Temco bacnet weather station

How far can I extend this wire? I need to go 30 feet up to the roof. There are 5 wires that I can extend with 18/5 tstat wire (same colors)

Not the ethernet, the 5 conductor black cable pictured between the display and the sensor that is like 5 feet long. I want to splice the 5 conductors and add 25 feet to keep the display on the wall in my classroom and the sensor up on the roof and I’m wondering what will happen.

The cable to this sensor is using an I2C protocol which is unfortunately only good for about 3 meters [10 ft].


The students and I did an experiment because we really wanted the display on our controls wall and the weatherhead on the roof. We added 30 feet of cat6 to the 5 foot cable and it didn’t work, so we rerouted the wire carefully and cut 10 feet off so 25 feet max works! We soldered and heat shrinked ever so carefully.

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That is good to know, we will do some testing and quite possibly update our documents to show the extended length.

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I read i2c worked 20-25 feet max using twisted pair cat 5/6 at a slow baud rate. Can the user slow down the baud rate on this weather station if they want to extend wire? If you can make this work reliably, maybe put rj45 connectors on the weatherhead and the display module and your users could use or make a cat5/cat6 cable rather than trusting them to cut and resolder your wires like we did…

There’s no settings to adjust for the baud rate on I2C, the clock rate is on the slow end though to maximize distance.


Still working good all evening! 0 lux is dark outside now. This is so cool to watch all day.

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