The design of magnetoresistive compass of micro air vehicle（MAV）based on DSP is presented

which consists of S/R circuit

3D magnetic sensors

signal processing circuit and DSP.In order to achieve the highest resolution

set/reset pulse circuits is designed.It can be used to eliminate the effects of past magnetic effects and temperature drift.The error sources of this magnetoresistive compass are analysed.A non-linear

two-step error model and compensation algorithm is presented.The algorithm can be applied to any two or three-axis sensor set with an error model consisting of scale

offset

and non-orthogonality errors.The experiments show that this compass’s error is less than 1.2°.And it has many merits such as small volume

light weight

low power consumption

and high reliability etc.