endstop maximum current
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What's the maximum current available on the endstops on the Duet or Duex5?
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The endstop switches each need to be able to sink 1.5mA current for the Duet 2 WiFi and Duet 2 Ethernet, and 2.1mA for the Duet 06 or 085. This is not usually a problem, except with some optical endstop switches that were not designed properly for 3.3V operation.
https://duet3d.dozuki.com/Wiki/Connecting_endstop_switches
Does that help?
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@phaedrux
thanks so much friend.
I looked there and also on the forum for the answer to my question which I will clarify.I'm trying to determine the maximum current the end stop circuit can pass so as to eliminate certain end stop switches with LED loads tied directly inline with the signal path.
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Connecting that switch between input and ground won't work because the voltage drop of the LED will be too high.
You could connect that switch to a Duet 3 IO port between +5V and IN, and connect a pulldown resistor of about 470 ohms between IN and ground. That might work for the Duet 2 as well, but the noise margin would be reduced because of the need to sink 1.5mA for the endstop LED on the Duet.
