First let me start by saying in my application I'm not using the API and have implemented my own driver. Everything is working properly when not using the FIFO. However we want to utilize the 6.4KHz ODR and this requires using the FIFO and prefiltered data. The problem I'm seeing is that when we choose filtered data for the FIFO (FIFO_DOWNS = 0x88) the data is correct and the GYRO_RANGE of +=2000dps (GYRO_RANGE = 0x00) works as expected (and matches the behavior when doing direct register reads instead of using the FIFO).
However when switching to prefiltered data (FIFO_DOWNS = 0x00) to get the 6.4KHz ODR the GYRO_RANGE seems to be ignored and the data behaves as if the range is +-250dps (as if GYRO_RANGE was set to 0x03) even though it's set to 0x00 (and verified by reading the register back). So instead of 16.4 LSB/dps it's behaving like 131.2 LSB/dps. This is unworkable in our application as we need the full +-2000dps scale.
Everything else behaves as expected. The ODR in the FIFO is 3.2KHz when using filtered and 6.4KHz when prefilitered as it should. It's just the GYRO_RANGE and the full-range scaling that seems to be misbehaving.
In this test case the FIFO was configured for headerless mode and only the gyro data was enabled (FIFO_CONFIG_1 = 0x80).
So to recap, the gyro data in the FIFO behaves normally if it's configured to be filtered data. However when set to be prefiltered data the scaling is incorrect and seems to be behaving like GYRO_RANGE = 0x03 (+-250dps) even though it's set to 0x00 (+-2000dps).
Any thoughts?