weewx-sdr-ng

Fork of Matthew Wall's great project to get PRs merged faster and modernize the code.

This is a driver for weewx that captures data from software-defined radio. It works with open source rtl sdr software that in turn works with inexpensive, broad spectrum radio receivers such as the Realtek RTL2838UHIDIR. These devices cost about 20$US and are capable of receiving radio signals from weather stations, energy monitors, doorbells, and many other devices that use unlicensed spectrum such as 433MHz, 838MHz, and 900MHz frequencies.

Hardware

Tested with the Realtek RTL2838UHIDIR. Should work with any software-defined radio that is compatible with the rtl-sdr software. Uses the modules in rtl_433 to recognize packets.

Output from many different sensors is supported. To see the list of supported sensors, run the driver directly with the list-supported action.

If a sensor is supported by rtl_433 but not by weewx-sdr, it is a fairly simple matter of writing a parser for that sensor within weewx-sdr. Things are a bit more complicated if a sensor is not supported by rtl_433.

Prerequisites

Running installations of

• weewx
• rtl-sdr
• rtl_433

Installation

1. Install the driver with

weectl extension install https://github.com/an0nfunc/weewx-sdr-ng/archive/refs/heads/master.zip

2. Run the driver directly to identify the packets you want to capture. You need to be in the weewx install dir for this to work.

PYTHONPATH=. python bin/user/sdr.py --cmd="rtl_433 -M time:unix -F json"

3. modify the [SDR] section of weewx.conf using a text editor

   • create a [[sensor_map]] for the data you want to capture
   • possibly modify the cmd parameter

4. set [Station] -> station_type to SDR

5. (re)start weewx

How to run the driver directly

Run the driver directly for testing and diagnostics. For example, if weewx was installed using setup.py:

PYTHONPATH=/home/weewx python /home/weewx/bin/user/sdr.py --help

Configuration

Use the [SDR] section of the weewx configuration file (nominally weewx.conf) to adjust the driver configuration.

The default configuration uses this command:

rtl_433 -M time:unix -F json

Specify different options using the cmd parameter. For example:

[SDR]
    driver = user.sdr
    cmd = rtl_433 -M time:unix -F json -R 17 -R 44 -R 50

The rtl_433 executable emits data for many different types of sensors, some of which have similar output. Use the sensor_map to distinguish between sensors and map the output from rtl_433 to the database fields in weewx.

Examples

Acurite 5n1 sensor 0BFA and t/h sensor 24A4

[SDR]
    driver = user.sdr
    [[sensor_map]]
        windDir = wind_dir.0BFA.Acurite5n1Packet
        windSpeed = wind_speed.0BFA.Acurite5n1Packet
        outTemp = temperature.0BFA.Acurite5n1Packet
        outHumidity = humidity.0BFA.Acurite5n1Packet
        rain_total = rain_total.0BFA.Acurite5n1Packet
        inTemp = temperature.24A4.AcuriteTowerPacket
        inHumidity = humidity.24A4.AcuriteTowerPacket

Acurite 986 fridge/freezer sensor set 1R and 2F

[SDR]
    driver = user.sdr
    [[sensor_map]]
        extraTemp1 = temperature.1R.Acurite986Packet
        extraTemp2 = temperature.2F.Acurite986Packet

Acurite 06002RM t/h sensor 3067

[SDR]
    driver = user.sdr
    [[sensor_map]]
        inTemp = temperature.3067.AcuriteTowerPacket
        inHumidity = humidity.3067.AcuriteTowerPacket

Hideki TS04 sensors with channel=1 and channel=2

[SDR]
    driver = user.sdr
    [[sensor_map]]
        outBatteryStatus = battery.1:9.HidekiTS04Packet
        outHumidity = humidity.1:9.HidekiTS04Packet
        outTemp = temperature.1:9.HidekiTS04Packet
        inBatteryStatus = battery.2:9.HidekiTS04Packet
        inHumidity = humidity.2:9.HidekiTS04Packet
        inTemp = temperature.2:9.HidekiTS04Packet

