Power Pins:

  • Vin - this is the power pin. Since the sensor chip uses 3 VDC, we have included a voltage regulator on board that will take 3-5VDC and safely convert it down. 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
  • 3Vo - this is the 3.3V output from the voltage regulator, you can grab up to 100mA from this if you like
  • GND - common ground for power and logic

I2C Logic Pins

  • SCL - I2C clock pin, connect to your microcontroller's I2C clock line. This pin is level shifted so you can use 3-5V logic, and there's a 10K pullup on this pin.
  • SDA - I2C data pin, connect to your microcontroller's I2C data line. This pin is level shifted so you can use 3-5V logic, and there's a 10K pullup on this pin.
  • STEMMA QT - These connectors allow you to make I2C connections to dev boards with STEMMA QT connectors or to other things with various associated accessories

SPI Logic pins:

Because the HTS221 is only capable of 3-pin SPI, take care when reading the pin descriptions below and consult the wiring diagram on the Arduino page

All pins going into the breakout have level shifting circuitry to make them 3-5V logic level safe. Use whatever logic level is on Vin!

  • SCL - This is the SPI Clock pin, its an input to the chip
  • SDA - For 3-pin SPI, this pin does double duty and is connected to your device's MISO and MOSI pins:
    • MISO - Connect directly to the HTS221's SDA pin
    • MOSI - Connect to SDA through a 1K resistor
  • CS - this is the Chip Select pin, drop it low to start an SPI transaction. Its an input to the chip

If you want to connect multiple HTS221's to one microcontroller, have them share the SCL and SDA pins. Then assign each one a unique CS pin.

Other Pins

  • DRDY - Data ready pin. The HTS221 can be configured to change the state of this pin to signify that new pressure or temperature measurements are available

This guide was first published on Mar 17, 2020. It was last updated on Mar 17, 2020.

This page (Pinouts) was last updated on Apr 13, 2021.

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