Controllino MEGA - Irregular Resets

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fragglecam
Posts: 2
Joined: Thu Nov 21, 2019 8:55 pm

Controllino MEGA - Irregular Resets

Post by fragglecam » Tue Jun 02, 2020 2:40 pm

Hello,

I'm using a Controllino MEGA in a HeatingControl Szenario with several Pumps, Vents and a lot of OneWire Temp-Sensors.
Except of the Temp-Sensors everything is controlled by 24V (Inputs/Outputs) or 230V (Relay Block B) - Block A is not used so far.
The 20 OneWire Sensors (DS18B20) are connected in 5 Buses to the PinHeaders (Arduino Pins 10,16,17,20,21), as their signal is 5V based !

Since the installation there were irregular Resets of the Controllino.
After a lot of research I found out that it was a combination between two issues:
  • The /Reset-Pin (Pin 11 on X1 and X2) has only 3,7 V ! It should be pulled up to 5 V - isn't it ?
    I measured the Short-current (ResetPin against GND) of 0,6 mA - which means there is a Pullup of about 7k present !
    Is there any other circuit connected to the reset pin, which can bring the voltage down ?
  • There are some interferences coming from the 1-Wire buses - These finally triggered the reset from time to time.
After knowing all that, I pushed the /Reset with another external 1k Resistor to 5V, and the Resets have gone !

But this is not the solution ! Any ideas ?

Frank

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Jarda
Posts: 45
Joined: Fri Dec 14, 2018 10:52 am

Re: Controllino MEGA - Irregular Resets

Post by Jarda » Wed Jun 03, 2020 11:15 am

Dear Frank,

Please use the solution with External 1 kOhm resistor.
There is no risk of damage of the CONTROLLINO.

BR
Jarda

fragglecam
Posts: 2
Joined: Thu Nov 21, 2019 8:55 pm

Re: Controllino MEGA - Irregular Resets

Post by fragglecam » Wed Jun 03, 2020 12:13 pm

Hi Jarda,

thanks for your reply, but could you please explain, how this could be ?
What kind of circuit is in there that cause this voltage drop - or is it defective ?
On my other Units (MINI and MAXI Automation) I have full 5V in the /RESET Pin !
Unfortunately I don't have another MEGA here to check that ...

Frank

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Jarda
Posts: 45
Joined: Fri Dec 14, 2018 10:52 am

Re: Controllino MEGA - Irregular Resets

Post by Jarda » Thu Jun 04, 2020 12:23 pm

Dear Frank,

your CONTROLLINO is not destroyed and this is behaviour of the MEGA variant only due to the connection of more ICs to /Reset line (higher current consumption via pull-up).

With this configuration we have passed EMC imunity test, but we are going to improve it in the next production lot.

Thank you for your feedback.

Regards
Jarda

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