags seem odd sometimes

Tom

[cvoinescu]

Hi, Tom. It's Catalin, or Cat for short.