# Adafruit PCT2075 Temperature Sensor ## Overview ![](https://cdn-learn.adafruit.com/assets/assets/000/081/413/medium800/adafruit_products_4369-05.jpg?1569432198) The PCT2075 by NXP is a pin 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. ![](https://cdn-learn.adafruit.com/assets/assets/000/081/412/medium800/adafruit_products_angle_crop.png?1569432151) 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](https://www.sparkfun.com/qwiic) compatible [**STEMMA QT**](https://learn.adafruit.com/introducing-adafruit-stemma-qt) JST SH connectors that allow you to get going  **without needing to solder.**  Just use a [STEMMA QT adapter cable](https://www.adafruit.com/product/4209), plug it into your favorite micro or Blinka supported SBC and you're ready to rock! "OK" you say "connections are one thing but how do I tell it what to do?" (Not much of a) Surprise! We've written libraries for Arduino and CircuitPython with examples that make it super easy to integrate the PCT2075 with your project. ![](https://cdn-learn.adafruit.com/assets/assets/000/081/414/medium800/adafruit_products_stemma_con_crop.png?1569432286) 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. - [Next Page](https://learn.adafruit.com/adafruit-pct2075-temperature-sensor/pinouts.md) ## Primary Products ### Adafruit PCT2075 Temperature Sensor - STEMMA QT / Qwiic [Adafruit PCT2075 Temperature Sensor - STEMMA QT / Qwiic](https://www.adafruit.com/product/4369) 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... In Stock [Buy Now](https://www.adafruit.com/product/4369) [Related Guides to the Product](https://learn.adafruit.com/products/4369/guides) ### Breadboard Friendly I2C Temperature Sensor - TC74A0 [Breadboard Friendly I2C Temperature Sensor - TC74A0](https://www.adafruit.com/product/4375) It's rare to see breadboard friendly I2C sensors, but this TO-220 package with 5 pins is, in fact, such a thing! It's a basic temperature sensor, not the highest precision in the world, only ±2°C but it will get the job done when you need simple temperature logging or... In Stock [Buy Now](https://www.adafruit.com/product/4375) [Related Guides to the Product](https://learn.adafruit.com/products/4375/guides) ## Featured Products ### STEMMA QT / Qwiic JST SH 4-pin to Premium Male Headers Cable [STEMMA QT / Qwiic JST SH 4-pin to Premium Male Headers Cable](https://www.adafruit.com/product/4209) This 4-wire cable is a little over 150mm / 6" long and fitted with JST-SH female 4-pin connectors on one end and premium Dupont male headers on the other. Compared with the chunkier JST-PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert... In Stock [Buy Now](https://www.adafruit.com/product/4209) [Related Guides to the Product](https://learn.adafruit.com/products/4209/guides) ### STEMMA QT / Qwiic JST SH 4-pin Cable - 100mm Long [STEMMA QT / Qwiic JST SH 4-pin Cable - 100mm Long](https://www.adafruit.com/product/4210) This 4-wire cable is a little over 100mm / 4" long and fitted with JST-SH female 4-pin connectors on both ends. Compared with the chunkier JST-PH these are 1mm pitch instead of 2mm, but still have a nice latching feel, while being easy to insert and remove. 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