Pololu LSM6DS33 3D Accelerometer and Gyro Carrier with Voltage Regulator

The LSM6DS33 combines a digital 3-axis accelerometer and 3-axis gyroscope into a single package. The sensor provides six independent acceleration and rotation rate readings whose sensitivities can be set in the ranges of ±2 g to ±16 g and ±125°/s to ±2000°/s, available through I²C and SPI interfaces. This LSM6DS33 carrier board includes a 3.3 V voltage regulator and integrated level shifters that allow operation from 2.5 to 5.5 V, and the 0.1? pin spacing makes it easy to use with standard solderless breadboards and 0.1? perfboards.

This board is a compact (0.4? × 0.9?) breakout board for ST?s LSM6DS33 inertial module, which features a 3-axis digital linear accelerometer and 3-axis digital rate gyroscope; we therefore recommend careful reading of the LSM6DS33 datasheet (1MB pdf) before using this product. The LSM6DS33 is a great IC, but its small package makes it difficult for the typical student or hobbyist to use. It also operates at voltages below 3.6 V, which can make interfacing difficult for microcontrollers operating at 5 V. This carrier board addresses these issues by incorporating additional electronics, including a 3.3 V voltage regulator and level-shifting circuits, while keeping the overall size as compact as possible. The board ships fully populated with its SMD components, including the LSM6DS33, as shown in the product picture.

The LSM6DS33 inertial measurement unit (IMU) has many configurable options, including dynamically selectable sensitivities for the accelerometer and gyro, a choice of output data rates, and two independently-programmable external inertial interrupt pins. The accelerometer and gyro can be individually turned on and off to save power. The sensor can be configured and its readings can be accessed through a digital interface, which can be configured to operate in either I²C (TWI) or SPI mode.

The six independent acceleration and angular rate readings (sometimes called 6DOF) provide data that a microcontroller or computer can use to calculate the orientation of the LSM6DS33 on two axes (roll and pitch; a magnetometer is generally required to compute yaw accurately). With an appropriate algorithm, the gyro can be used to very accurately track rotation on a short timescale, while the accelerometer can help compensate for gyro drift over time by providing an absolute frame of reference.

The carrier board includes a low-dropout linear voltage regulator that provides the 3.3 V required by the LSM6DS33, which allows the sensor to be powered from a 2.5-5.5 V supply. The regulator output is available on the VDD pin and can supply almost 150 mA to external devices. The breakout board also includes a circuit that shifts the I²C clock and data lines to the same logic voltage level as the supplied VIN, making it simple to interface the board with 5 V systems, and the board?s 0.1? pin spacing makes it easy to use with standard solderless breadboards and 0.1? perfboards.

This LSM6DS33 carrier is pin-compatible with many of our previous ST I²C/SPI sensor carriers, including our LSM303D compass and accelerometer carrier and L3GD20H gyro carrier, and the orientation of the sensor axes is the same. However, since the ICs contain different sensors with different I²C addresses and configuration registers, code written to interface with another chip will need to be modified to work with an LSM6DS33.

For sensor fusion applications, our MinIMU-9 v5 and AltIMU-10 v5 inertial measurement units combine this LIS3MDL with an LSM6DS33 3-axis accelerometer and 3-axis gyro on a single board, providing nine independent readings that can be used to calculate an absolute orientation. The AltIMU-10 v5 also includes an LPS25H pressure sensor that can be used to calculate altitude.

Specifications

• Dimensions: 0.4? × 0.9? × 0.1? (10 × 23 × 3 mm)
• Weight without header pins: 0.6 g (0.02 oz)
• Operating voltage: 2.5 V to 5.5 V
• Supply current: 2 mA
• Output format (I²C/SPI):
  • Accelerometer: one 16-bit reading per axis
  • Gyro: one 16-bit reading per axis
• Sensitivity range (configurable):
  • Accelerometer: ±2, ±4, ±8, or ±16 g
  • Gyro: ±125, ±245, ±500, ±1000, or ±2000°/s