I believe Ken is competing in Pittsburgh this weekend, so you may not hear from him as often as usual (but I bet he'll find time to get on-line).
You will need to take the ADXRS150 40 Hz sample rate into account when calculating your heading. Depending on how you've setup your gyro sampling for the old gyro, you'll need to scale each gyro sample to average the over-sampling.
If you are using a timer to specify the gyro sample rate in the fast loop, for instance, and you are taking 100 samples per second then you might have the line:
Code:
gyro_sum += gyro_sample * 40 / 100;
Are you are flat-out sampling the gyro every time through the fast loop?