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Topic: Decode RF signal from Fine Offset WH-3080 weather station via YK-MX-5V receiver (Read 4645 times) previous topic - next topic

asmdsr

Hello,

I am trying to decode a signal from a Fine Offset WH-3080 weather station.  I have a YK-MX-5V 433Mhz RF receiver and an Uno.  Specifically I want advice on what libraries to use.

Progress so far:

1) I have followed these instructions  to sniff the signal using my sound card.   I can see the signal there, here's some screenshots:



2) I've run some code I found in this post to dump pulseIn() events to serial.  I can see the signal in the output.  I suppose if I kept hacking on this I could decode it myself.  But it seems like there must be good libraries to do this.  Any hints on how to get started?

Thanks in advance,
Tim

Riva


Any hints on how to get started?

Google  :D
Look up posts from mr.sneezy here. I have not registered with them to see the attached files etc but it reads well.
Also look here and here.
Don't PM me for help as I will ignore it.

asmdsr

Thanks for the reply Riva.

Firstly I should disclose that I am a bit of a newbie - while I have a lot of software experience, I'm new to arduino and hardware and embedded software and radio and signal processing.

Those links are helpful.  The mr.sneezy one is in the context of Cumulus, which makes it more useful for understanding the protocol, but not so much for getting the low-level arduino code to work, is that a correct assumption?  It did lead me to some memory maps which would be very useful, if I get to that point (having read a packet), then I'll be set.

So, I suppose what I need is a bit more help with some of the Arduino hardware and low-level code to do with talking to the device and decoding the raw signal.  The last link you sent is pretty close, but I have some questions about receivers and terminology and how it applies to my situation:
1) what is MCU
2) what is OOK
3) what is the difference between the devices such as YK-MX-5V and AUREL RX-4MM5 and RFM01 and RFM12B?  Are they interchangeable or is there some fundamental differences?  Should I be looking at getting a different device for this purpose?

Also, again about that last link, I'm a bit surprised that the code is so low-level.  It's basically doing a bunch of digitalRead calls and various delays to interpret the signal.  Isn't there some libraries that do this for you?

Thanks again,
Tim

Riva


Those links are helpful.  The mr.sneezy one is in the context of Cumulus, which makes it more useful for understanding the protocol, but not so much for getting the low-level arduino code to work, is that a correct assumption?
I did not register on the forum to see what stuff was attached to the posts but he hinted about receiving the RF data and what the various bits of the data mean.
The usual route for people wanting to receive and decode weather sensors like this (assuming nobody has done this before for the same sensors) is to grab the raw RF data (as you show in your first post), try to work out the encoding scheme for 0 and 1 bits and then work out what the assembled bits mean for each sensor/reading. It can be quite a long process but satisfying if/when you get it.


It did lead me to some memory maps which would be very useful, if I get to that point (having read a packet), then I'll be set.
I think the memory maps are for the receiving station and not the format of the RF data sent by the sensors.

So, I suppose what I need is a bit more help with some of the Arduino hardware and low-level code to do with talking to the device and decoding the raw signal.  The last link you sent is pretty close, but I have some questions about receivers and terminology and how it applies to my situation:
1) what is MCU = Micro Controller
2) what is OOK = On/Off Keying
3) what is the difference between the devices such as YK-MX-5V and AUREL RX-4MM5 and RFM01 and RFM12B?  Are they interchangeable or is there some fundamental differences?  Should I be looking at getting a different device for this purpose?
Different RF modules that may use different ways of connecting to the MCU and/or different ways of modulating the signals and/or different frequencies.
Your weather sensors look to be using OOK instead of FSK (Frequency Shift Keying) so the receiver you have should be okay.


Also, again about that last link, I'm a bit surprised that the code is so low-level.  It's basically doing a bunch of digitalRead calls and various delays to interpret the signal.  Isn't there some libraries that do this for you?
Any libraries you find would also be doing the same thing. As mentioned above the key is to work out what the different on/off signals mean and for OOK the duration of the on/off signals normally denote the bit type as zero or one.
Don't PM me for help as I will ignore it.

zoomx

MCU is the Microcontroller, the one that is in Arduino (in Yun there is another one with a Linux openWRT firmware)
OOK stand for On-off keying
http://en.wikipedia.org/wiki/On-off_keying
3) Sorry, I don't know, you must use a search engine.


BlackChart


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