Filter is a key part for solar chromospheric telescopes. The core of its control system is a high-precision temperature control system. Traditional filter temperature control mode controls the average temperature by switching the heating wire. Such a control mode can not be used for space filters because it consumes a larger power supply.

Depending on the space-based solar observatory being studied in China, space filter with automatic wavelength stabilization is being researched and the project intends to work out a method, so as to fit the circumstance in space and to automatically adjust the position through wavelength according to the subtle changes in ambient temperature.

Considering the limit for space electronics, this paper describes the design of filter controller based on Field Programmable Gate Array(FPGA) and single chip microcomputer (SCM), which has stronger data processing ability for control algorithm and can be used to receive c1ontrol commands and upload status. FPGA is used to build multiple communication ports, step motor control Intellectual Property (IP) cores and expand input and output interfaces.

The controller can also be used in other telescopes, astronomical instruments and industrial control systems as well.