Why is my INT1 of LIS2DW always at high?

Allen Lin · ‎2018-01-25

Posted on January 25, 2018 at 18:52

Hi,

My problem is I can not receive the interrupt signal of INT1 when I using FIFO mode with FIFO buffer full trigger. I find the cause is that the INT1 is always at high, but I expect it should be rise high when FIFO buffer is full.

My HW is

http://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mems-motion-sensor-eval-boards/steval-mki179v1.html

(

LIS2DW12TR), I using the following pins for I2C

SCL, SDA, VDD, GND, SA0 (connect to

GND)

My Pin configuration for INT1 on MCU side is

PIN_GPIO_LOW | PIN_PUSHPULL| PIN_IRQ_POSEDGE

SW startup sequence:

if(LIS2DW12_getRegisterValue(LIS2DW12_WHO_AM_I_ADDR) == LIS2DW12_WHO_AM_I_DEF)

{

LIS2DW12_setRegisterValue(

LIS2DW12_CTRL2_ADDR

, LIS2DW12_BDU_MASK | (commProtocol << 4)); // set BDU on and CS_PUDISC

LIS2DW12_setRegisterValue(

LIS2DW12_CTRL4_INT1_PAD_ADDR

, LIS2DW12_INT1_FIFO_FULL_MASK); //triger PIN INT1 when FIFO buffer is full

LIS2DW12_setRegisterValue(

LIS2DW12_CTRL6_ADDR

, LIS2DW12_FS_CODE(fullScaleCode)); //set full scale code

LIS2DW12_setRegisterValue(

LIS2DW12_FIFO_CTRL_ADDR

, LIS2DW12_FIFO_MODE(LIS2DW12_FIFO_FIFO) | LIS2DW12_SAMPLES(FIFOBuffSize-1)); //set FIFO mode and FIFO buffer size

LIS2DW12_setRegisterValue(

LIS2DW12_CTRL7_ADDR

, LIS2DW12_CTRL7_INTERRUPTS_ENABLE_MASK); //enable the interrupts

LIS2DW12_setRegisterValue(

LIS2DW12_CTRL1_ADDR

, LIS2DW12_ODR_SELECTION(LIS2DW12_bandWithCode) | LIS2DW12_POWER_MODE(LIS2DW12_powerMode));

}

The above setting of register is showing on following table. The yellow mark label is 1.

I also read the registers after setting

LIS2DW12_CTRL1_ADDR

and the result is :

0x18 (00011000) = LIS2DW12_getRegisterValue(LIS2DW12_CTRL2_ADDR);

0x04

(00000100)

= LIS2DW12_getRegisterValue(LIS2DW12_CTRL4_INT1_PAD_ADDR);

0x30

(00110000)

= LIS2DW12_getRegisterValue(LIS2DW12_CTRL6_ADDR);

0x3F

(00111111)

= LIS2DW12_getRegisterValue(LIS2DW12_FIFO_CTRL_ADDR);

0x10 (00010000)= LIS2DW12_getRegisterValue(LIS2DW12_CTRL7_ADDR);

0x24

(00100100)

= LIS2DW12_getRegisterValue(LIS2DW12_CTRL1_ADDR);

I also test the INT1 status. The INT1 of MCU is low if I don't connect it to

http://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mems-motion-sensor-eval-boards/steval-mki179v1.html

, but it will always be high after I connect it to

http://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mems-motion-sensor-eval-boards/steval-mki179v1.html

.

Please help me to check my configuration of registers and startup sequence.

Thank you for your helping.

Best Regards,

Allen

#fifo-buffer-interrupt #fifo-buffer #lis2dw12 #lis2dw

Miroslav BATEK · ‎2018-01-26

Posted on January 26, 2018 at 18:19

I checked you configuration and it seems to be correct.

In my case the interrupt goes high if the FIFO is full, and it is cleared if read a sample from FIFO or turn off the FIFO.

Can you please try to turn off the FIFO FIFO_CTRL (0x2E) = 0x00 and check the state of INT1 pin?

Are you sure you configured the interrupt in in the microcontroller as input?