Nano Loco upgrade from develop-172-69937359

I have found that it is best to "walk" them up a few steps - at least to the next production release, (after dev-172) and then on to the latest production or nightly.  Especially when coming from pre- 3.16 versions. 3.16.2 I believe is a good stepping stone from the early stuff. 

And just to be clear, be sure to match the board revision level XM->XM or XW->XW when loading AREDN Firmware.  Don't mix them or you will brick the unit.
One good way to tell XM models usually have less than 15M of /temp and 6M of /m   XW usually have 30M+ /t and /m (with the exception of Rocket Models, which have about the same memory in their XM and XW models upwards of 30-33t and around 34-36M)