Monday, January 13, 2014

DJI Phantom Initial Setup and Problems -- Some Notes

As I mentioned, I am generally a year or two behind the bleeding edge when it comes to technology.  My friend Eric Cheng has been doing great work with remotely operated quadcopters (drones) and has a great blog post on how to get started at skypixel.org. 

I bought a DJI Phantom in December, when the price dropped.  I’ve been astounded at how easy this was to set up and the great tutorials provided on the DJI Phantom website.  I got my practice by flying a Syma X-1 which cost $35 from Amazon and is a small quadcopter that is a great way to get practice flying these drones. 

Most bleeding-edge folks will buy the new Phantom 2, but I am still practicing with my Phantom I.  I have put a GoPro Hero on it, set to take still images every 0.5 seconds, and I’ve flown it a couple of times in the very basic GPS mode near my house.  I had good luck, but I don’t want to lose a $500 machine (well, $800 if you count the GoPro) just yet.  When the drone gets too high or far away, it is dang hard to tell whether it is coming at you or going away when you move the controls.  It is difficult to tell where the nose and rear of the drone is when it is far away. 

To solve this problem, the Phantom has a more advanced mode called IOC or Intelligent Orientation Control.  If you choose Home Course Lock, then pressing the drone to go forward will make it go forward in relation to where you are.  I have yet to try this, but it sounds great.  If the drone gets too far away from me, I’ll just pull the control stick back to make the drone go backwards, and it should come back to me.  Forward or backwards becomes in relation to me rather than how the nose happens to be pointing. 

For some reason, in order to enable IOC (which actually has two modes, course lock or home lock), you have to connect the Phantom to a PC via a USB extension cable, power on the transmitter, power on the Phantom, and then install their Naza M Assistant software.  Once inside the Assistant software, you navigate to the Advanced tab and click on a box enabling IOC. 

I tried this on Sunday, when I had some free time.  I list the steps and problems below for anyone else going through this. 

I.  Initial problems. 
Remember to always turn on the transmitter first.  Then turn on the Phantom drone itself.  This is a hassle when you are in an office at a computer. 

I downloaded the Naza Assistant software and drivers, but I was unable to enable the IOC.  At some point, a message came up and forced me to download the new firmware 4.2.  I did so.  I was then able to go into the software and enable IOC.  However, I remembered a message that after installing the new firmware, I needed to install the new parameters file (I still don’t know what this does).  After I did this, I could no longer enable IOC!!!

After installing the new parameters file, the GPS mode as indicated in the Naza Assistant software was always set to failsafe.  Normally, I could click the GPS/ATT toggle switch from GPS to ATTI mode, and the software would show this change.  Once the new parameters were installed, however, I could not switch to GPS or ATTI mode using the transmitter.  I also could not check the box next to “enable IOC”. 

After reading the manual and some forums (for some reason, on this Sunday, DJI very helpfully removed all the video tutorials that talked about the IOC modes and calibration software from their website, and I could not find the tutorials on YouTube or anywhere else), I decided to start from scratch and recalibrate the compass on the Phantom manually.  Unfortunately, since the video tutorials were removed, I had to rely on memory.  It’s taken me a couple of days now, experimenting, before I finally got the compass recalibrated.  Of course, this morning I discovered that this procedure is pretty well documented in their Naza user guide (not the place you’d expect to find it, in the Phantom Quick Start guide). 

Here are the steps:
1.  Do the usual: turn on transmitter first, then the Phantom. 
2.  Toggle the transmitter’s top right toggle between GPS and ATTI ten times.  The Phantom will go green on its LED. 
3.  Holding the Phantom horizontally, pick it up and rotate your body clockwise 360 degrees.  The LED should go green again. 
4. Hold the Phantom nose down and rotate it 360 degrees.  The LED should go off. 

If the Phantom’s LED blinks yellow-red, then the compass has not been calibrated properly, and you need to repeat the process above.  I may have gotten the lights and beeps wrong; check the manual. 

The first time I did this, the Phantom flashed yellow-red-red and the propellers would not start up.  I gave up for the night.  I got flashing yellow lights at one point also, which meant the same thing, I think. 

At some point, I was able to go back into the Assistant software and enable IOC.  I think. 

The next day, I tried contacting DJI’s California office for help.  You can see my email to them below.  In short, don’t count on DJI for good technical support. 

After some more reading of forums and their manuals, I decided to try recalibrating the transmitter.  There’s a description of how to do this in their Phantom Advanced Manual.  I did this twice.  The transmitters LED used to be red when I turned it on in the beginning, when everything worked.  It was green when I had trouble.  After re-calibrating the transmitter twice, it was red again.  I have no idea if that is the way it should be or if this just means that my transmitter batteries are low.  Whatever.  After recalibrating the transmitter, I could once again get my Phantom to fly.  Now I have to go through the manuals and figure out the technical stuff involved with IOC. 

Some notes I collected:
PPM is usual transmitter mode which is set in Naza Assistant Software. 

Some forum comments:
Question: Everything seems fine, but the motors wont start. I have checked almost everything that I could find on the internet about this problem, but no one seems to have this problem.

Answers:
This sometimes can occur if your sticks are out of calibration. Hook up the NAZA assistant and run the calibration routine to make sure your control sticks are properly registered. 

did you pull both sticks down to the bottom corners and hold them there? That should start them up.

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