Meter - SDR RTLAMR
Kismet can leverage the cheap rtl-sdr software defined radio to capture the output from several power, water, and electrical meter brands which broadcast usage rates at 915MHz.
The SDR RTLAMR source can autodetect rtl-sdr devices automatically, and can be manually specified with type=rtlamr:
source=rtlamr-0:type=rtlamr
Supported hardware
The RTL-SDR is a repurposed digital TV tuner which functions as an extremely cheap SDR, or software defined radio.
The Kismet implementation of AMR decoding is tightly coupled to the cheap RTL-SDR, and currently will not work with other SDR hardware.
It is not possible to use Bluetooth or Wi-Fi devices to capture RF meter data; a SDR is required for tuning to the proper frequencies and capturing raw radio sample data.
SDR RTLAMR interfaces
Kismet identifies RTL-SDR hardware by either the serial number (if any) or by the radio position; for example:
The first RTL-SDR radio in the system, to be used for rtlamr:
source=rtlamr-0
A specific RTL-SDR radio (if serial numbers are available):
source=rtlamr-324452324332
Not all RTL-SDR hardware populates the serial number field, and some hardware ships with a default serial number of 0.
Serial numbers can be found using the standard rtlsdr tools, like rtl_test:
$ rtl_test
Found 4 device(s):
0: NooElec, NESDR Nano 3, SN: 2686186936
1: NooElec, NESDR Nano 3, SN: 1177459274
2: NooElec, NESDR Nano 3, SN: 2664167682
3: NooElec, NESDR Nano 3, SN: 0572734167
Multiple RTL-SDR devices
Every datasource in Kismet must have a unique identifier, the source UUID. Kismet calculates this using the serial number of the RTL-SDR device.
Not all RTL-SDR hardware supplies a valid serial number; often devices will report a serial number of “00000000”. This will not cause any problems for Kismet if it is the only RTL-SDR device, however when using multiple RTL-SDR radios either locally or via remote capture, each one must have a unique ID.
A unique ID can be set using the rtl_eeprom tool to assign a proper serial number, or by using the uuid=... parameter on the Kismet source definition. A unique UUID can be generated with the genuuid tool on most systems.
SDR RTLAMR source parameters
Naming and description options
All data sources accept the common naming and description options.
Channel control options
channel={ frequency-in-Hz }
By default, SDR RTLAMR will tune to 915MHz. To manually set the frequency, in Hz;
source=rtlamr-0:channel=512000000
Radio control options
biastee={ true } / { false }
Enable bias-tee power on supported radios.
Bias-tee is used to supply power to external amplifiers or other equipment in the antenna chain, and requires that your radio hardware has power injection support.
gain={ value }
ppm={ error_value }