Minimize Gyroscope Latency

Only applicable on Pulse-40 OEM

This documentation is only applicable on the Pulse-40 OEM. Other Pulse IMU do not include this additional delay filter that can be disabled.

By default, the Pulse-40 OEM applies an additional FIR filter to reduce the relative delay between the accelerometer and gyroscope measurements.

For applications where minimum gyroscope latency is more important than accelerometer-to-gyroscope time alignment, this additional filtering stage can be disabled by configuring the firFilter without coefficients.

Latency vs. Sensor Synchronization

Disabling the additional FIR filtering minimizes gyroscope latency, but increases the relative delay between the accelerometer and gyroscope measurements.

Why Is an Additional FIR Filter Applied?

The accelerometers and gyroscopes have different native sampling and internal filtering characteristics. As a result, after the internal anti-aliasing filtering stage, the accelerometer measurements exhibit more latency than the gyroscope measurements.

To reduce this timing difference, the default configuration applies an additional FIR filter to the gyroscope data. This introduces additional gyroscope delay and brings the accelerometer and gyroscope measurements into close temporal alignment.

For more information about the complete sensor processing chain, see Data Processing & Filtering.

Minimizing Gyroscope Latency

Some applications require the lowest possible gyroscope latency and do not require accelerometer and gyroscope measurements to be closely time-aligned.

In this case, configure firFilter without FIR coefficients. This removes the additional filtering delay applied to the gyroscope and therefore minimizes its latency.

With this configuration, the measurements retain the timing characteristics resulting from their respective internal sensor and anti-aliasing filtering paths. The accelerometer therefore remains delayed relative to the gyroscope.

Configuration Trade-Off