compass reading

[zhlearnaq]

hello
Anyboby here? another problem please.
Recently, i was confused by compass, since the scale of hmc5983 read from datasheet is 6600 Guass/LSB, however the value used in autoquad is 187.88, what does this value mean? How to get it? And why it is different from the datasheet?

[aBUGSworstnightmare]

[zhlearnaq]

hello
Thank you for your reply. Maybe i didn't explain what i want to ask exactly, Now i will describe it again.
In the HMC5983 datasheet page 16, we can found that the Gain Settings at +/-2.5Gauss is 660(Guass/LSB), this is used to calculate mag value from original digital signal, however the value used in autoquad code is (1.0f/187.88f) refer to the function hmc5983SaleMag. Why the two value are different? How does the value (1.0/187.88) got?
What's more, the earth's magnetic field value is always less than 1(Guass) in different area, why the value we use is always compared with 2?
Can anybody show me the reason, Many thanks.