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Activity Detection Interrupt Question

Question asked by NeerajSingla on Jan 19, 2018
Latest reply on Jan 22, 2018 by NeerajSingla

Hi jwang,

 

I am seeing an interesting behavior with the Activity Detection interrupt. If I use the below mentioned configuration, then the interrupt is never generated. I tried tapping the device and slamming it on a table with different forces, but the interrupt was never generated.

Whereas if i change the Power Control Register setting from 0x03 to 0xB0, then i can get the interrupt. Writing 0B on PWR_CNTRL will disable the low pass filter, but with a bandwidth of 1600Hz i think we should have been able to get activity interrupt.

 

txByteCounter = 0;

config[txByteCounter++]= (0x23<<1);  // 0x23 = THRESH_ACT_X_H

config[txByteCounter++]= 0b00000110;
config[txByteCounter++]= 0b01000001;
config[txByteCounter++]= 0b00000110;
config[txByteCounter++]= 0b01000001;
config[txByteCounter++]= 0b00000110;
config[txByteCounter++]= 0b01000001;

for (i = 0; i < 15; i++)
{
config[txByteCounter] = 0;
txByteCounter++;
}
config[txByteCounter++] = 0x03; // HPF
config[txByteCounter++] = m_fifoEntriesCount; // FIFO Samples
config[txByteCounter++] = 0b00000010; // FIFO CTL
config[txByteCounter++] = 0b00100000; // INT1 Map
config[txByteCounter++] = 0; // INT2 Map
config[txByteCounter++] = 0b01100000; // EXTERNAL Timing Control
config[txByteCounter++] = 0b00001011; // Measurement Control
config[txByteCounter++] = 0x03; // Power Control

 

Thanks,

Neeraj

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