Advice needed on a much needed upgrade

[FourRings]

@PaulRB

I suspect there would be no problem getting the wemos to operate those relays. The wemos pin only has to source/sink enough current to illuminate the IR led inside the opto-isolators. With this type of board, it's often the case that a LOW output from the Arduino/esp energises the relay and a HIGH switches it off.

The question remains: how much current do the relay coils draw? The link you gave says nothing about that.

Yeah, I don't know about the current rating, sadly. I imagine all the boards that use the blue Songle relays draw about the same. I'll test them with the ammeter when they arrive.

Outside of the IN trigger, I guess the only thing to suss out is how to connect the power to the relay board itself and whether or not to keep the JD-VCC pin on or off.