Eagle Tree Systems Airspeed MicroSensor V3 Instruction Manual

Instruction Manual for the Airspeed MicroSensor V3

Document Version 1.1

Thank you for your purchase! This instruction manual will guide you through the installation and operation of your Airspeed MicroSensor
V3 (the MicroSensor). Please read the entire manual carefully before proceeding. If, after you read the manual, you have further
questions or problems, see the Support page on http://www.eagletreesystems.com for additional information, or email us at

[e-mail]. Please visit our support web page for the full color, electronic version of this manual which may be

updated if changes were made after printing, or if you want to view the manual on your computer.

What the MicroSensor Does

The MicroSensor is a precision instrument that uses a Prandtl style pitot-static tube to measure airspeed, just as full sized planes do.
Advanced temperature compensation and calibration ensure the best possible accuracy. When used standalone, the MicroSensor displays
your maximum speed on the built-in 7 segment LED display. Additionally, the MicroSensor can be connected to your eLogger (any
version) to provide airspeed data for your entire flight. When connected to the eLogger, airspeed can be displayed and graphed using the
eLogger’s Windows software.

IMPORTANT: It is extremely unlikely that the installation of the MicroSensor will affect your model’s radio range or control. But, as
always after making an electronics change to your model, it is very important that you range and function test your model once the
MicroSensor is installed to ensure that there is no impact on your system.

Packing List

Your package should include the following: The MicroSensor, a machined brass and aluminum Prandtl style pitot-static tube, the Standalone
Cable, two lengths of approximately 3 foot (1 meter) small diameter silicon hose, and a printed version of this manual. NOTE: Additional
Pitot Tube kits are available for purchase on our website, for use with multiple models.

Installing the Pitot Tube and MicroSensor in your Model

Using two lengths of the included small diameter silicon tube, the pressure and static connections of the pitot tube connect to the “+” and “-”
ports of the MicroSensor, respectively, as shown in Figure 1. It is best to mount the pitot tube in your model first, then determine where
you will mount the MicroSensor, and then cut the two lengths of silicon tube so they reach between the two.

Follow these guidelines when mounting the pitot tube:

1. The pickup end of the pitot tube (the silver colored tip) should be pointing toward the direction of the model’s travel. While best results
will be obtained if the pitot tube is perfectly aligned with the direction of travel in both axes, the “Prandtl” design of the tube will
compensate somewhat for higher angles of attack.

2. The static holes on the pitot
tube (shown on Figure 1)
should extend at least 1/2”
(13mm) past the wing’s
leading edge, or past any other
obstructions - the farther out,
the better. This is to ensure
that the static holes and pitot
pickup are in undisturbed air.

3. For prop planes, it’s important
that the tube be placed so that
it is not directly in the plane’s
prop-wash, which will result in
erroneous readings. The best
place to install the tube is on
the leading edge of the wing

Copyright © 2008 Eagle Tree Systems, LLC
http://www.eagletreesystems.com

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several inches out from the fuselage, as shown in Figure 1.

4. For jets, gliders, or “pusher” prop planes, the nose cone often provides a perfect mounting location.

After Pitot Tube installation, it is recommended that you glue or otherwise attach the silicon hose to the airframe, to reduce the chance that
hose vibration or movement could cause erroneous readings.

The MicroSensor circuit board can be mounted anywhere in the model. If you wish to read the LED without removing the wing, a small
rectangular hole can be cut at the mounting location of the circuit board, and the board mounted with tape or Velcro, so that the LED is
visible at all times.

Using the MicroSensor in Standalone Mode

Powering the MicroSensor in Standalone Mode

For standalone mode (not connected to an eLogger), connect
the Standalone Cable to the gold pins of the MicroSensor, as
shown in Figure 2. Note that the RED wire of the standalone
cable corresponds with the red dot on the label.

The JR/Universal servo end of the Standalone Cable connects
to a spare Receiver channel or small battery. Note that the
voltage must be between 3V and 16V. Do not exceed 16V!

IMPORTANT: Ensure that you connect the Standalone
Cable with the correct polarity, or the MicroSensor could
be damaged, voiding the warranty!

Note that in Standalone Mode, the 4 wire cable built into
the MicroSensor must NOT be connected to anything!

Configuring Metric vs English Units in Standalone Mode

When powered on, the LED readout will briefly display “0” if the unit is configured for English (MPH), or will display a “1” if configured
for metric (KPH). The factory default configuration is MPH.

To switch between English and metric units, connect the
Standalone Cable as described above, but don’t power the
MicroSensor. Then, connect a small piece of wire between the
unconnected pins of the Standalone Cable’s 4 pin connector,
corresponding to the brown and yellow dots on the label, as
shown in Figure 3. This creates a jumper between the brown
and yellow labeled pins.

Then, power the MicroSensor via the Standalone Cable. A “0”
will then flash a few times to indicate that English units are
configured, or a “1” will flash if Metric units are configured. If
the wrong units are configured, just disconnect the power from the MicroSensor and reconnect it.

Once the desired units are configured, disconnect from power and remove the wire jumper. Then, when reconnected to power, the desired
units should be displayed briefly (“0” or “1”).

Reading Airspeed in Standalone Mode

When the MicroSensor is powered on, after the Units setting is displayed (“0” or “1”), the highest speed attained during your last flight is
repeatedly displayed, one digit at a time, on the LED. For example, if the highest speed attained was 120MPH, “1 – 2 – 0” will flash
repeatedly on the LED, with a pause (blank LED) after the speed is completely displayed, but before it is displayed again.

After landing from your next flight, the highest speed attained during that flight is displayed automatically, overwriting the highest speed
from your prior flight. Note that a speed of at least 9 MPH (15 KPH) must be attained before a new highest speed is displayed.

Copyright © 2008 Eagle Tree Systems, LLC
http://www.eagletreesystems.com