Power Pins

The sensor on the breakout requires between a 2.7V and 5.5V, and can be easily used with most microcontrollers from an Arduino to a Feather or something else.

  • Vcc - this is the power pin.  To power the board, give it the same power as the logic level of your microcontroller - e.g. for a 5V micro like Arduino, use 5V
  • GND - common ground for power and logic

I2C Logic Pins

  • SCL - this is the I2C clock pin, connect to your microcontroller's I2C clock line.
  • SDA - this is the I2C data pin, connect to your microcontroller's I2C data line
  • STEMMA QT - These connectors allow you to connectors to dev boards with STEMMA QT connectors or to other things with various associated accessories

Other Pins

  • INT -This is the interrupt pin. You can setup the PCT2075 to activate this pin when a temperature threshold is reached or exceeded.
  • A0, A1, A2 - I2C Address pins. See the "I2C Address Selection" section below

I2C Address Selection

One of the improvements that the CPT2075 has over the LM75 that it can replace is the ability to have three times the number of I2C addresses. Interestingly, they achieve this by allowing the three address pins A0, A1, and A2 be in one of three states, low (0), high(1), or floating(F). This means that the are 33 (27) possible addresses. Attach the address pin to ground for low, the logic level of your device for hight, or leave the pin unconnected for floating.

We leave all three address pins floating on the breakout for maximum configurability. This means that the default address for the breakout is 0x37.

For a more permanent address selection, you can use the solder jumpers on the back of the breakout board to connect the address pins to GND or VCC.

All you need to do is bridge the "Float" pad to either the VCC or GND pad for one or more of the address pins. In the picture above if you bridged the solder pads that are circled, you would pull A0 high to VCC and A1 low to GND. Referring to the table above this would set the address of the breakout to 0x27

This guide was first published on Sep 25, 2019. It was last updated on Sep 25, 2019.
This page (Pinouts) was last updated on Oct 20, 2020.