There is option to connect rain sensor ?

[zenonmb]

Colleagues,

An update on this topic, since I did as suggested (connecting 10K pull up + 4k7) and noticed same behavior as mikcaau mentioned. Investigating the logic levels, it turn out that the 4k7 R is too high (combined with 10K). With the suggested set up, V rain = 1V (aprox),and anything above 0.8V is considered ambiguous (not guaranteed, for a 3.3v power supply) .
I like the idea of a protection and thus a serial R , but the value should be lower . Like 1K or similar (with 10K pull up) .
Cheers,

martin

[Ray]

The current OSPi design no longer uses external pull-up — it relies on RPi’s internal pull-up resistor, which is about 50~60K ohm. So 4.7K series resistor is fine with internal pull-up.

[Author]

Posts