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ADXL362 sensitivity problem

Question asked by robertjenkins on Jan 22, 2018
Latest reply on Jan 23, 2018 by jwang

Hello I am having difficulty with the ADXL362 sensitivity. (I am using this with the ATTINY84 which makes it hard to debug - no serial output)

 

The device is set to go into wake-up mode after a certain period, and then, when shaken, wake up again via a pin change interrupt. But it wakes up too easily, with only slight movement - or sometimes not at all. 

 

Here is the relevant code: 

 

SPIwriteTwoRegisters(0x20, 2000);//2000 is the threshhold
SPIwriteOneRegister(0x22, 100); //100 is the time

//Set the ACT_INACT_CTL bit 1
SPIwriteOneRegister(0x27, 0x03);

// Map awake status to interrupt 1
SPIwriteOneRegister(0x2A, 0x90);
SPIwriteOneRegister(0x2D, 0x0A);

 

then later 

 

ISR(PCINT1_vect) { //Pin change interrupt
byte temp = SPIreadOneRegister(0x0B);

SPIreadOneRegister(0x0B); //clears ADXL interrupt

}

 

 

I can reduce the values for 0x20 and 0x22 to make it very sensitive indeed, but I cannot make it less sensitive. What can I do? Any help appreciated, since I am not experienced, and stuck. 

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