Failed to enable interrupt mode

[CHEN Rene]

Posted on February 07, 2018 at 14:53

Hi,

I am working on some motion detection product.

LIS2HH12 is chosen as the motion detector. We want to use it in interrupt mode.

Unfortunately, we failed to get any signal on INT1 pin, observing by an o

scilloscope

. What a shame T_T.

My configuration sequence is as follow, could you please help to give some advice?

// startup checking SPI bus

GSENSOR::LIS2HH_set_mode: WHO_AM_I = 41 [spi]

// reset the chip

GSENSOR::LIS2HH_set_mode: RESET

// read  regs to check reset status

GSENSOR::LIS2HH_set_mode: STATUS = FF [spi]

GSENSOR::LIS2HH_set_mode: CTRL5 = 00 [spi]

// setup

GSENSOR::LIS2HH_set_mode: CTRL1 = 3F [spi]

GSENSOR::LIS2HH_set_mode: CTRL2 = 00 [spi]

GSENSOR::LIS2HH_set_mode: CTRL3 = 09 [spi]

GSENSOR::LIS2HH_set_mode: CTRL4 = 04 [spi]

GSENSOR::LIS2HH_set_mode: CTRL5 = 00 [spi]

GSENSOR::LIS2HH_set_mode: CTRL7 = 0C [spi]

// check

GSENSOR::LIS2HH_set_mode: STATUS = FF [spi]

GSENSOR::LIS2HH_set_mode: INT_SRC1 = 25 [spi]

GSENSOR::LIS2HH_set_mode: INT_SRC2 = 00 [spi]

GSENSOR::LIS2HH_set_mode: STATUS = FF

GSENSOR::LIS2HH_set_mode: val[0] = -437, x = -26.657000 mg

GSENSOR::LIS2HH_set_mode: val[1] = -169, y = -10.309000 mg

GSENSOR::LIS2HH_set_mode: val[2] = -16427, z = -1002.047000 mg♯♯

#interrupt-driven #lis2hh12

[Miroslav BATEK]

Posted on February 16, 2018 at 11:32

Comments to you configuration:

- GSENSOR::LIS2HH_set_mode: CTRL3 = 09 [spi] ... enables Interrupt generator 1 and DRDY on pin INT1 (not good to mix the two signals)

- GSENSOR::LIS2HH_set_mode: CTRL7 = 0C [spi] ... enables Interrupt generator 1 and FIFO empty in INT2 (why ???)

- Missing interrupt generator configuration IG_CFG1, IG_THS_X1, IG_THS_Y1, IG_THS_Z1, IG_DUR1

So I recommend to start with following configuration:

CTRL1 = 0x3F // 100Hz, X,Y,Z enable, BDU enable

CTRL2 = 0x02 // High pass filter enabled for Interrupt generator 1. To detect a motion only change in acceleration is needed.

CTRL3 = 0x08 // Enable interrupt generator in INT1

CTRL4 = 0x04

CTRL5 = 0x00

CTRL7 = 0x00

IG_CFG1 = 0x2A // Interrupt condition X or Y or Z is above threshold

IG_THS_X1 = IG_THS_Y1 = IG_THS_Z1 = 0x0D // Set the threshold to 100mg (adjust according to you needs)

IG_DUR1 = 0x0A // Set duration to 100ms (adjust according to you needs)