AnsweredAssumed Answered

ADXL345 Activity interrupts not triggering

Question asked by reidkersey on Jun 6, 2017
Latest reply on Jun 19, 2017 by Anthony.DeSimone

I am new to using the ADXL345. I just was able to get communication going to it, but I am unable to trigger an activity or inactivity interrupt. I have tried shaking it, leaving it be, and everything in between. I have I2C communication setup with the chip. I can get data from the DATAx0 & 1 registers, but it seems a bit off. Below is my configuration of the chip.


Write to 0x1E - 0x00

Write to 0x1F - 0x00

Write to 0x20 - 0x00

Write to 0x21 - 0x00

Write to 0x22 - 0x00

Write to 0x23 - 0x00

Write to 0x25 - 0x02

Write to 0x26 - 0x00

Write to 0x2A - 0x00

Write to 0x2C - 0x1A

Write to 0x2D - 0x38

Write to 0x2E - 0x18

Write to 0x2F - 0x18

Write to 0x31 - 0x04

Write to 0x38 - 0x4F



When I read the registers for X, Y, and Z, I get the following:

0x32 0xC0

0x33 0x05

0x34 0x80

0x35 0x03

0x36 0x80

0x37 0xBF


The device is nearly flat on my desk with the accelerometer facing down. When I put my phone in approximately the same position I get:

X: .1

Y: .1

Z: -.99


Why are the interrupts not triggering, and does the Data for X, Y, Z make sense? How do I interpret the X, Y, Z data?


I have attached the capture from my Saleae logic analyzer. It can be read with the Saleae Logic Software.