Receiving Oregon Scientific sensors with RTL-SDR

Kevin Mehall got his RTL-SDR dongle and wasted no time in developing a decoder using GNU Radio for the 433MHz transmissions of Oregon Scientific remote temperature sensors (v1 protocol). These devices transmit on 433.9 MHz sending data packets containing the temperature data every 30 seconds. The transmitter uses On-off keying and the 32 data bits are manchester encoded. He uses the GNU Radio osmosdr block to capture signals from the dongle. This project uses GNU Radio from the command line, not the Gnuradio-Companion GUI.

You can find the source code and docs at Kevin Mehall’s GitHub page.

This entry was posted in code, open source, SDR, sensors and tagged , , .


  1. BH says:

    This is great, I’d like to get better at building GRC blocks to model common devices like this.

  2. Ed says:

    You can do the same with Lacrosse sensors which are even simpler: straight OOK transmission, no manchester encoding – been doing this for several years in my summer house to monitor temperature, wind, humidity, rainfall on the beach, you just need a tiny PIC and basic AM 433MHz receiver module to do this :-)

    • John says:

      I found a Lacrosse sensor at the manufacturer’s site: TX29U-IT Wireless Temperature Sensor $14.95 that says the battery life is about 24 months.

      Ed, could you provide a bit more detail about the components of your system? What parts and costs. And what software do you use?

  3. Jim Camarata says:

    I cannot get LaCrosse sensor TX6U-516 to communicate with my Oregon Scientific base station JTR168LR altho both are 433M Hz. Can anyone help?

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