Hey folks.
Unfortunately I worked at Danfoss for their wireless thermostat, not
Drayton. And that was many years ago.
I can offer some insight into the protocol though if that helps.
Simple FM transmitters much prefer a bitstream with equal quantities
of '0' and '1', as it makes it much easier for the receiver to track
the mid-frequency. This improves signal to noise, and therefore range.
Here are the two codes from above.
AA AC 59 99 59 55 59 56 AA
AA AC 59 99 59 55 95 65 AA
In binary, with bits paired up:
10 10 10 10 10 10 11 00 01 01 10 01 10 01 10 01 01 01 10 01 01 01 01
01 01 01 10 01 01 01 01 10 10 10 10 10
10 10 10 10 10 10 11 00 01 01 10 01 10 01 10 01 01 01 10 01 01 01 01
01 10 01 01 01 01 10 01 01 10 10 10 10
There are four symbols used. Lets call them A-10 B-01 C-11 D-00. Note
that if you stick to A's and B's, you always have pairs of 0 and 1.
This modulation method is known as Manchester Encoding.
Now the messages look like this:
AAAAAA CD BBABABABBBABBB BBBBA BBBBA AAAA
AAAAAA CD BBABABABBBABBB BBABB BBABB AAAA
A few features to point out:
The AAAAAA is a lead-in. It is sent whilst the receiver is locking
into the signal.
The CD is a sync pulse. It breaks the lead-in pattern, and ensures the
receiver knows how bits are paired. It deliberately breaks the '01' or
'10' rule to make detection easy.
The BBABABABBBABBB is the unit identification number. This is what is
learnt during pairing.
The BBBBA or BBABB is the on / off code. It is sent twice, once for
verification.
The AAAA is the lead-out, as the transmitter is switched off.
Just a random ramble - but hope it helps.
Peter