Temperature sensors disappearing

[Dewd]

Hi

Had my RoboTank setup running for a while now with 2 x genuine Maxim sensors on standard length cable taking in-water readings.  The sensor tips are additionally encased in hot glue and heatshrink to further insulate from salt water.  I then have a third no-name brand sensor taking room temp reading in air.

What has been happening recently is that all 3 sensors will disappear.  So temp graphs and current temp readings drop to 0.  Additionally and of more concern is that equipment being controlled, respond as though the temp reading is 0.  So the heaters come on and stay on.  When the sensors "disappear", they do not show up as sensors to choose from in the temperature control section.

No re-loading or re-booting makes a difference.  But if I unplug the sensors from the controller and re-plug in, temp readings appear again.  But then disappear againat some random period later.

I have read threads where people have similar issues, but no definitive answer to what I can do to resolve the issue.

Any help would be appreciated.

Thanks

[Rob F]

Hi Des, I'm very sorry I haven't replied yet. Just seeing this now. :( Always best to send me an email if I don't respond here in a day or two.

Are you still experiencing an issue?

I think you have v1 controller? If so the 3 temp ports on the controller share the same GPIO which is why they all go down at the same time. It'll likely be one of these reasons.

Cable for each sensor is too long. As they share the same GPIO the 3 sensors creates a star pattern rather than 3 sensors being close to the same main line which isn't ideal.

One sensor is faulty and because they share GPIO when that one goes out the others are affected. Have you tired plugging in just one sensor, see how it runs and repeat with other sensors until you find the sensor causing the issue.

I've since changed it so each temp port has it's own GPIO.