sparslog

https://github.com/ThomasHabets/sparslog

Log power meter data from an IKEA Sparsnäs, by sniffing the radio communication from the sensor to the display.

The communication is one-way, so once you start logging you'll no longer need the display. Unless you like it, of course.

What you'll need

An RTL SDR dongle. Any one will do. This is hardly a demanding protocol.

Of course the better the SDR you have, the more distance and noise you'll be able to handle.

The packets are digital, so if the CRC is correct, then the data is very likely correct.

You'll also need the serial number of your transmitter. It's under the batteries in the device that attaches to the electricity meter.

Running the decoder

Where 123456 is the serial number of your transmitter:

$ cargo build --release
$ ./target/release/sparslog -s 123456 --rtlsdr

It'll print stuff, and log to sparslog.csv.

The format is timestamp,sequence_number,watts,kwh,battery_status,CRC_status

Decoder with tokio-console

This requires both the tokio_unstable config in RUSTFLAGS and the tokio-unstable feature.

$ RUSTFLAGS="--cfg tokio_unstable" cargo build \
    -F tokio-unstable \
    --release

Bonus feature: A GNURadio implementation

There's also a GNURadio implementation in the gr/ directory.

Related projects

• Technical analysis
• Simple implementation