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 microcontroller 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 connectors to dev boards with STEMMA QT connectors or to other things with various associated accessories

SPI Logic pins:

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 also the SPI Clock pin, it's an input to the chip
• SDA - this is also the Serial Data In / Microcontroller Out Sensor In pin, for data sent from your processor to the LIS2MDL
• SDO - this is the Serial Data Out / Microcontroller In Sensor Out pin, for data sent from the LIS2MDL to your processor. 
• 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 LIS2MDLs to one microcontroller, have them share the SDA, SDO and SCL pins. Then assign each one a unique CS pin.