DHT11 on Analog A5 NOT working

[Hatchcross]

Hi All,

I’m quite puzzled with my setup. I have a few Photons which have several DHT11’s connected to them, originally connected to D4 & D5 and displaying without issues.

I have recently needed to utilize D0 through D7 so I have coded the existing Pins to Analog ‘A4’ & ‘A5’ for the DHT11(s).

Analog ‘A4’ displays the Temperature/Humidity just fine but I get no readings from Analog ‘A5’? I have tried different sensors but am not getting anything to display using ‘A5’, what gives?

I continue to struggle to understand why only ‘A4’ works and why ‘A5’ does not, I have even tested ‘A0’ and still cannot get a reading.

I spent endless nights the past week trying all combinations of hardware and code and simply cannot figure out why it won’t display.

Any input would be great.

-Hatch

[ScruffR]

Which library are you using?
If the library uses interrupts to read the data stream you need to use pins that do support interrupts. On the photon the pins D0 and A5 do not
For example the PietteTech_DHT library even states the need for interrupt enabled pins in the leading comment

// With this library connect the DHT sensor to the interrupt enabled pins
// See docs for more background
//   https://docs.particle.io/reference/firmware/photon/#attachinterrupt-

Device OS API | Reference Documentation

And on these pins you cannot use interrupts concurrently

[Hatchcross]

Hi ScruffR

I’m using “#include <PietteTech_DHT.h>”

Dang, that is quite the error on my part assuming A5 could have been used, which of course is not allowed…

I can reroute my wiring to A1-A4 as needed but that was a big mistake on my part. Spent way too much time trying to figure this one out…the hard way.

Thanks for the help.

-Hatch