Filters

The information on this page refers to firmware v2.43e and higher. The filters described got removed with firmware v2.67e.

The STorM32 provides a rich filter section to filter the gyro, accelerometer, encoder, and motor control data, using notch/band-cut filters.

Concept and Overview

The filters are organized into three identical filter banks, which are processed in series. That is, the data are feed into filter bank #1, the output of this bank is then feed into filter bank #2, and finally the output of bank #2 is feed into filter bank #3. This allows for a very flexible choice of filter arrangements.

The parameters of the filter banks are exemplarily described for filter bank #1. They are:

• Filter1 Source: Selects the filter source.
• Filter1 Center Frequency: Selects the center or cut-off frequency of the filter.
• Filter1 Bandwidth: Selects the bandwidth for notch or band-cut filters.
• Filter1 Attenuation: Selects the attenuation of the band-cut filters. “inf” results in a notch filter.

Filter Sources

Currently, the following data sources are available:

“off”	The filter bank is inactive.
“gyro1 all”	The raw data of gyro1 are filtered.
“gyro1 x”	The raw data of gyro1's x channel are filtered.
“gyro1 y”	The raw data of gyro1's y channel are filtered.
“gyro1 z”	The raw data of gyro1's z channel are filtered.
“imu1 all”
“imu1 x”
“imu1 y”
“imu1 z”
“mot all”	not yet implemented
“mot pitch”	not yet implemented
“mot roll”	not yet implemented
“mot yaw”	not yet implemented