UBX-21004616 - R02
Contents
Page 18 of 28
C1 - Public
C209 tags are simply configured over the UART interface using AT commands.
The AT commands that can be used to configure the interface are described in Table 4.
Command
Description
AT+UMLA=1
Read Local MAC address
AT+GMM
Read the model identifier, will be NINA-B4-TAG
AT+TXPWR
=<valid_tx_power> <valid_tx_power> can be one of: -40, -30, -20, -16, -12, -8, -4, 0, 2, 3, 4, 5, 6, 7, 8 (dBm)
Table 4 C209 AT commands
☞
For
+TXPWR
to take effect the software must be reset, by pressing the reset button or power cycling
the module. The configuration is persistently stored in flash.
All commands are echoed and responded with either
\r\nOK\r\n
or
\r\nERROR\r\n
, and should be
terminated with
\r.
☞
The UART interface is available for 10 seconds after reset with the settings 115200 bps, with no
flow control.
4.2.2
Enabling/disabling advertising
Press and hold the C209 button for ~3 seconds to enable/disable advertising. If the tag is advertising,
press and hold the button to stop it advertising. The onboard RGB LED blinks blue when advertising
is enabled. The blinking interval correlates to the advertising interval.
4.3
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:
4.
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.
5.
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
6.
After writing the MAC address, reset the module. The module now transmits the correct
Eddystone Instance ID for the C209 tag.
