induction problem

[on3adc]

Hello,

I have build a domotica system with a FEZ Panda and some velleman K8000 board cards.
The software i use is written by Bart Vanderhaegen.
This system runs perfect on 2 locations.
But on the 3 location it gives me large problems.
By an ukknow reason it swiths output on without a push on a button.
The communication between de FEZ Panda and the 3 K800 cards runs via I²C bus.
The lenght of this wires is max 50 cm.
To make a input on the K800 card you have to but 12V dc on a optocoupler and then the soft decide wich output to swith on.
I have connected al the GND together. The power supply is 12V DC and with a scopp i dont see any problems.
The only diffrent between the 3 installation is the housing of the whole system.
2 housings are made in Steel and the third is made from Plastic.
Can Anyone give me some tips to solve that problem.
I know its not easy but maybe 1 tip can help me further.

Many thanks Filip

 

[OLIVE2222]

Hi Philip,

Ok, let start with the docs:
http://www.velleman.eu/downloads/0/manual_k8000.pdf
http://www.bvsystems.be/k8000.php
https://www.ghielectronics.com/catalog/product/256

Is swapping the board 1(or2) with the board 3 give the same results?
Is it working OK with shorter cables?
Moreover the K8000 are designed to be connected on (obsolete) PC printer port via optocouplers. How do you connect the 3 boards on the same I2C bus? The FEZ board don' t looks to have an I2C buffer and you need to drive 3 (optocoupler) leds with, not sure if it's possible.

Olivier

 

[on3adc]

Hi,

Thanks for answering.
You can connect 4 boards together because every board has a own cardnumber.
I have 4 installations running with this configuration and 3 of them are working great.
First i gonna try to make the wires between the cards thiker.
But i think there is a induction problem from a device in the house.
Such problems are verry diffuclt to solve but i try al the possible solution one by one.
Good tips are always welcome.