Accelerometer FXLS896xAF - bug in library ?

[adde_ado]

Hi,

I'm testing the FXLS8964AF sensor on our custom board and I'm not getting any interrupts on INT1 when I configure my sensor for shake detection.

In a struct named gFxls896xafShakeConfig I have found the following comment but FXLS896xAF_INT_PIN_SEL_SDCD_OT_INT2_DIS is equal to 0x00. Is this a bug or have I missed something?

/* SDCD_WT_ENenabled for INT2 */

Our BT_MODE pin is connected to GND and my intention is to use  INT1 as our interrupt pin.

This is our register configuration (pretty much the same as it is explained in AN12004 on page 12):

Register      Data

0x15            0x00

0x15            0x02               FSR = 4 g and Standby mode

0x17            0x33               Wake ODR = 400 Hz and Sleep ODR = 400 Hz

0x2F            0x20               Enable X axis only for SDCD OT function

0x30            0xF0

0x31            0x04               Debounce time = 4 × (1/400) = 10 ms

0x33            0xFE

0x34            0xFA

0x35            0x02 

0x36            0x05

0x20            0xA0             Enabling DRDY_EN and SDCD_OT_EN

0x21            0x00              Routing DRDY interrupt to INT1 pin

0x15            0x03              FSR = 4 g and ACTIVE = 1

Best regards,

Adde

[AmitPurohit · Accepted solution]

Thanks Tomas.

Hi Adde,

FXLS896xAF_INT_PIN_SEL_SDCD_OT_INT2_DIS set to 0x00 configures INT1 pin for routing SDCD OT interrupt.

You can try following sensor configuration for shake detection:

Register Name	Offset	Value (to write)	Description
SENS_CONFIG1	0x15	0x02	FSR = +/-4g and Standby mode
SENS_CONFIG3	0x17	0x33	Wake ODR=400 Hz and Sleep ODR = 400 Hz
SENS_CONFIG4	0x18	0x21	Enable SDCD outside of thresholds event Auto-WAKE/SLEEP transition source enable and INT polarity set to high
SDCD_CONFIG1	0x2F	0x20	Enabling SDCD OT for X-axis
SDCD_CONFIG2	0x30	0xF0	Enable SDCD function, Enable Absolute Reference Mode and set OT Debounce counter to clear immediately when threshold criteria is false
SDCD_OT_DBCNT	0x31	0x04	Debounce time = 4 for transient detection
SDCD_LTHS_LSB	0x33	0xFF	Registers 33h and 34h set the OT LOWER threshold. In this example it is set to hex2dec (FAFE) × 1.95 mg/LSB = -2.5 g.
SDCD_LTHS_MSB	0x34	0xFA
SDCD_UTHS_LSB	0x35	0x02	Registers 35h and 36h set the OT UPPER threshold. In this case it is set to hex2dec (0502) × 1.95mg/LSB = +2.5 g
SDCD_UTHS_MSB	0x36	0x05
ASLP_COUNT_LSB	0x1E	0xFF	Registers 1Eh and 1Fh enable the ASLP function and set the sleep mode transition timer. In this example it is set to hex2dec (07D0) × 2.5 ms (400 Hz Wake ODR) = 5 sec
ASLP_COUNT_MSB	0x1F	0x08
INT_EN	0x20	0x01	Enabling WAKE_OUT_EN
INT_PIN_SEL	0x21	0x00	Routing WAKE_OUT_EN interrupt to INT1 pin
SENS_CONFIG1	0x15	0x03	FSR = +/-4 g and ACTIVE = 1

Please try suggested sensor configuration.

Regards,

Amit Purohit.

[TomasVaverka]

+ @AmitPurohit - can you please look into it and comment?

Thanks & Regards,

Tomas