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The inside of the ws-1081

Discussion specific to Fine Offset and similar rebadged weather stations
Posts: 8
Joined: Sun 20 Nov 2011 9:50 pm
Weather Station: WH-1081
Operating System: Debian
Location: Edinburgh

Re: The inside of the ws-1081

Post by ksangeelee »

AllyCat wrote: Personally, I don't have an RPi but as it appears you've posted the source code, perhaps someone else will be able to analyse some of the "other" protocols. The x080 models transmit the Radio Controlled Clock data as well, and the 308x models transmit solar data in a separate packet (with 60 seconds repetition rate). That might be easier to decypher (now that you've cracked the basic data format) because the Solar Pod encodes the data packet to send to the transmitter, so it can be read (on the Solar Pod cable) even without a radio receiver.
I expect it could be used to analyse most OOK-like signals on frequencies the RFM01 supports, given a bit of experimentation if the bit-rate is completely unknown. My original logic-analyser capture helped an awful lot though, since I then knew what I was looking for on the receiver side.

The bit of code that captures transitions on the DATA pin into 'rssitime_buf' is more or less all that would be needed, other than the hardware setup code. That buffer name is a bit of a misnomer - it was originally based on the RSSI state, but that wasn't a very reliable way of doing it - I should have renamed it 'highduration_buf'.

Also, for anyone who might use the code to investigate other data packets, be aware that I throw away all 'low->high' transitions, because these are just the (1ms) clock pulses in my WH1081 transmitter. For a true OOK signal, you'd want to include these in the buffer too (or have a corresponding 'lowduration_buf').

Thanks for the tip on getting rain readings - saves me running back and forth with a watering can!

Posts: 11
Joined: Mon 12 Mar 2012 11:22 am
Weather Station: WH1080
Operating System: Windows Vista
Location: Belgium

Re: The inside of the ws-1081

Post by TomV »

hmm... on top if the black blob there is "SPL191B1".

Googling it gives us that SPL191B1 is a Sunplus 8-bit CMOS microprocessor with 256K ROM (to store the program - can we read it?) and 704 bytes RAM and 20 I/Os
There is probably info to be found about Sunplus SPL191B, like datasheets, but they don't seem to be accesible for free.
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