u-blox XPLR-AOA-3, User Manual

Page: 28 / 44

UBX-22006906 - R03 Page 28 of 44
C1-Public
5.3.3 Restore Eddystone Instance ID
All u-blox modules are delivered with a u-blox MAC address, which is written into the UICR register.
If the MAC address is accidentally erased, for example during a reflash of the software, this
information is lost. If this happens, the Eddystone Instance ID transmitted in the C209 advertising
beacon will not match the MAC address of the module. To correct this:
1. Scan the QR code on the module label. The information in the code includes a code that includes
the MAC address (shown here in bold): H85(
CCF9578E0D89 )0400.
2. While having a debugger connected to the SWD interface of the board enter these commands to
reinstate the MAC address
CCF9578E0D89 into the UICR of the module:
nrfjprog --memwr 0x10001080 --val 0x8E57F9CC
nrfjprog --memwr 0x10001084 --val 0xFFFF890D
Another example for which the MAC address given in the scan code is 0123456789AB :
nrfjprog --memwr 0x10001080 --val 0x67452301
nrfjprog --memwr 0x10001084 --val 0xFFFFAB89
3. After writing the MAC address, reset the module. The module now transmits the correct
Eddystone Instance ID for the C209 tag.