Digital control of force microscope cantilevers using a field programmable gate array

Details Digital control of force microscope cantilevers using a field programmable gate array Digital control of force microscope cantilevers using a field programmable gate array

2008-09-08

arxiv.org/abs/0809.1403v1

Rev.Sci.Instrum.79:123705,2008

Physics

Instrumentation and Detectors

submitted to Review of Scientific Instruments

Scientific paper

10.1063/1.3043432

This report describes a cantilever controller for magnetic resonance force microscopy (MRFM) based on a field programmable gate array (FPGA), along with the hardware and software used to integrate the controller into an experiment. The controller is assembled from a low-cost commercially available software defined radio (SDR) device and libraries of open-source software. The controller includes a digital filter comprising two cascaded second-order sections ("biquads"), which together can implement transfer functions for optimal cantilever controllers. An appendix in this report shows how to calculate filter coefficients for an optimal controller from measured cantilever characteristics. The controller also includes an input multiplexer and adder used in calibration protocols. Filter coefficients and multiplexer settings can be set and adjusted by control software while an experiment is running. The input is sampled at 64 MHz; the sampling frequency in the filters can be divided down under software control to achieve a good match with filter characterisics. Data reported here were sampled at 500 kHz, chosen for acoustic cantilevers with resonant frequencies near 8 kHz. Inputs are digitized with 12 bits resolution, outputs with 14 bits. The experiment software is organized as a client and server to make it easy to adapt the controller to different experiments. The server encapusulates the details of controller hardware organization, connection technology, filter architecture, and number representation. The same server could be used in any experiment, while a different client encodes the particulars of each experiment.

Affiliated with

Also associated with

No associations

Rating

Digital control of force microscope cantilevers using a field programmable gate array does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Digital control of force microscope cantilevers using a field programmable gate array, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Digital control of force microscope cantilevers using a field programmable gate array will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-31182