I have a single outdoor DS18b20 sensor and I’d really like to have a physicallly wired connection back to a couple of NodeMCU’s running ESPHome.
I know you can have multiple DS18b20 sensors on a 1 wire bus back to a single NodeMCU, but I wonder if anyone had tried multiple NodeMCU’s on a 1 wire bus connected to a single or multiple DS18b20 sensors?
There is a reason for doing it… I’d like to build some redundancy in my setup, hence the reason for having multiple NodeMCU’s. Oh, and I want to avoid running wiring for multiple DS18b20 units.
My feedback: that’s a silly idea. You’d still have the sensor as a single point of failure, and you want to be able to read it reliably when it’s connected to multiple ESP units, some of which might have failed in undefined ways? I don’t think you’ve achieved any increase in system robustness there.
Just run another sensor separately if you need to: you could wire up several ESP / sensor pairs on a single run of Cat5 cable.
Consider putting the second outdoor sensor in a different location, then taking the minimum value as the actual temperature to reduce the effect of sunload. See here.
I’ve never had a DS18b20 sensor fail… ever. I take your point, but I wont be making my decision on the possibility of a DS18b20 sensor failing. I think I might still give it a go… experimenting is the best way to learn in my opinion. Thanks for taking the time to comment, much appreciated.
By all means try it. I just don’t think you’re adding anything, and may actually be making things less reliable. If you manage to successfully connect one sensor to two ESPs, but there’s a chance that when an ESP fails it takes the 1-wire bus with it, then you’ve increased the chance of system failure.
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