mDot Device ID (Dev EUI) all Zeros After Downgrading firmware

The structure of the flash partition was changed to help safe guard the protected settings in the 4.0.0 mDot and xDot firmware.
When upgrading from older firmware (3.3.x and earlier) to 4.0.0 (and later), the flash will automatically be converted and protected settings preserved, but when downgrading from 4.0.0 (and later) to an older 3.x.x version of firmware, the protected settings will be lost and will need to be reconfigured.

Below are the steps to reconfigure the Protected Settings on the mDot and xDot:

1) Download the 3.3.5 firmware at the link below and flash firmware into mDot or xDot. Note that the file name will start with "mdot-" for mDots or "xdot-" for xDots, make sure to choose the appropriate firmware file.

Note: With the xDot, you will need to reset the xDot before the new firmware will run.

2) In a terminal at 115200 baud 8N1 connected to the AT command port, program the DevEUI (Node ID) from the label. Ignore the colon (":") between octets. For example:

3) Set the default frequency:
   AT+DFREQ= (where  is US915, AU915, EU868, ect. for example AT+DFREQ=EU868)

4) Store the changes to the protected-config.

5) At this point, SPI flash memory is restored and the application can be reloaded. The AT command firmware application is found at:

Note: Factory defaulting the settings on the Dot is highly recommend after any downgrade of the firmware.