Best posts made by veng1

Why not use a large value resistor, say 1M, between V- and mains ground?

That will still bleed off a static charge but not, hopefully, impact ground loops as much.

@dc42 I understand that. The macro early in this thread that takes 10 measurements at the point X151 Y161 works fine in the /sys folder. However, if it is edited to remove the X and Y co-ordinates like:

M291 P"Probe will be tested 10 times and return mean and standard deviation. Ok or Cancel?" R"WARNING" S3 ; User must click OK or cancel.
G28
G30 P0 Z-9999
G30 P1 Z-9999
G30 P2 Z-9999
G30 P3 Z-9999
G30 P4 Z-9999
G30 P5 Z-9999
G30 P6 Z-9999
G30 P7 Z-9999
G30 P8 Z-9999
G30 P9 Z-9999 S-1

it does not stay at the current position but moves in X. I believe it should just take 10 points at the current location without moving.

@Catalin_RO

I also have said professional measuring tools and assumed you did also based on some of our earlier conversations but I was describing a test approach that anyone could implement to check squareness.

@poofjunior I've ordered parts to prototype such a board. I don't know yet if it can be built at the same size as the 2209 board more or less as it would be nice if it could dissipate more current.

I'm targeting 48V.

No idea of cost yet.