Fake digital Input signal

[Franju]

Hello,

What about to try doing contact to the input with a cable connected to 12v, and after connected to 0V, and check if the eratic state of the input is gone ? If so, it would mean, I think, that you need a pullup or pulldown resistor, depending to your project.
Or maybe a switch connected for exemple NC to 12v and NO to 0V ?

• This reply was modified 4 years, 3 months ago by  Franju. Reason: orthographe

[tobiascapin]

Unfortunately I cannot have a SPDT switch to ground the signal when not pressed. Anyway finally I think I have solved using an extra external pulldown resistance of 10K.

I tryied to get direct support from Controllino, I had a first reply but I did not have any information related to internal resistence. The documentation has not information about this requirement and moreover has no information about the internal pulldown resistance value.

I’m really disappointed with the lack of documentation and of the support.

[Franju]

I think you can have a look on the Atmega 2650 microcontroller datasheet, as it is the one used in controllino Mega.
Still my opinion : the internal pullup resistance would be those of the Atmega. So its datasheet would tell you. And so there is no internal pulldown resistors.

[Lukas]

Hello,

each digital/analog input already has internal pull-down resistor as a part of the voltage divisor inside. The behaviour you describe seems to be caused by really high noise on the line. Nevertheless I will try to investigate it more.

Thanks,

Lukas

[tobiascapin]

Dear Lukas, I did not find the value of these internal pull-down resistors in the documentation.
By the way seems I have solved with an additional external 10k pulldown resistance, I agree the problem was an high noise due to the long wire.