[Friedl]

When you successfully verified the sensors output voltage, you can even
replace the sensor and the resistor with a lab power supply. This makes verifying your code much easier.

[Friedl]

You need to give the sensor “space to breath” (=enough voltage left), otherwise it just won’t work.

If you take this setup (from the product page):
https://www.calex.co.uk/site/wp-content/uploads/2020/01/pyromini-oem-connections-4-20-ma-1024×411.png
and add the 500 Ohm resistor across the +/- of the instrument shown in the picture, which would then be your Controllino, we can conclude:

1. 0,020 A * 500 Ohm = 10V
2. 0,004 A * 500 Ohm = 2V
3. 24V – 10V = 14V > 8V ! (24V power supply assumed)

And BTW (see datasheet):

Max. Loop Impedance
900 Ω (4-20 mA output)

Put aside your Controllino, only leave the resistor, take a digital multimeter and verify your setup first. When you know what voltages are to be measured, verifying what you measure with the ADC is much easier.

• This reply was modified 3 years, 1 month ago by  Friedl. Reason: Stray DIV tags from the editor again. (PLEASE FIX THIS)

[Friedl]

Did you take into account (see datasheet of sensor):

Minimum Sensor Voltage
8 V DC (all other models)

Therefore you’d be better off if you’d be using a MAXI Automation (0-10V input) and a 500 Ohm resistor.

• This reply was modified 3 years, 1 month ago by  Friedl. Reason: typo fixed

[Friedl]

Then may I suggest to at least support image links to your own forum website to show the image inline – like you do for eg. Imgur.

Images hosted on external platforms will break when time goes by.

For an example of a thread with images may I refer to the following post: [This Forum] Discrepancy in activity when logged-off vs. logged on

[Friedl]

I already thought that having both versiones installed could lead to problems and therefore I uninstalled all versions first and cleaned the “%localappdata” and “Documents/arduino” from all what remained from Arduino.

Then and I reinstalled the Arduino 2 Beta 3 IDE again.

At the moment I’ve given up, cleaned the system again and reinstalled the old version 1.8.3.

There’s real work to be done right now.

Can send you a photo of the setup in PM, if you’re interested.

[Friedl]

If my previous post wasn’t clear enough, please allow the user to make this field viewable to “Member, Public, Just Me”, as he wishes.

[Friedl]

Dear Jarda!

Regarding your suggestion of using the AREF pin.

If you open the microcontroller manual https://ww1.microchip.com/downloads/en/DeviceDoc/ATmega640-1280-1281-2560-2561-Datasheet-DS40002211A.pdf, there on page 9, chapter “2.3 Pin Descriptions” you can read:

AVCC is the supply voltage pin for Port F and the A/D Converter. It should be externally connected to VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass filter.

Therefore we can assume AVCC = VCC = 4.874V as measured before.

When you scroll down to page 365, chapter ” 31.8 ADC Characteristics” you will discover that:

Vref_MIN = 1.0V and Vref_MAX = AVCC

Because we know from above that AVCC = VCC, so AREF must always be less than or equal to VCC.

If VCC = 4.874V, as demonstrated before, then supplying 5V to AREF without supplying 5V to VCC as well is out of specification.

This suggestion could be dangerous, don’t you think so?

Greetings
Friedl

• This reply was modified 3 years, 2 months ago by  Friedl. Reason: typo

[Friedl]

Dear Jarda!

1) As shown above, the 0-10V inputs are nothing more than 2:1 resistive divider, correct? They are not documented in the manual nor on the pinout diagram.

2) If we’d switch to the 2.56V reference, we could only measure 0-5.12V (2.56V * 2), right?

3) Am I missing the secret pin to control the switch for the voltage divider on AI12 and AI13 from ratio 2:1 to ratio 3.90625:1?

Greetings from Graz
Friedl

• This reply was modified 3 years, 2 months ago by  Friedl. Reason: wording
• This reply was modified 3 years, 2 months ago by  Friedl. Reason: typo