Hi there, I am modernising my old Prusa, which involves a newly-soldered sanguinololu board. I used to have Gen 3 electronics and I want to re-use the old opto endstops (v2.1). When no endstops are attached to the electronics board, I read 5V between GND and V+ (or SIG if I switch it in the firmware). But when I plug in the endstop, I read ~1.8V at SIG and ~0.9V at V+. The LED does not light up on the endstop board and nothing happens when I trigger the opto switch. These endstops worked just fine with the old electronics, so why not with the Sanguinololu? Thanks. https://reprap.org/forum/read.php?158,377809,377809#msg-377809 Sun, 12 Jul 2026 08:30:14 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?158,377809,378334#msg-378334 https://reprap.org/forum/read.php?158,377809,378334#msg-378334
I am a bit embarrased since I missed this info on the wiki page.

And Traumflug, yes, I had already switched two wires on my cables, as the pinout is a bit different, but thank you for the heads-up ;)

Now to make all the rest work...]]> Eriksen Sanguino(lolu) Sat, 05 Jul 2014 03:31:01 -0400 https://reprap.org/forum/read.php?158,377809,377973#msg-377973 https://reprap.org/forum/read.php?158,377809,377973#msg-377973 Traumflug Sanguino(lolu) Fri, 04 Jul 2014 06:39:29 -0400 https://reprap.org/forum/read.php?158,377809,377894#msg-377894 https://reprap.org/forum/read.php?158,377809,377894#msg-377894
Take a look at the bottom of your board eg Bottom of PCB

Between the exp pins on the left and the and the endstops pins on the right is voltage selector pads, put a solder blob from the middle pad to the +5 pad. (make sure not to cross all 3 pads)]]> Dust Sanguino(lolu) Fri, 04 Jul 2014 03:03:14 -0400 https://reprap.org/forum/read.php?158,377809,377809#msg-377809 https://reprap.org/forum/read.php?158,377809,377809#msg-377809
I am modernising my old Prusa, which involves a newly-soldered sanguinololu board. I used to have Gen 3 electronics and I want to re-use the old opto endstops (v2.1).

When no endstops are attached to the electronics board, I read 5V between GND and V+ (or SIG if I switch it in the firmware). But when I plug in the endstop, I read ~1.8V at SIG and ~0.9V at V+. The LED does not light up on the endstop board and nothing happens when I trigger the opto switch. These endstops worked just fine with the old electronics, so why not with the Sanguinololu?

Thanks.]]> Eriksen Sanguino(lolu) Thu, 03 Jul 2014 17:40:52 -0400