How can I read out the MAC address from a BLE module during test/production?

A fast and convenient way to read out the MAC address of each module during a test/production process would be through SWD from FICR (Factory information configuration registers) registers DEVICEADDR[0] and DEVICEADDR[1]. The following command will read the MAC address from our BLE modules:

nrfjprog --memrd 0x100000A4 --w 8 --n 6

Please note that reading the MAC address with nrfjprog will give the raw register content whilst using the SmartBASIC command ATI 4 (or by using sd_ble_gap_address_get() from nRF SDK) will automatically set the highest two bits to '11', since this is a requirement by the BT specification!

Please also note that reading from memory through SWD will halt the CPU. If you need your application firmware to start afterwards (like for performing some test sequence) you would have to run the CPU with

nrfjprog –run

More information on FICR registers are available in the respective data sheets, like this for nRF52840 / BL654.