©2010 Skookum Robotics, Ltd
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Servo Output Layouts:
Power Bus:
For helis with blades longer than 500mm, we strongly recommend you use the
optional SK-PW7 power bus. This accessory isolates the SK720 from vibration
carried by heavier servo cables and is capable of handling 20 amps of continuous
current to eliminate brownouts.
Misc Outputs:
If it’s difficult to see the SK720’s status LED when it’s mounted on the
helicopter, you can use an external LED on an extension wire. Just connect it to
the port labelled “EX-LED” like a normal servo cable. For this port, the top pin is
for Green, the middle pin is for Red, and the bottom pin is Ground. Note that this
option cannot be used in combination with a traditional radio receiver.
There are also two additional ports on the side and back of the SK720 gyro. One
is for connecting the SK-LCD interface and the other is a GPS port. The GPS
port allows for optional expansion accessories to be connected.
©2010 Skookum Robotics, Ltd
16
9
Modes, Indicators, and Power-Up
The two primary modes are Setup mode and Flight mode. The SK720 will
automatically switch to setup mode whenever it is connected to a PC by a USB
cable or connected to an SK-LCD Terminal.
While the SK720 is in setup mode, it will do the control mixing for the helicopter
but it will not provide any stabilizing action. This enables mechanical setup and
servo trimming. While in this mode, the indicator LED will slowly flash green.
In Flight mode, the LED Indicator will show solid red while the SK720 initializes
and will turn solid green once the SK720 is ready to fly. The SK720 will also
pump the swashplate once after it initializes properly.
The gyro will not finish initializing until it is allowed to stand completely still for
several seconds. An uninitialized SK720 will be able to fly but the helicopter
might not be in trim. Always verify that the LED indicator is showing solid green
before taking off to avoid flying in an out of trim condition.
LED State
Meaning
Slow Green
Setup Mode
Fast Green
USB File Transfer
Solid Red
Flight Mode - Initializing
Solid Green
Flight Mode – Ready to Fly
Green, with Red Flicker
Flight Mode – High Vibration Warning
Flashing Red
Error State
Alternating Red / Green
Firmware Updating – Do Not Disturb
A rapidly flashing red LED indicator indicates an error. There are four possible
causes:
1)
The cyclic stick wasn’t centered during gyro initialization in flight mode
2)
The supply voltage fell below 3.6v at some point
3)
It is too hot or too cold
4)
The gyro has a systems fault
If the first three causes can be ruled out, please contact technical support.
NOTE:
The setup software will display the error state that resulted in the
flashing red LED in the
Live Data
area. Connect the gyro to the setup software
using the USB cable to determine the specific type of error. Error states are also
recorded in the log file and will be displayed by the 3D viewer during playback.
Resetting the gyro will clear the error state.
