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Notes dumping place for possible Arduino speed-log
ALL DEPENDS on proven functionality of the speed transducer- first things first, remove transducer and test...
- Planned platform is Arduino NANO with Serial LCD.
- Arduino Mini is cheaper by %50 apparently…
- Important is display type- black on white is best for sunlight conditions. Backlight also required. Maybe white on blue would work well in sunlight?
- Important is character support- LARGE NUMBERS are necessary.
Basic Functional description
- X Buttons for functions Y
- Calibration mode, 1 nautical mile, 1/2 nautical mile
- For now it seems that traveling 1 mile and counting the number of transducer clicks will provide an adequate average result
- Once the number of clicks for 1 n. mile is found, math is Distance in n. mile divided by time in hours = Speed in knots, choose a very small unit of time to count clicks for to allow fast updates of speed calculation (2s?)
Best I can get this described in ASCII:
D = distance in nautical miles
T = time in hours
S = speed in knots
D/T = S
X = Number of clicks counted while traveling a calibration mile
Y = Number of clicks counted in a single sample period
Z = Sample period in Seconds
D = Y/X * 1 n.m.
T = Z/3600
So: (Y/X * 1 n.m.) / (Z/3600) = Speed in knots for the sample period Z
E.G. If we calibrate 1 n.m. at 2500 clicks (X=2500) and our sample/update period is 2 seconds (Z=2), and over that period we count 10 clicks (Y=10), then calculated speed would be (10/2500)/(2/3600) = S = 0.004 / 0.0006 = 6.67 knots.
LCD Links, in order of viability
http://store.seetron.com/bpp420l-4x20-serial-lcd-with-led-bac420420.html
http://www.seetron.com/bpp440_1.htm - $140
http://www.seetron.com/bpp420_1.htm - not black on white, $59, $12 bezel kit - large numbers with punctuation
http://www.seetron.com/pdf/bpp423.pdf
→ http://www.matrixorbital.com/lk20425gw-p-11.html - blue on white, $89 for extended temp (-20C - +70C) and 9-15v range, large numbers - could be good. manual here: http://www.matrixorbital.ca/manuals/LK_series/LK204-25/LK204-25.pdf
http://www.matrixorbital.com/lcd-character-lcds-c-1_2.html
http://www.matrixorbital.com/lcd2041gw-p-71.html - black on white, $69, includes large numbers
http://www.matrixorbital.ca/manuals/LK_series/LK204-25/view?searchterm=None
http://moderndevice.com/LCD.shtml
More expensive, but viable: http://www.crystalfontz.com/products/index-ser.html
Some decent info: http://reefprojects.com/wiki/Main_Page
Sparkfun has some interesting displays, this one isn't serial, but nice looking and cheap: http://www.sparkfun.com/commerce/product_info.php?products_id=710
