"...the 1-wire devices look ideal but i've read a lot of problems with large 1-wire networks. Did anynoe use them on scale like this? " - Our boards are equipped to handle two 1-wire devices, but I will say this. Make sure that you use NON-BLOCKING code for these one wire devices, otherwise you will be wasting valuable CPU time just waiting for the sensor to read. Most of the example 101 code out there uses blocking code which is a huge pet peeve of mine. blocking code is never practical in real world applications. It's the de-facto standard for teaching it seems.

 

This might be way off, but but I wonder if a system made for measuring temps in a large, full grain bin would work. A thermocouple is about every 6' in all X Y Z directions. There can be up to hundreds of TCs all wired up to an interface, and monitored by software. Wireless interfaces are also an option.

The physical wiring layout can be modified to suit a variety of ideas for how you might want it to cover a certain patch or stretch of ground surface. (Or buried)

 

This might be way off, but but I wonder if a system made for measuring temps in a large, full grain bin would work. A thermocouple is about every 6' in all X Y Z directions. There can be up to hundreds of TCs all wired up to an interface, and monitored by software. Wireless interfaces are also an option.

The physical wiring layout can be modified to suit a variety of ideas for how you might want it to cover a certain patch or stretch of ground surface. (Or buried)

I don't see why not. The below image is about 20 years old. I had 24 T/C inputs lower right. I could just as easily had 100 or more.


All the thermocouples were Type K ungrounded using three wire including the shielded extension wire cables. Temperatures ranged from ambient about 70 F to 1,000 F. Long before this companies like Hewlette Packard and Omega were making dedicated T/C scanner systems with as many channels as you could want.

Anyway, yes it gets away from one wire.

Ron

 

I would try a LPWA connection using ISP4520. The only wiring you need to do is two wire power cable.