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Posted by kallend | Feb 28, 2014 @ 08:08 PM | 9,929 Views
I have LED strips on my F550 with NAZA M. The attached spm file uses the DX9 sequencer to produce a strobe-like effect with the LEDs. The sequencer produces the "flash" effect and the mixer adds this to the selected output channel (AUX3 in my case). The mixer also adds in a value from one of the 3-way switches (I used switch D), so that the overall result is, depending on the switch position, that the LEDS are "off", "strobe", or "on".

The Rx AUX3 output drives the LEDs through an electronic on-off switch such as this http://hobbyking.com/hobbyking/store...ed_Switch.html

You may need to reverse the channel output depending on whether switch you use is active low or active high.

Edited to add: Whatever channel you choose to drive the lights needs to be assigned to INH in Channel Assign, so that the sequencer or switch can then be used to drive that channel using the MIXER function. I had the mixer set up to be controlled by Switch D. When Switch D is in the "2" position, it sends its own value (interpreted as "off") to the light control. In the "1" position it sends the sequencer strobe to the lights, and in the "0" position it sends its own value ("on") to the lights.
Posted by kallend | Oct 09, 2013 @ 01:00 PM | 9,967 Views
I set up my DX9 in the same way described in my blog entry for the DX8.

The .SLM file is attached.

Be aware that the flight modes are set from the pitch curves (pitch channel goes to the NAZA's "U" input), and the numbers probably need tweaking for different NAZAs. Check with Assistant that the values do indeed put the slider in the "blue" for each of the flight modes.
Posted by kallend | Mar 18, 2013 @ 10:09 AM | 10,105 Views
A word on GPS positioning
Lots of flyers have commented about their quad (Phantom or other) drifting immediately after takeoff when switching into GPS mode, and suggestions have included calibration of this and that or the other.


The GPS signal is subject to distortion from various sources, such as passage through the ionosphere, multi-path reflections, etc. so although it is very accurate, it cannot in one cycle compute a position to an accuracy better than 10 meters (maybe even more). In addition, the errors change with time over a period of a few seconds. So a NAZA GPS trying to hold its position will actually think it has moved even if the quad is stationary, and the NAZA will then try to correct by moving to the new "location". This is why taking off in GPS mode often results in tipping over - the NAZA is trying to correct for a perceived position error that doesn't really exist.

To overcome this pretty much all GPS makers use what is called a Kalman Filter. In essence this uses not only the current position the GPS antenna is reporting, but also information about previous position, speed, etc, to compute a more accurate and stable estimate of where the GPS really is. This "filtered" estimate is more accurate and doesn't drift as much. Because the filter uses previously determined positions, it doesn't become truly effective until after a bunch of previous positions have already been measured. Consequently we still get drift right after the GPS is turned on, but the amount of drift gets smaller and smaller the longer it has been on.

And this is the typical behavior we see in a quad with a NAZA GPS system - at first there is some (maybe a lot) of drift, but after a minute or two the amount of drift is reduced and the quad will hold position very well.

Kalman filter description: http://www.cs.unc.edu/~welch/kalman/Levy1997/index.html
Posted by kallend | Jan 27, 2013 @ 05:28 PM | 9,439 Views
Those who want to have switch selectable MAN, ATTI, GPS and Failsafe from a Spektrum DX8 (or higher) have generally been advised to use ACRO mode on the transmitter, and to set the flight mode ("U" input to the NAZA) on one of the 3-position switches, and then mix in the input from a 2-way switch to get to the Failsafe value.

This is how I did it at first, and it works, but it does involve (typically) setting endpoints on the flight mode channel to achieve the MAN and GPS values, using subtrim to ensure that ATTI is in the right place, and then programming the programmable mixers to get the failsafe.

However, this struck me as an overly complicated solution to a simple problem, and one that is likely to be confusing if you come back in 4 months time and need to change something and can't recall why it's set up that way.

What I ended up doing was using HELI mode instead. This allows the TX "pitch" channel (Channel 6) to be used for the "U" input on the NAZA. So be sure to connect the Rx channel 6 output to the NAZA's "U" input.

I set up the new model in the TX memory as a "1 Servo swash type NORMAL" HELI (this is the default so you don't actually have to do anything). All this means is that one channel is dedicated to each of the "elevator", "aileron" and collective pitch functions with no weird mixing involved. Connect the Rx throttle, elevator, aileron and rudder outputs to the corresponding NAZA...Continue Reading
Posted by kallend | Jan 24, 2013 @ 02:07 PM | 21,532 Views
In order to use the "Return to Home" (RTH) feature on a NAZA M controller in the event of radio signal loss, the receiver must be capable of sending an appropriate signal on the flight mode channel (NAZA "U" input) when the signal loss is detected by the receiver. The feature is called "preset failsafe".

Not all Spektrum receivers (and their clones ) can do this, and some which can do it have no instructions in the user manual.

The procedure to set it is as follows.


1. Plug a USB cable into the NAZA's USB port, connect to a USB port on a PC and run the Naza Assistant software on the computer. Ensure that the relevant Tx channel is set to the value that highlights the NAZA Assistant's "Failsafe" on the "Calibration" page of the Assistant. Depending on the Tx mode you use to set up the model (HELI or ACRO) this is likely to be channel 6 (HELI) or channel 5 (ACRO). Then turn off the Tx, but leave the switch(es) in the position you chose for "Failsafe". Move the throttle stick to a value above 10% (I use 40%).

2. Put the "bind" plug into the receiver.

3. Turn on the receiver and wait for the flashing light.

4. REMOVE THE BIND PLUG while the Rx is still powered up.

5. Turn on the Tx in bind mode, and wait until the Rx signals that binding is complete. Depending on how you set up the Tx "Warnings" you may have to...Continue Reading