The NXP Precision 9DoF breakout has the following pinout:
- VIN - 3.3-5V input, which feeds the on board 3.3V voltage regulator and optionally sets the signal levels for the I2C pins (SCL and SDA) if you are using a 5V system. On a 3.3V system (any Adafruit Feather, for example), connect 3.3V to VIN for 3.3V logic throughout the system. On a 5.0V system, connect VIN to 5V, and the signals will be shifted downward to 3.3V before reaching the NXP sensors (which are limited to 3.6V or less for the pins).
- 3Vo - This is the output of the 3.3V linear regulator on the NXP Precision 9DoF Breakout. On a 5V system, you can use this as an additional 3.3V supply if you need some extra 3.3V power.
- GND - This should be connected to GND on your development board.
- SCL - I2C, Connect this to SCL on your development board. This pin is level-shifted and 3-5V logic safe.
- SDA - I2C, Connect this to SDA on your development board. This pin is level-shifted and 3-5V logic safe.
- RST - Optionally connect this to RST on your development board (depending on the logic level used), or to a GPIO pin if you wish to manually reset the sensors on the breakout. This pin isn't required in most circumstances, but can be useful to recover from error conditions on long running systems where the sensors might have entered an unknown config state. This pin is level-shifted and 3-5V logic safe.
- AI1, AI2 - This two pins allow interrupts from the Accelerometer/Magnetometer (see the datasheet for details). These are not level shifted but since they are outputs only, you can use with 3 or 5V logic systems.
- GI1, G12 - These two pins allow interrupts from the Gyroscope (see the datasheet for details). These are not level shifted but since they are outputs only, you can use with 3 or 5V logic systems.
Since 9DoF sensors are usually used for orientation and detecting movement, you'll normally want to securely connect the breakout to something before using it.
The pinout below shows how you can connect the NXP Precision 9DoF Breakout to any Adafruit Feather development board. The image below uses the Bluefruit nRF52 Feather, which is a great MCU to combine with the NXP Precision 9DoF since the ARM Cortex M4F has a lot of processing power, and Bluetooth Low Energy makes it easy to get the orientation data onto your phone or computer without any cables getting in the way!