marxy's musing on technology

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How to see LoRa on an RTL-SDR waterfall

Posted: 04 Mar 2020 09:26 PM PST
http://blog.marxy.org/2020/03/how-to...waterfall.html

I've tried to see the LoRa chirps in the past but they were always too
quick. John, VK2ASU, has figured out how to slow down the chirps and spread
the spectrum enough to see this:




Here's the settings used:

LoRa.setSpreadingFactor(20);
LoRa.setSignalBandwidth(62.5E3);

Thanks John!


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Decoding a Digitech Wireless LCD Thermometer

Posted: 04 Mar 2020 09:33 PM PST
http://blog.marxy.org/2020/03/decodi...eless-lcd.html

Just picked up a AU$20Â*indoor/outdoor wireless thermometer from Jaycar. It
mentions on the back that it uses 433.9MHz so I connected an RTL-SDR and
ran the omni decoding rtl_433 command line tool. Simply installed using apt
on Ubuntu.




The remote FT-004-b temperature sensor sends a reading once every 60
seconds. There's a little LED that blinks just before it sends. Here's the
setup.