Firstly sorry for yet another 1 wire network troubleshoot topic. I've read a book worth of them but I'm under the impression that none of the information there helps my case.
Situation: I'm building a solar water heater that can dump its excess water into my pool. Therefore I need 10 temperature sensors connected to my PI read at 1 minute intervals. The network is quite long as the components of the system are spread out.
Build: I've researched before I wired everything and had experience with failing 1 wire networks before. Online I found that a ring network would provide the best behavior. In this ring network there are 4 hubs where 1 metre senors depart from. The wires I used a re bit of a mix & match but are comparable to jumper cable size. The network is close to AC mains cables in some cases for a total of about 5 meters of network length. Some wires were thicker, I recently replaced these as it might increase capacitance. I am still awaiting the results. However I'm skeptical this will amount to much as its only 5 meters of total length in the network.
Stability: This network has worked perfectly for 2 months to my happy delight. Thereafter it started failing. The failures happen randomly after 1 hour, 4 hours or a couple of days. The strange thing is a reboot doesn't help, even pulling the power, I need to pull the entire psu from mains. To debug the system I tried different resistors and psu's/powerbanks all to the same effect. I ended up with a 2k2 resistor placed closest to the pi.
How it fails: As said above after a random while Some or all sensors start reading 85.0 as a temp value. Then after 2 minutes all devices in the network disappear and 2-3 ghost devices appear. A hard reboot by pulling the psu is needed.
I would very much prefer a stable network otherwise I don't have hot water to shower with and the wife acceptance factor diminishes
I was thinking of splitting the network in two. I thinks its likely that I'm pushing the limits of what a network can handle.
As far as I know there are 2 options:
- Adding a second network to the pi by defining a new gpio as described here: viewtopic.php?t=156734
(My understanding is that these networks are separate)
- Using a DS2482 I2C to 1-wire this creates a separate network and communicates over i2c.
I would prefer solution 1 as this is the fastest & cheapest to implement but I need to be sure these networks are seperate. I'm very much looking forward to advice. Thanks in advance!
A sketch of the network: