I'm running a series of tests on the ADIS16210. Using the Datalogger function of the ADIS16210 evaluation software I am outputting the values of all three ACCL & INCL registers. My understanding is that the values in the INCL registers are computed using the values in the ACCL registers.
I have seen two equations in regards to this computation. One is shown on page 12 of the data sheet using the "atan2" function and an unknown constant Kgp. The other is discussed in the app note AN-1057 using a simple "atan" function with no constant. Using the data from the ACCL registers, I computed the angles using both methods.(I used the value of 1.00 for Kgp). Both methods gave the same answer, although the "atan2" function needed a quadrant shift to match the "atan" function. While the computed angle values were very close to the angles outputted in the INCL registers, they did vary by as much as .005 degrees. Any insight as to why this happens. Is there more to the computation of the INCL angles than just these equations? Thanks.