This page attempt to document the low-bandwidth disaster recovery mesh (DisasterRadio).

UHD gain selection

The command:

 sudo uhd_find_devices

Should list the gain range for the TX or RX frontend of choice.

E.g. for the WBX TX frontend you get:

 Gain range PGA0: 0.0 to 25.0 step 0.1 dB

Make sure you're not looking at the gain range for TX when you're looking to receive or vice-versa, as the won't necessarily be the same!

GNU Radio UHD device selection

For a USRP 1 this should be in the form: serial=<hex_serial>. E.g:

 serial=24e6b31a

To find device serial run:

 sudo uhd_find_devices

You're looking for output that looks like:

|     _____________________________________________________
|    /
|   |       Mboard: USRP1
|   |   serial: 24e6b31a

To set the sub-device (the daughterboard and channel) use the format:

 <slot_name>:<daughterboard_frontend_id>

E.g:

B:0

This slot_name and daughterboard_frontend_id are also findable with the command:

 sudo uhd_find_devices

The output you're looking for looks like:

|   |     _____________________________________________________
|   |    /
|   |   |       RX Dboard: B
|   |   |   ID: WBX, WBX + Simple GDB (0x0053)
|   |   |     _____________________________________________________
|   |   |    /
|   |   |   |       RX Frontend: 0
|   |   |   |   Name: WBXv2 RX+GDB
|   |   |   |   Antennas: TX/RX, RX2, CAL
|   |   |   |   Sensors: lo_locked
|   |   |   |   Freq range: 68.750 to 2200.000 Mhz
|   |   |   |   Gain range PGA0: 0.0 to 31.5 step 0.5 dB
|   |   |   |   Connection Type: IQ
|   |   |   |   Uses LO offset: No

Specifically the lines:

|   |   |       RX Dboard: B

and:

|   |   |   |       RX Frontend: 0

Together making up the B:0.

For command-line python scripts

For command line scripts, device and sub-device is often specified with the --args and --spec arguments. E.g:

 my_script.py --args serial=24e6b31a --spec B:0

This syntax may vary from script to script, but this is the most common syntax.

For GNU Radio Companion

For the "UHD: USRP Sink" in the latest version of grc (as of this writing) the field "Device Addr" would be set to e.g. serial=24e6b31a and the field "Mb0: Subdev Spec" would be set to e.g. "B:0".