Test Setup – General
I have connected the T1000FC to a 8-channel Corona DSSS receiver. Channels 1,2,4,6 (aileron,elevator,rudder,mode). Channel 3 (throttle) from the receiver goes directly to the ESC. There is no connection to the BATT terminals on the end. Power is applied via the leads from the receiver to t he T1000FC module. Channel 6 was initially a pot on the transmitter providing full range (1000-2000 uS). The 3 gain adjustments are set to about half in the normal direction. Three 9g mini servos are used for bench testing.
I later changed channel 6 on the transmitter to a 3-position switch providing 1000, 1500 and 2000 uS. Failsafe was not set up. When the transmitter was turned off, channel 6 on the receiver stops providing a PPM signal.
The two DIP switches on the T1000FC are in the “normal wing” position (as supplied, both up).
There are 2 LEDs, red and green. The RED LED indicates initialization and operation. The green LED indicates flight mode as set by channel connected to “Auto-pilot” (RC channel 6 in my case).
There is reference to a sensor calibration operation that is initiated by setting both DIP-Switches to ON and then applying power while the T1000FC is flat/horizontal and still. The red LED flashes for about 15 seconds before returning to normal, which depends on the mode setting.
Before connecting the GPS
With the transmitter ON, the green LED follows the mode control; lo-med-hi = off-on-flashing. With the transmitter OFF the green LED flashes and stability mode is enabled. Applying power and the red LED flashes 2 times then stays on. The aileron and elevator servos move to counter T1000FC movement; ie. to hold the plane level. The rudder servo does not move with T1000FC movement. Probably because without GPS it doesn’t know if it’s going in a straight line or drifting off.
With channel 6 low (min: 1000uS) the T1000FC has no effect on the servos for fully manual control (pass-through) and the green LED is off. In the centre position (1500uS) movement of the T1000FC causes the servos to react to level the plane and the green LED is on. RC control is slow and releasing the sticks leaves the servos in a offset position. Apparently this is 3D mode. In the max position (2000uS) movement of the T1000FC also causes the servos to react to level the plane and the green LED is flashing. The red LED is always on. RC control is normal. This is stabilized normal flight.
Flight modes without GPS are:
- 1000uS – manual, pass-through, no stability
- 1500uS – 3D stability with rudder (RC slow and releasing stick leaves servo in new position – stability on rudder)
- 2000uS – stability without rudder and normal RC control (referred to as altitude/attitude)
With the GPS plugged in
A loss of GPS returns to altitude/attitude stability mode. Power on and the red LED flashes twice then a short delay before flashing. The blue LED (GPS module, see below) seems to be the only indication of a GPS fix.
Flight modes with GPS are:
- 1000uS – stability (RC on rudder only – ailerons move occasionally (RTL?) – )
- 1500uS – stability (RC on rudder and ailerons only – no stability on rudder
- 2000uS – stability (RC on rudder, ailerons and elevator – )
It seems that with the GPS connected, there is no manual or pass-through flight mode that does not include stability assistance.
There is suggestion of more than 3 flight modes when the GPS is connected; selected using the 3-position switch. These modes and GPS operation are not yet clear.
I have done another walk test with the cardboard box setup. The RTL mode did sort of make sense, but I also had some inconsistent results, suggesting there may be more flight modes controlled by the 3-position switch.
You cannot set the home position until it has a GPS fix. Hold the button for 3-5 seconds and the red LED stays on for 3 seconds then goes back to flashing, and home should be set. If it doesn’t indicate, wait a minute and try again.
When you have only rudder response from the RC, I’m 90% sure you are in RTL mode; the T1000FC is looking after ailerons and elevator.
I don’t know how it determines what height to fly at, but at ground level it sets the elevator for a bit of up.
I’m still not sure how the other flight modes work when the GPS is connected.
To date, there are some comments on the forums as to how it works, but they seem to be untested and just add confusion. I’ve only seen one report on line of anyone actually flying it, and that plane went home in a rubbish bag.
I need a small model that bounces really well for the next stage of testing.
There is a mix-up or swap between Aileron and Rudder gain adjustments.
The servos do move or twitch at times. On the bench this may be due to the GPS position drifting and the T1000FC trying to correct. This should only happen in RTL flight mode.
The Hobbyking product information mentions a barometer, which I would take to mean a pressure sensor, typically used for more accurate altitude control. But looking inside the controller, I don’t see a pressure sensor.
If there is no barometer, altitude hold would have to be GPS based. Accuracy would depend on the number of satellites available and could easily be +/- 10-20 meters out and unstable.
The supply current draw hovers around 0.13A-0.15A; including the receiver.
There is no ICSP header. It looks like the Reset pin of the Mega328 is floating, so it should be possible to use the Hobbyking adaptor to reprogram the CPU on-board.
I don’t know if it’s Arduino based but it would probably make sense if it was.
There is a blue LED bottom-left corner of the front of the GPS module. It is just visible through the plastic when shaded from light. The LED is on when powered. When it has a fix the LED pulses off at about a 1Hz rate.
The case is mostly waterproof with a soft gasket.
It is possible to remove the plastic case to reduce weight. Remove the rear sticky mounting tape to expose the 4 screws.
The T100FC must be installed facing the correct way in the model; terminals to the rear and labelled face up. As with any stability controller it must be isolated from vibration on a suitable mounting such as double sided sticky foam.
The T1000FC should be mounted so that it is level when the model is in level flight. It may be possible to calibrate out errors, but why make it more complicated or risk unreliable operation.
Hobbyking Product Information
The Turnigy T1000FC auto pilot system with GPS is an in-line flight stabilizing system that offers auto level, tilt angle limits and return to home functionality at an unbelievable value.
The T1000FC can be added to any type of aircraft supporting conventional layouts, flying wings, V-tail and A-tail airframes. Installation is as easy as unplugging your servos from your receiver and adding this in-line between the two and selecting the proper control surface direction.
There is a total of 5 flight modes selectable in the T1000FC; autopilot mode (auto levels and does not let the aircraft roll or pitch past 45 degrees), 3D mode for sport flying, Flight mode (stabilization off), Fixed high direction mode (heading hold), altitude hold mode (this will maintain the aircraft’s altitude) and GPS return to home. The various flight modes can be easily accessed from a three position switch on your transmitter.
The Turnigy T1000FC is the perfect product for FPV users with auto levelling and return to home functions and a great tool for beginners to RC flying allowing for an adjustable degree of safety and autonomy.
PRODUCT ID: 9041000164-0.
mrranganator69 on the RC Groups thread gave a very good description of the operation of the 3-position switch on a Turnigy 9XR transmitter. It went something like this:
The up position is RTH. The middle position is Alt-Hold. The bottom position is Manual (with gyros). Switching from bottom to middle, puts you in Altitude-Heading Hold mode.
Switching from up to middle, puts you in Altitude Hold mode.