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Section 5 ism band decoder
The licence-exempt ISM bands are full of small unattended transmitters: weather and soil sensors, water and heat meters, doorbells, thermostats, alarm contacts, tyre-pressure sensors, gate remotes. Each one wakes up, sends a few milliseconds, and goes back to sleep for a minute. The ISM button in the System module opens a window that reads them and lists each device it has heard, with its readings in real units.
That button turns green while the decoder is running, not while the window is open — like SAT and SCAN, because it is spending a receiver on your behalf whether or not you are watching. Closing the window therefore leaves it lit. The switch is DECODING inside the window itself.
There are two sets of decoders behind that window. SDRoxide's own read a handful of protocols on the European 868 MHz channels, in detail and with every checksum verified — those are what the rest of this section describes first. The rtl_433 decoders (§5.4) add several hundred more across 315, 345, 433, 868 and 915 MHz. Most people will want both switched on.
- DECODING / OFF switches the decoder on. It costs four downconverters and a burst detector while it runs, so the ISM button stays lit — like SCAN and SAT — whenever it is decoding, whether or not the window is open.
-
sql is how far above the channel's own noise floor a transmission has to
stand before it is decoded. The default
12 dBis well below where these protocols stop working, so it is not what limits sensitivity: it is what stops the detector opening on noise. Lower it if you suspect you are missing a distant sensor; raise it on a noisy site. - The family buttons — WEATHER, METERS, HOME, LORA — choose what to listen for. Only WEATHER is implemented so far; the others are drawn greyed out rather than hidden, because those devices are on the air whether or not SDRoxide can read them yet.
From the User Manual. Home.