Hi to all, i'm using udoo with an optoisolated relay board for an autofiller water tank. I'm using also an i2c display, it works quite well when used alone, but every time a relay is energized, the display starts showing strange characters udoo until it stops. I tried to use udoo without display and relays work without problems and without udoo locks. So I tried to use shielded control cables (for the relay), I tried to change the display i2c, I tried to filter the input current with capacitors (for decoupling), but was not able to run the relay along with the display . They are about 2 months since I stopped at this point and I do not know how to go on ... Have you any suggestions? attached you can see the display used. Thank you.
Does the relay have a diode across the coil to stop back emf ? , or is a just a voltage drop spike causing your problem.