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| The impeller mounted on the front of the trike, for testing and rough calibration. |
We found that pitot tubes, even those used for model airplanes, don't have enough resolution and accuracy at the speeds we will be flying (16 to 19 kph, or 10 to 18 mph). Therefore, we are using an impeller type
Tony had previously got the Arduino reading a hall effect sensor with the magnet, and he got the bluetooth working and RPMs displaying on an android tablet. On Tuesday and Wednesday we got the magnets glued to several impellers (props from large rubber band powered model planes), and we mounted one to the trike and rode around and compared the output to the speed from a cyclometer on the trike, and got it roughly calibrated.
Fine calibration will require test runs in nil wind, probably in the next week or two, whether and time depending.
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| Our raw materials (rubber flying models) |
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| Test impellers with magnets, waiting to get final trimming and coating of epoxy to hold magnets firm |
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| Closeup of Hall Effect sensor mounted near magnet on prop |
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| Extension cable going back to Arduino |
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| Arduino mounted on Trike |
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| The entire setup in place on Trike |
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| Jocelyn testing the airspeed sensor |
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| Testing can be fun! |
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| Andy doing some laid-back testing |
Video of airspeed sensor testing
A Pitot like aispeed measurement can be used. Of course a non common differential pressure sensor should be used. I've put an 8 mm pitot on a bike http://www.basicairdata.eu/attachments/blog/images/pitotbike.jpg. The basic design is that reported in http://www.basicairdata.eu/instruments.html . Compliments for your project!
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