Continuously Updating Plot?

[csjoiner]

Hi. I'm a graduate student at UCLA developing a scanning tunnelling microscope (a microscope that can see atomic-level resolution) that will eventually be donated to over a dozen Los Angeles area high schools.

One key element of microscope operation is the need to view a continuously updating 3D plot of the surface that is being scanned while fine adjustments are made to the various manual controls until the scanning tip is properly adjusted to give a good image.

Currently, we are using LabView to generate signals and read in the data, but this is less than desirable due to the fact that LabView is very slow (this reduces the resolution of the image, as oxidation of the metal atoms on the tip of the scanning probe occurs faster than a scan can be completed, and so the apparent height of the surface being imaged "drifts" as the probe scans over the surface). Additionally, the cost of LabView software/hardware currently comprises over 60% of the cost of the entire microscope.

As such, we are generating a new program that will read data in and out through the serial port. From a graphing standpoint, the program continuously generates data points with X, Y, and Z coordinates. After finishing one scan over the surface, the program will overwrite these data points as it re-scans over the surface. Ideally, we would like a graphical program that can read these coordinates in dynamically and generate a false-color plot in real time (ie: viewing the X & Y coordinates down along the Z axis with the height, Z, at each X, Y coordinate represented by varying shade of color) however, any continuously-updating 3D representation of the surface would be useful!

Is this possible with DPlot or DPlot Jr.? Any suggestions would help!

Thanks!
Steve

[DPlotAdmin]

Steve,
It's possible, but whether it is practical or not will largely depend on how many data points you're talking about and what sort of update frequency you want. I'd suggest downloading DPlot Jr and running, for example, the ctest2.exe demo. This will give you an idea of how long it takes to produce a plot for a given number of random data points. That demo produces a 2D plot, but you can easily change it to 3D.

I'll have limited internet access over the next several days but will try to answer any of your questions on this as soon as possible.