Dew heater pin control status.

[mducatmisathodotcom]

Hello,
I set up the dew heater module with these following settings:

The heating status is OFF but the relay GPIO pin is ON !
and the reverse occurs when heating conditions are met...

"AS_DEWCONTROLSENSOR": "DHT22",
"AS_DEWCONTROLAMBIENT": "22.9",
"AS_DEWCONTROLDEW": "2.77",
"AS_DEWCONTROLHUMIDITY": "26.7",
"AS_DEWCONTROLHEATER": "Off"

$ pinctrl get GPIO26
26: op -- pn | hi // GPIO26 = output

$ pinctrl get GPIO20
20: op -- pn | hi // GPIO20 = output

How to make the the GPIO output in accordance with the AS_DEWCONTROLHEATER status ?

Thank you
Michel

[Alex-developer]

Thanks for the detailed report, always nice to get lots of info.

Just to be clear on this part

and the reverse occurs when heating conditions are met...

Are you saying that when the heater should be on the gpio pins go low? If so try selecting the invert relay options and see if that resolves it.

If it does then we will have to dig a little deeper into whats going on

[mducatmisathodotcom]

Quote "Are you saying that when the heater should be on the gpio pins go low? "
Yes, that's exactly it !

I've already selected the reversing relay and it works, but I'm wondering why the GPIO pin isn't following the heating command's state.
It would make more sense if the GPIO pin went "On" when the command says "Start heating" and went back to "Off" when the command says "stop heating"...

Thank you !

[Alex-developer]

Quote "Are you saying that when the heater should be on the gpio pins go low? " Yes, that's exactly it !

I've already selected the reversing relay and it works, but I'm wondering why the GPIO pin isn't following the heating command's state. It would make more sense if the GPIO pin went "On" when the command says "Start heating" and went back to "Off" when the command says "stop heating"...

Thank you !

Thats exactly how its supposed to work, I cannot think of a reason why the gpio states would be reversed but a few things to check

1. Disconnect the heater from the pin and see if the results are the same, could be some strong pull up or down hardware causing it
2. Check /boot/firmware/config.txt for any lines that reference the gpio pins and see if there is anything setting the active state

Alex

[mducatmisathodotcom]

Hello,
As you suggested, I turned off the Raspberry Pi, unplugged the heater, and after turning the Raspberry Pi back on, the problem disappeared… After plugging the heater back in, the problem no longer appears.
The magic of computers!
Another question: do you know how to disable (set to none) the GPIO extra pin...?
do nothing !

[mducatmisathodotcom]

Another question: do you know how to disable (set to none) the GPIO extra pin...?
do nothing !

I change from Safari to Chrome and that work !

[Alex-developer]

Hello, As you suggested, I turned off the Raspberry Pi, unplugged the heater, and after turning the Raspberry Pi back on, the problem disappeared… After plugging the heater back in, the problem no longer appears. The magic of computers! Another question: do you know how to disable (set to none) the GPIO extra pin...? do nothing !

That will be a bug ! I'll take a look.

Weird how the pin inverted but fixed by a reboot !