ESP8266 Community Forum

- Sun Aug 07, 2016 4:41 am #52387 INTERRUPT Gotcha : it would be useful to mention in the Interrupt docs that the interrupt pin requires a hardware pullup (or pulldown) resistor added for it to work (which some dev boards may already include, but breadboarded ESPs do not).

Where to get modules?

https://www.banggood.com/custlink/KvGGhGF4wG

- Mon Oct 03, 2016 3:05 am #55990 Another one, from my experience; do not use gpio3 (normally Rx) as an interrupt pin, even if you dont need the serial io; Interrupt does not seem to work consistently, even with a pullup, although the same pin works fine if polled.

If anybody's found out otherwise, I'd like to know, so I could re-edit my list of gotchas.

- Mon Oct 17, 2016 6:35 am #56634 Hi Ardhuru,

A thought on your gpio03 interrupt inconsistency - floating inputs tend to float high, so when used for something, may have had a pulldown resistor added (typically 10K), in which case adding a similar value pullup would probably still leave the input in an indeterminate midway condition. Try using a 1K or 2K pullup and you might make the interrupt dependable.

I don't have time to waste unnecessarilly chasing shadows, so I'd be interested in having a peek at your Gotcha's list if that was possible?

Where to get modules?

https://www.banggood.com/custlink/KvGGhGF4wG

- Mon Oct 17, 2016 6:48 am #56636 Great point. Why didn't I think of that?!

I have indeed been using a pullup of 10k. I'll try lowering that today.

But how does that explain polling still working reliably, I wonder?