LSM6DSL - inemo inertial module: always-on 3D accelerometer and 3D gyroscope. Milano, October 19 th -20 th 2016

Transcription

1 LSM6DSL - inemo inertial module: always-on 3D accelerometer and 3D gyroscope Milano, October 19 th -20 th 2016

2 XL/Gyro filtering chain Embedded digital features: Free-fall Wake-up 6D/4D orientation detection Single-tap and double-tap sensing Activity/Inactivity recognition Summary 2 Embedded Android functions: Pedometer functions (step counter and step detector) Significant Motion detection Relative Tilt Mode 2: Sensor Hub mode FIFO

3 XL Filtering Chain 3 Free-fall LOW_PASS_ON_6D Analog Anti-aliasing LP Filter ADC Digital LP Filter LPF1 ODR/2* ODR_XL[3:0] * The cut-off value of this LPF1 output is ODR/2 when the XL is in HP mode. It s equal to 740Hz in LP/NM mode ODR/4** Smart functions 0 1 LPF1_BW_SEL 0 1 Digital LP Filter LPF2 HPCF_XL[1:0] Digital HP Filter SLOPE_FDS 1 0 LPF2_XL_EN 0 1 HPCF_XL[1:0] Wake-up Activity / Inactivity 0 1 HP_SLOPE_XL_EN 0 6D / 4D FIFO SPI/ I 2 C ** The cut-off value of this LPF1 output is always ODR/4 (in both HP mode and LP/NM mode) INPUT_COMPOSITE HPCF_XL[1:0] SLOPE FILTER 00 1 S/D Tap

4 Slope Filter 4 ACCELERATION acc(t n-1 ) acc(t n ) SLOPE Slope(t n ) = [ acc(t n ) - acc(t n-1 ) ] / 2

5 Gyroscope Filtering Chain 5 Analog Anti-aliasing LP Filter ADC Digital HP Filter HP_EN_G 0 1 Digital LP Filter LPF1 LPF1_SEL_G 0 1 Digital LP Filter LPF2 ODR_G[3:0] FIFO SPI/I 2 C FTYPE[1:0]

6 Recognize when the device is in free-fall Configurable parameters: FF Threshold FF Duration Free-fall detection 6 Z FF Duration Y + FF Threshold 0g FREE- FALL ZONE X - FF Threshold FF Interrupt

7 Wake-up 7 Recognize when the device is moved Configurable parameters: WK Threshold WK Duration ACCELERATION acc(t n ) acc(t n-1 ) SLOPE WK Duration Slope(t n ) = [ acc(t n ) - acc(t n-1 ) ] / 2 + WK Threshold - WK Threshold WK Interrupt

8 6D/4D orientation detection 8 Detect the orientation of the device in space, enabling easy implementation of energy-saving procedures and automatic image rotation for mobile devices Configurable parameters: Z Y Z Y 6D Threshold (50, 60, 70, 80 ) 6D/4D detection mode X X (a) (b) Z Y Z Y X X (c) (d) Z Z Y Y X X (e) (f)

9 Single-tap and double-tap sensing 9 Generate interrupt signal when the device is single/double tapped in any direction (recommended XL ODR >= 400Hz) Configurable parameters: Tap Threshold Shock time Quiet time (Double tap) Duration time (Double tap) Slope + Tap Threshold - Tap Threshold (a) SHOCK QUIET SHOCK QUIET SINGLE TAP Interrupt SHOCK SHOCK (b) QUIET DURATION QUIET DOUBLE TAP Interrupt

10 Activity/Inactivity recognition 10 Automatically decrease the accelerometer sampling rate to 12.5 Hz, increasing the accelerometer ODR and bandwidth as soon as the wake-up interrupt event has been detected Configurable parameters: WK Threshold Slope Sleep Duration WK Duration + WK Threshold - WK Threshold SLEEP_DUR WAKE_DUR Interrupt INACTIVITY STATUS ACTIVITY STATUS

11 t Pedometer functions: Step counter & Step detector A specific IP block dedicated to pedometer functions: the step detector and the step counter. Pedometer functions work at 26 Hz (XL only) 11 Configurable parameters: Number of debounce steps Debounce restart time Pedo Full-scale (2g / 4g) Minimum Threshold Amplitude Actual THS Minimum THS Detected step

12 Significant Motion Detection 12 The Significant Motion function generates an interrupt when a significant motion, that could be due to a change in user location, is detected. Significant Motion function works at 26 Hz (XL only) Configurable parameters: Number of steps to be performed before an SMD interrupt is generated

13 Relative Tilt 13 The Tilt function allows detecting when an activity change occurs (e.g. when phone is in a front pocket and the user goes from sitting to standing or standing to sitting). Tilt algo works at 26Hz (XL only) First Tilt interrupt: tilt angle > 35 for a period of time >= 2 sec Next Tilt interrupts: as soon as tilt angle > 35 (no need to wait 2 sec) START POSITION #0 FINAL POSITION #0 START POSITION #1 35º 35º 35º 35º TILT DETECTION INTERRUPT

14 Mode 2 - Sensor Hub mode (1/2) 14 In Sensor Hub mode (Mode 2) up to 4 external sensors can be connected to the I2C master interface External sensor data can also be stored in FIFO Magnetometer hard-iron / soft-iron correction External pull-up is optional LSM6DSL Vdd_IO Ext Sensor R 1.5 kohm I2C / SPI to HOST SDx Vdd_IO R 1.5 kohm SDA SCx SCL INT2 Data Ready I2C MASTER External trigger is optional I2C SLAVE

15 Mode 2 - Sensor Hub mode (2/2) 15 I2C interface pass-through mode MCU Vdd_IO LSM6DSL Vdd_IO Ext Sensor SDA R Vdd_IO 10 kohm SDA SDx R Vdd_IO 1.5 kohm SDA SCL R 10 kohm SCL SCx R 1.5 kohm SCL PASS_THROUGH_MODE bit INT2

16 FIFO (1/2) 16 LSM6DSL embeds an 4 kbyte first-in first-out buffer (FIFO) allowing to limit intervention by the host processor and facilitate post-processing data for event recognition The FIFO can be configured to store the following data: Gyroscope sensor data Accelerometer sensor data External sensors (connected to sensor hub interface) data Step counter and timestamp data Temperature sensor data Five different FIFO operating modes: Bypass mode (FIFO disabled) FIFO mode Continuous mode Continuous-to-FIFO mode Bypass-to-Continuous mode

17 FIFO (2/2) 17 All data sets can be stored in FIFO at different ODRs, by setting the decimation factors FIFO status signals: FIFO overrun events FIFO full status FIFO empty status FIFO threshold status Number of unread samples stored in the FIFO Stop on watermark High part of data only mode

18 Thank You! 18