I2C Temperature Probe

[ADWSystems]

Is there such a thing as a I2C bus temperature probe? I have been using DS18B20 based probes in development, but with a few design changes it would make it much simpler and cheaper if the probe was I2C based. The searches I have done have resulted in a few SMT chips, but nothing in a pre-made probe nor anything I could figure out how to mount in a thermowell and make the probe myself.

Anyone know of any manufacturers or sources for an I2C based temperature probe?

 

[JonSea]

I have used the TI TMP512/TMP513 power monitor chips as temperature sensors (and also as a thermocouple signal conditioner), which is an I2C chip. It's available in a small QFN package, so a probe could be made.

But the reason you can't find a prebuilt probe is probably that I2C isn't designed to work over any great distance; it's usually used to communicate between chips on a board.

The Dallas 1-wire protocol is designed for long distance remote communications.

 

[ADWSystems]

I only need to go 2-3 meters. Some of the data I have found says I'll be fine, other data says maybe not.

In the end I need to build a simple "module" with remote discrete I/O (8 of each would be plenty as I'm already using PCF8575 chips) and temperature, using as few chips as possible. Right now the count is 3 chips and 4 relays.

 

[JonSea]

The TMP512/TMP513 can use 2 or 3 diodes or transistors as remote temperature sensors. These signsls may be more amenable to cable runs of a few meters than I2C if they meet accuracy/resolution requirements.