Abstract:The airborne altimeter which used magnetoelectric pointer indicator has lots of defects ,such as low reading accuracy, poor seismic performance, poor non-linearity and difficult to store analog data. If airborne altimeter indicator adopt digital display, not only the height data can be read easily and the reading accuracy be improved, but also the height data can be stored in the computer data processing system and can be used in conjunction with other operations, thus improving the overall performance of the equipment. In view of this problem, according to height voltage signal characteristics of airborne altimeter, a circuit of altimeter display used single-chip microcomputer and interface circuit is presented. By means of interface circuit, function expansion and software programming, the analog height voltage of the airborne altimeter is sampled, quantized, A/D converted, nonlinear corrected and LED digital display is performed. Practice results show that the digital display circuit has lots advantages, such as high precision, easy storage, low manufacturing cost, strong versatility, only need to modify the digital display meter check procedures can be applied to other altimeter magnetoelectric digital display; the analog signal is a typical processing.