©2010 Skookum Robotics, Ltd
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8
Connections
The SK720 can accept control inputs over either traditional PWM signals from a
receiver’s servo outputs or directly from a satellite receiver. Either option can be
selected by using the setup software.
NOTE: The SK720 needs to receive separate aileron, elevator and pitch
inputs so set the swash-type in your TRANSMITTER to “1-servo” for all
input types and swash setups.
If you will be using a “standard” 120 swash with three servos, you will connect
them to SW-C (elevator, or center), SW-R (right) and SW-L (left). The tail servo
is connected to TAIL. An External LED may be connected to Ex-LED. The
electronic speed control (ESC) or throttle
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is connected to IO-A(T). External
power can be connected to IO-B and/or IO-C.
If your helicopter has blades 500 mm or larger, you should use the optional
SK-PW7 external power bus. See the Power Bus manual for more details on the
connections between the Power Bus and the Gyro.
Satellite Receivers:
The SK720 supports one or two satellite receivers. Either port A or port B can be
used if you are using only one satellite receiver. With the SK720’s power off,
connect satellite receivers to the ports marked “Sat A” or “Sat B” (or both if
using 2 satellite receivers) on the side of the unit. (Note: as far as we know, all
satellite receivers from the same manufacturer are identical).
Connected satellite receivers can be set to bind with a transmitter using the PC
setup software. Connect the SK720 to your computer using a USB cable and
select
Bind Sat RX’s on Power Cycle
from the Utility drop-down menu. (See
Sections 11 and 19 of this manual for detailed instructions on how to use the
setup software.) Both satellite receivers will then go into bind mode if the SK720
is unplugged from the USB and all power sources, then powered back up using a
battery or BEC.
In satellite receivers mode, the SK720 also outputs the throttle channel on
port “IO-A(T)”
, as well as up to three additional auxiliary outputs for such
things as a governor, landing gear, or light control (IO-B, IO-D, IO-E). The
endpoints and trims of these channels are adjusted in your radio.
NOTE: For safety, the throttle output is disabled while the SK720 is in setup
mode. Be sure to set the fail-safe throttle level using the setup software.
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ESC and throttle servo control are only available when using satellite receivers. Otherwise, these
devices must be connected directly to your external receiver.
©2010 Skookum Robotics, Ltd
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Powering the SK720:
The SK720 can accept power through any servo port except for the IO-D/E and
EXT-LED ports. All other ports make up a joined power bus. Just one port needs
to be connected to an external power supply. The allowed voltage range is 5v to
10v. For use with multiple voltages, consider using the SK-PW7 external power
bus.
Traditional Receivers:
It is important to turn the SK720’s satellite receiver option off using the PC setup
software before connecting a traditional stand-alone receiver.
For the inputs from the radio receiver, the connector mapping is:
Control Function
SK720 Port
Aileron
IO-A
Elevator
IO-B
Rudder
IO-C
Collective Pitch
IO-D
Gain / Bank Select
EXT-LED
Note that only one port needs to supply power to the device, so only the signal
(top) pin needs to be connected to the receiver for all others.
Also note that there is no throttle input to the SK720 from an external receiver.
The throttle signal from an external receiver must bypass the SK720 and be
connected directly to the throttle servo or BEC.
Swash Outputs:
The swash servos are connected as per the following table and diagram:
Swash Setup Type
SW-C
SW-R
SW-L
SW-A
120, 135/140 deg eCCPM
Centre
Right
Left
n/a
“1-servo” mCCPM
Elev
Aile
Pitch
n/a
90-deg eCCPM
Fwd
Right
Left
Aft
Left/Right means the heli’s left and right, looking from its tail to its nose.
