Well this appears to be a cable length issue. Somewhere between 100mm 5m and 9m of cable this appears to stop working reliably. At 5m of cable this does reach through all of the drag chains on a 4ft x 4ft table and work ok. That’s what I get for testing with the rest of the length of cable I was using not cut down yet.
It looks like the grblHAL code has some ability to change the brightness of the LEDs; would it be possible to expose this to gcode or a firmware setting? These 5050 packages are obnoxiously bright without some sort of diffuser.
