MiniMU-9 v3 Gyro, Accelerometer, and Compass (L3GD20H and LSM303D Carrier)
The Pololu MinIMU-9 v3 is an inertial measurement unit (IMU) that packs an L3GD20H 3-axis gyro and an LSM303D 3-axis accelerometer and 3-axis magnetometer onto a tiny 0.8″ × 0.5″ board. An I²C interface accesses nine independent rotation, acceleration, and magnetic measurements that can be used to calculate the sensor’s absolute orientation. The MinIMU-9 v3 board includes a voltage regulator and a level-shifting circuit that allows 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.
The Pololu MinIMU-9 v3 is a compact (0.8″ × 0.5″) board that combines ST’s L3GD20H 3-axis gyroscope and LSM303D 3-axis accelerometer and 3-axis magnetometer to form an inertial measurement unit (IMU); we therefore recommend careful reading of the L3GD20H datasheet (3MB pdf) and LSM303D datasheet (1MB pdf) before using this product. These sensors are great ICs, but their small packages make them difficult for the typical student or hobbyist to use. They also operate at voltages below 3.6 V, which can make interfacing difficult for microcontrollers operating at 5 V. The MinIMU-9 v3 addresses these issues by incorporating additional electronics, including a voltage regulator and a level-shifting circuit, while keeping the overall size as compact as possible. The board ships fully populated with its SMD components, including the L3GD20H and LSM303D, as shown in the product picture.
Compared to the previous MinIMU-9 v2, the v3 version offers a number of improvements arising from the use of newer MEMS sensors, including a wider maximum magnetic sensing range and better gyroscopic accuracy and stability. This version also adds a pin for changing the sensor slave addresses, allowing two MinIMUs to be on the same I²C bus. The MinIMU-9 v3 is pin-compatible with the MinIMU-9 v2, but changes in I²C addresses and configuration registers might require some changes to software written for older versions (this should not be an issue if you are using our Arduino libraries).
The MinIMU-9 v3 is pin-compatible with the AltIMU-10 v4, which offers the same functionality augmented by a digital barometer that can be used to obtain pressure and altitude measurements. The AltIMU includes a second mounting hole and is 0.2″ longer than the MinIMU. Any code written for the MinIMU-9 v3 should also work with the AltIMU-10 v4.
- Dimensions: 0.8″ × 0.5″ × 0.1″ (20 mm × 13 mm × 3 mm)
- Weight without header pins: 0.7 g (0.02 oz)
- Operating voltage: 2.5 V to 5.5 V
- Supply current: 6 mA
- Output format (I²C):
- Gyro: one 16-bit reading per axis
- Accelerometer: one 16-bit reading per axis
- Magnetometer: one 16-bit reading per axis
- Sensitivity range:
- Gyro: ±245, ±500, or ±2000°/s
- Accelerometer: ±2, ±4, ±6, ±8, or ±16 g
- Magnetometer: ±2, ±4, ±8, or ±12 gauss
|SCL||Level-shifted I²C clock line: HIGH is VIN, LOW is 0 V|
|SDA||Level-shifted I²C data line: HIGH is VIN, LOW is 0 V|
|GND||The ground (0 V) connection for your power supply. Your I²C control source must also share a common ground with this board.|
|VIN||This is the main 2.5 V to 5.5 V power supply connection. The SCL and SDA level shifters pull the I²C bus high bits up to this level.|
|VDD||3.3 V regulator output or low-voltage logic power supply, depending on VIN. When VIN is supplied and greater than 3.3 V, VDD is a regulated 3.3 V output that can supply up to approximately 150 mA to external components. Alternatively, when interfacing with a 2.5 V to 3.3 V system, VIN can be left disconnected and power can be supplied directly to VDD.|
|SA0||3.3V-logic-level input to determine I²C slave addresses of the three ICs (see below). It is pulled high by default through 10 kΩ resistor. This pin is not level-shifted and is not 5V-tolerant.|
The CS, DEN, data ready, and interrupt pins of the L3GD20H and LSM303D are not accessible on the MinIMU-9 v3. In particular, lack of the CS pin means that the optional SPI interface of these ICs is not available. If you want these features, consider using our L3GD20H carrier and LSM303D carrier boards.
|Size:||0.8″ × 0.5″ × 0.1″1|
|Minimum operating voltage:||2.5 V|
|Maximum operating voltage:||5.5 V|
|Axes:||pitch (x), roll (y), and yaw (z)|
|Measurement range:||±245, ±500, or ±2000°/s (gyro)
±2, ±4, ±6, ±8, or ±16 g (accelerometer)
±2, ±4, ±8, or ±12 gauss (magnetometer)2
|Supply current:||6 mA|