Fine Offset sensor cluster with serial number 0026

[SDR]
    driver = user.sdr
    [[sensor_map]]
        windGust = wind_gust.0026.FOWH1080Packet
        outBatteryStatus = battery.0026.FOWH1080Packet
        rain_total = rain_total.0026.FOWH1080Packet
        windSpeed = wind_speed.0026.FOWH1080Packet
        windDir = wind_dir.0026.FOWH1080Packet
        outHumidity = humidity.0026.FOWH1080Packet
        outTemp = temperature.0026.FOWH1080Packet

To figure out the sensor identifiers, run the driver directly, possibly with the --debug option. Another option is to run weewx with the logging options for [SDR] enabled to display the sensors found by rtl_433, the sensor identifiers used by weewx, and the sensors actually recognized by weewx.

[SDR]
    driver = user.sdr
    log_unknown_sensors = True
    log_unmapped_sensors = True

By default, the logging options are False.

How to diagnose problems

First try running the rtl_433 application to be sure that it works properly:

rtl_433

If you know exactly which sensors you want to monitor, try the -R option to reduce the clutter. For example:

rtl_433 -M time:unix -F json -R 9 -R 31

Once that is working, run the driver directly to be sure that it is collecting data from the rtl_433 application:

PYTHONPATH=/home/weewx python /home/weewx/bin/user/sdr.py

Environment

The driver invokes the rtl_433 executable, so the path to that executable and any shared library linkage must be defined in the environment in which weewx runs.

For example, with rtl_433 and rtl-sdr installed like this:

/opt/rtl-433/ /opt/rtl-sdr/

one would set the path like this:

export PATH=/opt/rtl-433/bin:${PATH}
export LD_LIBRARY_PATH=/opt/rtl-sdr/lib

Typically, this would be done in the rc script that starts weewx. If rtl_433 and rtl-sdr are install to /usr/local or /usr, then there should be no need to set the PATH or LD_LIBRARY_PATH before invoking weewx.

If you cannot control the environment in which weewx runs, then you can specify the LD_LIBRARY_PATH and PATH in the weewx-sdr driver itself. For example:

[SDR]
    driver = user.sdr
    cmd = rlt_433 -M time:unix -F json
    path = /opt/rtl-433/bin
    ld_library_path = /opt/libusb-1.0.20/lib:/opt/rtl-sdr/lib
    [[sensor_map]]
        ...

libusb

I have had problems running rtl-sdr on systems with libusb 1.0.11. The rtl_433 command craps out with a segmentation fault, and the rtl_test command sometimes leaves the dongle in a weird state that can be cleared only by unplugging then replugging the dongle.

Using a more recent version of libusb (e.g., 1.0.20) seems to clear things up.

Detecting new sensors

After you have run for a while, you might want to add new sensors to your system. If you have more than two or three sensors, it can be quite a challenge to pick through all the output when you run the driver directly. This shows how to display only sensors that are detected but not yet part of your weewx configuration.

First, shut down weewx so that you can talk to the SDR directly.

Then run the SDR driver directly, but tell it to print out information only about sensors that you have not yet added to your weewx configuration:

PYTHONPATH=/home/weewx python /home/weewx/bin/user/sdr.py --config /home/weewx/weewx.conf --hide=out,parsed,mapped

As always, unless the sensor identifier is marked on the sensor itself, you should turn on sensors one at a time, marking the outside of the sensor with its identifier. Then you can turn on all the sensors and place them, using the identifier on the sensor to distinguish which sensor is which when you map them to database fields in your weewx configuration.

Support for new sensor types

To add support for new sensors, capture the output from rtl_433. To capture output, run the driver directly and hide known packets:

PYTHONPATH=/home/weewx python /home/weewx/bin/user/sdr.py --cmd "rtl_433 -M time:unix -F json" --hide parsed,out,empty

This should emit a line for each unparsed type. For example:

unparsed: ['{"time" : "2017-01-16 15:44:51", "temperature" : 54.140, "humidity" : 34, "id" : 221, "model" : "LaCrosse TX141TH-Bv2 sensor", "battery" : "OK", "test" : "Yes"}']

If you are not comfortable writing your own parser, open a new issue with the output and some helpful person might write the parser for you.