The Adafruit PCT2075 Temperature Sensor is a 'code compatible' drop in replacement for a very common I2C temperature sensor, the LM75. Compared to the LM75, however, the 11-bit ADC in the PCT2075 provides more precise measurements when compared to the LM75's 9-bit ADC. Additionally because the PCT2075 allows the address pins to work in three states (high, low, floating), you can have 27 PCT2075s on the same bus as opposed to only 8 for the LM75. Now you can finally measure the individual temperatures of the tentacles of three octopuses instead of just one!

Otherwise the two sensors are the same. The PCT2075 will report temperature and allow you to a set a high temperature threshold that the sensor will compare to the current temperature and raise an alert when the current temperature exceeds the threshold. There are also a few (metaphorical) knobs to twist to change the alerting and measurement behavior.

As with all Adafruit breakouts, we've done the work to make this handy temperature helper super easy to use. We've put it on a breakout board with the required support circuitry and connectors to make it easy to work with, and is now a trend we've added SparkFun Qwiic compatible STEMMA QT JST SH connectors that allow you to get going without needing to solder. Just use a STEMMA QT adapter cable, plug it into your favorite micro or Blinka supported SBC and you're ready to rock!

The PCT2075 is a handy and inexpensive temperature sensor that does one thing well. Try adding one to your project and have it keep an eye on the temperature and let you know when things get hot - or cold!

We have a full tutorial with schematics, pinouts, libraries, datasheets, Fritzing objects and more all in the Learning Guide!