http://www.solarbotics.com/cad/products/50831/
http://www.solarbotics.com/cad/products/17385/
Structural
Tubing Thichness
http://www.ptm.gs/pdfs/burstcollapse.pdf
http://www.eng-tips.com/viewthread.cfm?qid=211389&page=9
http://www.eng-tips.com/viewthread.cfm?qid=231463&page=9
http://books.google.com/books?id=LKn-oVIHXDUC&pg=SA7-PA111&lpg=SA7-
Petroleum production engineering: a computer-assisted approach
Blind Thickness
http://www.eng-tips.com/viewthread.cfm?qid=209386&page=9
http://www.swecofab.com/spectacle/designspecs.htm
Accelerometers
http://www.sparkfun.com/commerce/product_info.php?products_id=8658
http://www.st.com/stonline/products/literature/ds/12726.pdf
http://www.sparkfun.com/commerce/product_info.php?products_id=8791
http://www.sparkfun.com/datasheets/Sensors/Accelerometer/SCA3000-D01.pdf
http://www.sparkfun.com/commerce/product_info.php?products_id=8755
http://www.sensr.com/products/testing-and-development/gp1.php
http://www.sparkfun.com/commerce/product_info.php?products_id=9723
http://www.sparkfun.com/datasheets/Sensors/Accelerometer/BST-BMA180-DS000-03.pdf
FFT
http://en.pudn.com/search_db.asp?keyword=FFT+VB
http://www.youtube.com/watch?v=ObklYbQaX24
http://www.youtube.com/watch?v=vlFdVYAXIxg
http://testrf.com/2010/tutorial/spectrum-analyzer-tutorial/
http://www.radio-electronics.com/info/t_and_m/spectrum_analyser/rf-analyzer-basics-tutorial.php
http://www.spectrum-analyzer.info/Spectrum_Intro.aspx
http://www.multi-instrument.com/doc/D1002/FFT_Basics_and_Case_Study_using_Multi-Instrument_D1002.pdf
http://www.drdobbs.com/cpp/199500857
http://logix4u.net/DSP/Fast_Fourier_Transform/Visual_Basic_program_for_Fast_Fourier_Transform.html
http://sharp.bu.edu/~slehar/fourier/fourier.html
Public Sub fft()
pi = 3.14159265
1000 'THE FAST FOURIER TRANSFORM
1010 'Upon entry, N% contains the number of points in the DFT, REX[ ] and
1020 'IMX[ ] contain the real and imaginary parts of the input. Upon return,
1030 'REX[ ] and IMX[ ] contain the DFT output. All signals run from 0 to N%-1.
1060 NM1% = N% - 1
1070 ND2% = N% / 2
1080 M% = CInt(Log(N%) / Log(2))
1090 J% = ND2%
1100 '
1110 For i% = 1 To N% - 2 'Bit reversal sorting
1120 If i% >= J% Then GoTo 1190
1130 TR = REX(J%)
1140 TI = IMX(J%)
1150 REX(J%) = REX(i%)
1160 IMX(J%) = IMX(i%)
1170 REX(i%) = TR
1180 IMX(i%) = TI
1190 K% = ND2%
1200 If K% > J% Then GoTo 1240
1210 J% = J% - K%
1220 K% = K% / 2
1230 GoTo 1200
1240 J% = J% + K%
1250 Next i%
1260 '
1270 For L% = 1 To M% 'Loop for each stage
1280 LE% = CInt(2 ^ L%)
1290 LE2% = LE% / 2
1300 UR = 1
1310 UI = 0
1320 SR = Cos(pi / LE2%) 'Calculate sine & cosine values
1330 SI = -Sin(pi / LE2%)
1340 For J% = 1 To LE2% 'Loop for each sub DFT
1350 JM1% = J% - 1
1360 For i% = JM1% To NM1% Step LE% 'Loop for each butterfly
1370 IP% = i% + LE2%
1380 TR = REX(IP%) * UR - IMX(IP%) * UI 'Butterfly calculation
1390 TI = REX(IP%) * UI + IMX(IP%) * UR
1400 REX(IP%) = REX(i%) - TR
1410 IMX(IP%) = IMX(i%) - TI
1420 REX(i%) = REX(i%) + TR
1430 IMX(i%) = IMX(i%) + TI
1440 Next i%
1450 TR = UR
1460 UR = TR * SR - UI * SI
1470 UI = TR * SI + UI * SR
1480 Next J%
1490 Next L%
1500 '
End Sub