User's Manual

Error! No text of specified style in document. ST application note template
8/22 Version 0.1 STMicroelectronics Confidential
DRAFT
2 Hardware description
This section describes the main components present on the board and described in
Figure 3 and 4.
2.1 Microcontroller
STM32L151VEY6 is an ultra-low-power microcontroller unit based on ARM Cortex M3. It
features a great range of low power modes and an efficient voltage scaling that allows
power saving.
2.2 Sensors
Thanks to their overall integration level the embedded sensors offer great flexibility in terms
of accuracy of the system and in terms of power consumption.
The integrated sensors perfectly fit the needs of an accurate AHRS algorithm (e.g.
embedded iNEMO-Engine running on the STM32L151VEY6), height estimation and
everything needed for wearable motion tracking: from extreme low power activity tracker to
more advanced motion reconstruction.
2.2.1 LSM6DS3
The LSM6DS3 is a system-in-package featuring a 3D digital accelerometer and a 3D digital
gyroscope performing at 1.25 mA (up to 1.6 kHz ODR) in high performance mode and
enabling always-on low-power features for an optimal motion experience for the consumer.
Up to 8 Kbyte of FIFO with dynamic allocation of significant data (i.e. external sensors, time
stamp, etc) allows the overall power saving of the system.. ST’s family of MEMS sensor
modules leverages the robust and mature manufacturing processes already used for the
production of micro machined accelerometers and gyroscopes. The various sensing
elements are manufactured using specialized micromachining processes, while the IC
interfaces are developed using CMOS technology that allows the design of a dedicated
circuit which is trimmed to better match the characteristics of the sensing element. The
LSM6DS3 has a full-scale acceleration range of ±2/±4/±8/±16 g and an angular rate range
of ±125/±245/±500/±1000/±2000 dps. High robustness to mechanical shock makes the
LSM6DS3 the preferred choice of system designers for the creation and manufacturing of
reliable products. The LSM6DS3 is available in a plastic land grid array (LGA) package.
2.2.2 LISM3DL
The LIS3MDL is an ultra-low-power high performance three-axis magnetic sensor. The
LIS3MDL has user-selectable full scales of ±4/ ±8/ ±12/±16 gauss. The self-test capability
allows the user to check the functioning of the sensor in the final application. The device
may be configured to generate interrupt signals for magnetic field detection. The LIS3MDL
includes an I2C serial bus interface that supports standard and fast mode (100 kHz and
400 kHz) and SPI serial standard interface. The LIS3MDL is available in a small thin plastic
land grid array package (LGA) and is guaranteed to operate over an extended temperature
range of -40 °C to +85 °C.