Having a great time using the TNG software with the mk3drv board. Everything working great and milling my PCBs ended up a lot easier than I thought possible.

Now I want to do a little convenience update on my machine: I want to use Output1 to activate a +5V Relay to turn on and off the spindle. Found and configured everything on the software side.

Now my big question: what kind of signal is on O1? Is it +5V? TTL?

I doubt I can just hook up a relay to it. But can I use the little circuit in Fig. B of this link?

Controlling Relays with Logic signals.

A little heads up would be appreciated and I rather ask than fry my nice board.