fangin.com RC, photos & tech

24Jun/122

EagleTree Logger V4 on the DJI Naza F450

The first full flight with the EagleTree Logger v4 running on the DJI Naza F450 with GPS. The first 140 seconds show little activity while I plug things in and wait for GPS lock. When I eventually takeoff with a 4S 2200 Nano-tech LiPo, the voltage drops to 15.4 Volts and within 40 seconds drops down to 14.8 Volts as you'd expect from a 4S battery. It seems to hold the voltage fairly well throughout the flight keeping in mind it was fairly sedate backyard hovering with the GoPro onboard and recording. The voltage seems to start decling quickly after about 500 seconds where there's a few spikes in current and corresponding drops in voltage where I did a few short sharp rapid ascents with the throttle wide open. At about 670 seconds, the voltage drops too far and the second level protection kicks in where the Naza automatically descends. For my liking, it descends too rapidly but I'm not sure if that might be the result of setting the second level voltage protection level too low so there's nothing left in the pack to land safely. I wonder if I up the Voltage level, will the descent be more controlled when the Naza takes over.

I got about 2,000 mA out of the 2,200 pack which seems fairly good. The quad is loaded up with a GoPro, Naza GPS, Eagletree logger and Eagletree GPS so it's carrying a little more weight than usual. 8.5 minutes hover time seems pretty good I reckon. Average current draw with the 8" props is around 13 amps with a peak at 24.5. The 30Amp ESCs should be more than comfortable to handle that load.

This was the second flight with the DJI Naza GPS and all went well. There's been many rumours floating around the forums that the GPS doesn't work so well in the Southern Hemisphere (SH) and after my first flight I was worried they were right. During that flight, whenver I activated GPS mode the Quad would veer off to the left and never recover. After entering the X,Y,Z co-ordinates in the software configuration and mounting the GPS on the stick, it works great. At most the drift was maybe 1 meter but most of the time it seemed to hold position withing bout 30-50cm.

Next mission - Test the Return to Home (RTH) feature. I'll need a bit more space than the backyard though because it's supposed to ascend 20 meters, return to base, then land. Need to make sure there's no trees in the way. At the moment, the only way I have to trigger failsafe mode is to switch off my transmitter. That could be a bit nerve racking. In all my years of RC flying, I've never deliberately (or accidentally) switched off my Tx in mid-flight. I might have to make sure to have the video camera recording that one.

 

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  1. Hi im from mexico im assembling my dji f450 with naza and gps, right now im waiting for the lipos to arrive so im taking my time to assemble all and yesterday i attached the motors and the arms , today esc and started to plug receiver (rx 802) to the naza mc but right now im having a little trouble on how to mount the gps as well as entering the xzy centimeters on the dji sw assistant i really dont undestand the image can you help me a little bit on that, also i you know something on the fail safe for my devo 8s would appreciate, im from mexico so im sorry if my english is not so well.

  2. Hi,

    I took some photos and labelled them with the co-ordinates. You can read the description here http://fangin.com/blog/2012/06/26/dji-naza-gps-xyz-co-ordinates/

    I don't have any experience with your receiver. All I can say is on mine, I turn on the Tx, set the sticks to where I want them in failsafe, hold the "Set" button on my rx while powering up the receiver. These positions are then saved in the receiver and can be verified by switching off the Tx and watching what happens in the "Calibration" screen of the Assistant software. All the cursors should go to the predefined failsafe locations.

    Let me know how you get on with the X,Y,Z co-ordinates.


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