Meanwhile I have found a datasheet where they say the lines can be up to 30m or even longer. So the wire length should not be a problem.
About the condensing conditions, this is what I will be looking for to safeguard the roof.
If it happens I need to increase ventilation.
I did not know about the problem for the sensor...
I have breadboarded one sensor with a 47K pull-up to +5V and sensor driven with 5V for testing.
But I do not see the expected 40-bit transfer after I briefly pull down the data line to ground.
Is there some requirement that the start pulse must be a certain length or with a certain rise/fall time?
Or happen within a certain time from power-up?
I am just now pulling down with a grounded wire which I touch the resistor with.
A digital scope is connected to the line and all I see is the pulse I make myself, no data from the sensor...