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tommybobbins / Raspi_433

Using a Raspberry Pi to control a 433MHz sender chip attached to GPIO pin 18.
GNU General Public License v2.0
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(RfI) How did you reverse engineer the signalling protocol used? #1

Open ghost opened 8 years ago

ghost commented 8 years ago

I have a perfectly working Honeywell relay (BDR91) which I would like to use rather than reinventing the wheel. I wondered if you could tell me/us all a little about how you found the protocol your relay uses/expects to receive.

Thank you.

Al.

tommybobbins commented 8 years ago

Hello Al,

There are two ways I used to sniff the packets. The first method I used was using a £0.99 433 receiver and two resistors and a soundcard with line in: http://reversemidastouch.blogspot.co.uk/2013/09/work-in-progress-controlling.html You can use audacity and reverse engineer the amplitude modulation. Some images are here too: https://www.rosslug.org.uk/2013/07/30/meeting-22nd-july-2013-home-automation-with-the-raspberry-pi/

The other way is to invest in a £10 DVB tuner and sniff the codes that way: http://goughlui.com/2013/12/20/rtl-sdr-433-92mhz-askook-decoding-of-various-devices-with-rtl_433/

The full project that the 433 sender ties into is this: https://github.com/tommybobbins/PiThermostat http://reversemidastouch.blogspot.co.uk/2015/11/update-to-central-heating-system-using.html

I have since scrapped the ESP8266's for remote temperature sensors (as they are terrible at deep sleeping) and am using 6 wireless things devices: http://reversemidastouch.blogspot.co.uk/2016/07/wireless-things-temperature-sensors.html

ghost commented 8 years ago

I am so sorry it had taken me so long to get back to say thank-you. Ideal answer, sir. Thank-you very much.