You can use between 1000-1500 ohm resistor.We always recommend a 1K.

 

1.3-2.2k from what Iīve seen referenced. Any particular reason? Itīs not drawing much, so the heat difference canīt be much for the extra half k. Not much current left being that far reduced, perhaps thatīs the reason for the recommendation(5v = i x 1500)?

Couple have stated elsewhere with the usual 1.5 didnīt have it drop it enough. Of course online, having to take that with massive amounts of salt..