User Manual

Copyright 2012 Eagle Tree Systems, LLC Page 4
Figure 2 – Receiver Connection Harness
Figure 3 – Providing Backup Power when all Guardian Servo Channels Used
• Micro USB port – this port accepts a “Micro B” USB cable (not included). Connection to a PC lets you update the Guardian
firmware, and also configure and tune your Guardian via your PC. Please see the PC User Interface section for more information.
• Accessory (Data) Port – this port is for future expansion, and is not used presently. Please let us know how we should use this port!
• LED Viewports – for your convenience, the status LED can be seen from both the top and side of the Guardian case. Please see the
Status LED section for more information.
The Receiver Connection Harness
Receiver Connection Harness Pinout
The lightweight receiver connection harness with labeled connectors should make it
easy for you to hook up the Guardian to your receiver.
A diagram of the harness is shown in Figure 2, for your reference. It has the
following labeled receiver connections:
• Ail – (required) Connects to your receiver’s Aileron output channel. Note that
this channel also supplies power and ground to the Guardian and the servos
connected to the Guardian.
• Elv – (required) Connects to your receiver’s Elevator output channel
• Rud – (optional) Connects to your receiver’s Rudder output channel
• Aux - (optional) Connects to your receiver’s Second Aileron or Flaperon output
channel, if needed
• Mod – (optional, recommended) The Mode/Config input connects to either a two-position or three-position switch. It allows you to
switch the Guardian mode during flight and to do radio stick configuration of the Guardian. See the Mode/Config Switch Behavior
section for more information.
• Gain – (optional) The Gain input connects to a knob (or slider) on your receiver, and lets you adjust the overall stabilizer gain during
flight. See the Stabilization “Master Gain” Control section for more information.
Receiver Connection Harness Load Capacity
When connected typically, the Aileron lead of the Guardian’s receiver connection harness takes power from your receiver, and this
powers the servos you have connected to the Guardian. The Receiver Connection Harness is easily capable of handling the power
requirements of typical analog and digital servos.
However, if the servos you have connected to the Guardian are very large, and/or have a combined current draw of greater than
5 amps, an additional power cable is required. Note that if your BEC or receiver battery is rated at 5 amps or less (the vast majority
are), a backup cable should not be needed. Note also that the Aileron lead of the harness should not be excessively warm after flying,
which could indicate that backup power is needed.
If the servos you have connected to the Guardian draw greater than 5 amps all together, there are two ways to supply additional power to
your servos, which will provide additional current carrying capability to the servos you have connected to the Guardian:
1) If you are not using all the servo output connections on your Guardian, a male to male servo wire (with the signal line cut!) can be
connected between a free servo channel on the
Guardian, and a free channel on your receiver.
2) If all the servo connections on the Guardian are being
used, a male/male/female Y cable (ET p/n CAB-Y-1
or similar) with the signal line cut can be used to
provide additional power to the servos, as shown in
Figure 3.
Receiver Requirements
Receiver Connection Requirements
The number of connections between the Guardian and your receiver depends on type and capabilities of your model, the level of Guardian
in-flight control you require, and the number of spare receiver channels you have. For very basic models, the Guardian is capable of
operating with only the Elevator input and Aileron input connected.
BEC/Receiver Battery Power Requirements
The Guardian 2D/3D Stabilizer is sensitive to deep voltage drops, which means that your BEC or receiver battery must be sufficient
to maintain a voltage of at least 3.5 volts, even under full servo load. The Guardian will shut off if the voltage drops below this
level!