These are Windows 95/98/NT4/2000 freeware for non-commercial use. Bug reports are welcome.
Sound Card data acquisition freeware
Sound card data acquisition software: 16 bits sound, unless otherwise mentioned. Windows NT4 / 2000/XP, win95/98.
a) fftscope (If your sound card supports it, here is the 24 bits version.)
fftscope replaces function generators and FFT analyzers/oscilloscopes. Some of the things you can do are: 1) find timings: like reflections of a sound pulse to determine speed of sound 2) determine frequencies: like the rotation of a propeller with a mic. 3) frequency response and phase shift: like that of an RLC circuit or an amplifier.
Some sound cards take the R channel data slightly after the L channel. You can play with p6 (see Help in fftscope) until you get a flat phase angle plot when you do a fft-stereo scan on a white noise signal fed to both R/L channels simultaneously.
FFTW 2.1.3 library from MIT is used. That forces GNU GPL license on the source code of fftscope. Email me if you want the source code.
Bug fixes:
10/16/2007 Since someone asked, I relaxed the frequency limit for use with faster soundcards. Because the program does not check the soundcard's capability, you have to be careful when changing the sampling rate...
4/2/2007 Fix a cursor coordinate display problem in fft mode caused by last bug fix... Oh, well... No one told me...
3/1/2005 Other minor L/R delayed display problems.
10/23/2003 A bug that caused the display to shift by 1 resolution point is now fixed.
8/2/2002 The display routine is changed so that it won't waste time plotting points more than the resolution of the display. This is particularly important when you try to print 20 sec worth of data on a slow printer. It's 1 min now vs. hours before.
12/24/2002: I finally fixed the L/R delay related display problems.
The stand alone function generator that plays sine/sweeping sine/square/triangle/pulse/white noise waves.
c) Beats
This program generates two sine waves of different frequencies from the L and R channels. You will hear beats, even when you use earphones. You ears sense phase differences!!!
This program makes sine waves. But the R/L channel’s phase difference can be assigned. At low frequencies, you can demonstrate how noise can be reduced by an anti-phase noise (active noise control). At high frequencies, you can do the usual interference experiment at different angles. A microphone can be used as the detector with fftscope.
Stopwatch: This is a replacement for lab stopwatches. The resolution is 0.01 sec. There is also a function that measures reaction times. 100 most recent records are kept. Download it here.
Nucleus PCAII: I have only windows 2000 driver for this. But it should also work with windows xp
a) Portio device driver for windows 2000: You need this to run pcaII.exe
An NTDDK driver sample that does port input/output. I suppose it's OK to let people download it since NTDDK is free for download from MS anyway. Many DOS data acquisition programs can be converted into windows programs with the help of this driver. Also download the Genport.inf file and install the driver from “add hardware” in the control panel. The INF file assigns the I/O at 1E0. You can change it to where your PCAII board is. The same driver exists in all other platforms in MS DDK samples. Install the corresponding driver and you will be able to use PCAII.exe in other W32 platforms (NT4/95/98/ME).
b) pcaII.exe
It has only the most basic functions. Start/stop taking data, print, and copy the data to the clipboard for other data analysis softwares like origin or excel. Data display updates each second, until it is stopped or the preset time is reached. Click and drag will zoom in. Double click or use the menu View/reset range to zoom out. Note that data is always reset when you start taking data. The program requires no installation. Just copy and run.
Plot: plot.exe
This is a convenient plotting program that compares multiple 2-columns text data files. If the first number in the data file is –1, the second number is interpreted as a common division (normalization) factor for the rest of the y (2nd column) data. You can drag and drop data files into it or type in the file name and add it to the list in the file list menu. Click and drag to zoom-in. Double click to reload and reset to the full scale. The program shows r-factors comparisons between the first data file and others in the list. It’s a good tool when you have to compare simulations to experimental data.