How to Adjust LPMS-IG1 Low-Pass Filter Bandwidth

Adjustment for LPVR-DUO

By default low pass filtering is applied to LPMS-IG1 gyroscope output. This improves the quality of the signal for applications with slow rotations. In case of faster rotations e.g. in a motion simulator it is recommended to change the low-pass filter settings for the sensor to become more responsive. 

In this example, we are changing the low pass filter settings of the GyroI (high precision) gyroscope. Please follow the steps below to do this:

  1. Create a yaml file, eg. IG1_G1_LP2500.yaml, with the following content:

    1 2 3 SETTINGS: ADVANCED: 1 G1F: 2500
  2. Open LpmsControl2 and connect to LPMS-IG1

  3. Upload the created IG1_G1_LP2500.yaml settings to sensor:
    menu bar → Settings → Load settings from file > Select IG1_G1_LP2500.yaml

  4. Save settings to sensor:
    menu bar → Settings → Save parameters to sensor

  5. Power cycle. The sensor should now respond faster to orientation changes.

  6. You can save a copy of the settings to file and look for the value of G1F to confirm settings are successfully applied:

 

Generally Available Settings

In the settings file the following lines can be edited to change the filter settings for LPMS-IG1 gyroscope and accelerometer:

Key

Description

Available Values

Key

Description

Available Values

AR

Acc Range (g)

2, 4 (default), 8, 16

AOR

Acc output data rate (Hz)

3, 7, 15, 31, 62, 100 (default), 125, 200, 250, 500, 1000

AF

Acc 3-dB bandwidth (Hz)

5, 10 (default), 21, 45, 99, 218, 420

GR

Gyro range (dps)

400 (default), 1000, 2000

G1OR

GyroI (high precision) output data rate (Hz)

100, 200, 400, 800, 1600, 3200, 6400, 12800 (default)

G1F

GyroI (high precision) low pass filter settings

value of G1F is calculated as:

G1F = LpfOrder*1000 + LpfFrequency

where:

  • LpfOrder (low pass filter order): 2, 3, 4 (default)

  • LpfFrequency (low pass filter cutoff frequency, Hz): 10 (default), 35, 45, 50, 70, 85, 100, 140, 175, 200, 285, 345, 400, 500

  • Default value: 4*1000 + 10 = 4010

G2OR

GyroII (high range) output data rate

3, 7, 15, 31, 62, 100 (default), 125, 200, 250, 500, 1000

G2F

GyroII (high range) 3-db bandwidth (Hz)

5, 10 (default), 20, 41, 92, 176

IMPORTANT: Please make sure AOR and G2OR settings are the same. This is because the accelerometer and gyroscope II belongs to the same chip and share the same data output rate. In case of different values, G2OR value will be used to set the chip data output rate. Please note that the parameters will be erased and revert to default values if a factory reset is performed.

NOTE: These extended settings are usually not required for optimum LPVR-DUO performance.

Default settings:

1 2 3 4 5 6 7 8 9 10 SETTINGS: ADVANCED: 1 AR: 4 AOR: 100 AF: 10 GR: 400 G1OR: 12800 G1F: 4010 G2OR: 100 G2F: 10