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What does the "state" pin do on the HC-05 Bluetooth module? Answered

Hi all,
What is the function of the state pin on the HC-05 6-pin serial bluetooth module?


What is this HC-05 5 pin module of which you speak ? HC-05s have about 30 pads.

Its an interrupt pin, according to the data I can find.

This pin is low while connection is off. When HC 05 is paired with another bluetooth this pin turn High, so if you connect it to an Arduino digital input you can monitorize the connection state.



I read the article you shared, but when I try it out on my hc 05, the state pin just stays LOW, regardless of whether it is paired to my android phone or not.

My hc05 module has a built in button ,and is marked zs-040, if that means anything.


The documentation says "paired", but it's wrong (my guess is a mangled translation by a non-techie). The State pin goes HIGH when you are connected, not just paired. That's a lot more useful.