Posted on April 13, 2018 at 14:16
Hello,
I am trying to compare LIS3DH and LSM9DS1 (accelerometer part) and I am suprised by the result:
The LIS3DH has the configuration: CTRL1: 0x67 (ODR = 200Hz, LPen=0, ) CTRL4: 0xA8 (BDU, 8g, HR)
=> sampling frequency = 200Hz and BW=ODR/9=22Hz
The LSM9DS1 has the configuration: CTRL5:0x38 (no decimation), CTRL6: 0x98 (ODR = 238Hz, 8g, bandwidth determined by ODR, ) CTRL7: 0x80 (HR, filsters bypassed) CTRL8: 0x44 (BDU, IF_ADD_INC)
=> sampling frequency = 238Hz and BW=105Hz
But when I capture data with both PCBAs tightly attached, the LIS3DH signals have more amplitude and seems to have a higher bandwith.
Did I missed something or is there a problem?
Do you suggest another configuration for the LSM9DS1?
time in sec.
Best regards
Mich
1 ACCEPTED SOLUTION
Accepted Solutions
Posted on April 16, 2018 at 14:23
The reduced BW of the LSM9DS1 is cause by the HR (high-resolution) mode.
If you enable the HR mode the LP filter is added in the signal chain. You can configure the cutoff frequency using DCF bits. By default the cutoff frequency is ODR/50 so in your case 4.76Hz.
You can set the DCF [1:0] bits to 10, the cutoff frequency will be 26Hz and the results should be similar to LIS3DH.
Posted on April 16, 2018 at 14:23
The reduced BW of the LSM9DS1 is cause by the HR (high-resolution) mode.
If you enable the HR mode the LP filter is added in the signal chain. You can configure the cutoff frequency using DCF bits. By default the cutoff frequency is ODR/50 so in your case 4.76Hz.
You can set the DCF [1:0] bits to 10, the cutoff frequency will be 26Hz and the results should be similar to LIS3DH.
