- Vin - this is the power pin. Since the 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
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!
- SCK - This is the SPI Clock pin, its an input to the chip
- SDO - this is the Serial Data Out / Microcontroller In Sensor Out pin, for data sent from the BMP183 to your processor
- SDI - this is the Serial Data In / Microcontroller Out Sensor In pin, for data sent from your processor to the BMP183
- CS - this is the Chip Select pin, drop it low to start an SPI transaction. Its an input to the chip