Davis Weather Wizard - Hacking the Serial Port - Pt.2.5

Hummm... This is getting interesting.  I got curious why when I measured these signals sometimes P2 would be +5V others it would toggle to 0V ( or darn near)   I have now stumbled onto a pattern:

Weather Link connector {Wire colors match w/ signals 3/12}




 

So here is the deal....When I cycle P2 ( GREEN wire)  4x  then P1( YELLOW wire) toggles to voltage level 0V ( could be logic "1" I don't know yet) on the fifth cycle it returns to +5 V.  The pattern is very repeatable, I still don't know what this means yet or if it is even significant.  ...Just sayin'

UPDATE: The signals now match the wire colors to avoid confusion 3/12/12

Davis Weather Wizard - Hacking the Serial Port - Pt.2

Wizard still sleeps!  I have not devoted too much time to this,  but since the last post,  there has been some new info found! 

While it is still not spewing serial data my little modem can digest and convert int WX packets,  I have done more measurements, on TWO separate devices and the results are very similar.

First, I want to say that the signals I measured with my DVM were not entirely correct. I am not sure if I had a loose connection or what happened but here are the latest measurements:

WW3 Weatherlink Signals -- Updated

These hold true on two units!  The second is a $10 eBay find, I wanted one for my lab anyway and now I don't have to keep moving and resetting the existing unit in the family room.

So we can see P1 and P2 are TTL signals and P2 seems to be toggling, at least once after power up. It comes up near 0 V and toggles to +5V. I tried to tie each signal to GND and then to  a +5V source thru a resistor and finally a loop back as well (shorted the two signals) cycling the unit's power between each setup...

But, I never heard the happy "THIRD" beep that says you have a valid dongle attached.  I was hoping this would be the first breakthrough! But until now, only two beeps. Rats.

Stay Tuned!

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