Gwyscope is a low cost Digital Signal Processor (DSP) suitable for Scanning Probe Microscopy measurements, focusing on demonstrating the concept of adaptive  scanning, general XYZ data acquisition and statistical data processing on the controller level.

It is based on a low cost FPGA board Red Pitaya and additional high bit depth AD and DA converters. When put together with the AFM scanning hardware (sensor, scanner and their amplifiers) and user interface software it can serve as a standalone SPM system. Otherwise, it can serve as a sub-module for a custom built SPM system, e.g. providing the feedback loop mechanism only. Finally, it can be used as a board for developing advanced sampling techniques, which was the primary goal of  the development.

Using Gwyscope as a microscope DSP, the following scanning concepts can be demonstrated:

  • scanning using non-regular scan paths from the Libgwyscan library
  • generating XYZ data and further processing them in Gwyddion open source software
  • performing statistical analysis of surface parameters at controller level, handling properly the roughness or periodic structures
  • developing self-controlled scanning regimes using Lua scripts
  • using client-server SPM controller approach based on Gwyfile library.

The core of the DSP is running as a server on Zynq processor on the Red Pitaya board. Additional AD and DA converters are attached to this board and a dedicated library is setup to control both these converters and high speed functionality implemented on the FPGA. The server used this library to control the experiment, based on the commands received from client, connected via Ethernet. The client can be anything starting from simple script up to complex graphical user interface. The server can run individual commands (start/stop feedback, set velocity, etc.), run scanning along some path or run Lua scripts. This provides large variety of potential control schemes for scanning.

Gwyscope development was supported by project FV40238 in program TRIO funded by the Ministry of Industry and Trade of the Czech Republic and by the project 20IND08 MetExSPM that received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.

Do you like Gwyscope? If yes, please cite our article in HardwareX: Scanning Probe Microscopy controller with advanced sampling support.