Hi, seems original code disappeared with my previous laptop, but I had some junk code laying around and could re-create it. I attach the measurements here, about 3.07 mA in sleep mode. The trick seems to be to put the SAMD21 to sleep properly. If you open a case in our case system I’ll give you the (very ugly) code as well.MKR1400 - 3mA.otii (1.2 MB)