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LIS2DH12 Double Click Interrupt

Question asked by Veerappan.Chithambar on Jan 4, 2017
Latest reply on Jan 10, 2017 by Veerappan.Chithambar

Hi All

 

I am having some difficulties in configuring the Double Click Interrupt on the LIS2DH12.

 

After power up, I am doing the following:

 

TEMP_CFG_REG = 0xC0

CTRL_REG4 = 0x80

CTRL_REG1 = 0x77

 

The above seems to work and provides sensible values for xyz axis when the PCB is at various angles. This suggests that the I2C bus is functioning correctly. 

 

Next I would like to enable click detection in the y- axis (any axis would do to start to prove the function works). I would like an interrupt on INT1 when a double click has occurred. INT1 is pulled up to 3.3 V via a 100 kOhm resistor.

 

I am doing the following in order to configure the Double Click feature

 

CTRL_REG3 = 0x80

CLICK_CFG = 0x08

CLICK_THS = 0x88

TIME_LIMIT = 0xFF  //Not really sure the purpose of this, the datasheet is not really clear

TIME_LATENCY = 0xFF  //Not really sure the purpose of this, the datasheet is not really clear

TIME_WINDOW = 0xFF  //Not really sure the purpose of this, the datasheet is not really clear

 

All other registers are left at their default values. 

 

I am then reading the CLICK_SRC register in a loop. I am checking to see if bit 6 is a 1, which indicates that an interrupt has occurred.

 

Looking at the INT1 pin on the scope, it appears to be toggling. I understand that the INT1 will switch after CKICK_SRC is read, however the value read back indicates that no double (or single) click interrupt has occurred. Looking at the datasheet I also thought that all the other interrupts were disabled by default. 

 

If anyone has any suggestions or thoughts or even a working basic configuration, it would be much appreciated.

 

Thank you

 

Kind regards

 

Chithambaram 

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