Sebastian, thx for explaining, indeed i see the problem… i will experiment a bit with this setup before rebuild the other way around… thx anyway
I’m not using NAVIO+ for this rover yet. I’m still waiting for mine.
I’m using this controller for the servos: Pololu - Micro Maestro 6-Channel USB Servo Controller (Assembled)
For the 4G I’m using a wireless router: https://nettbutikk.telenor.no/mobilt-bredband/huawei-ruter-4g-e5372-telenor-b2c/
(I’ve recently ordered a 4G usb modem I will connect directly to the RPi)
To control the rover I’m using a web soctet server (Tornado) and a phyton html web page all hosted on the RPi. I basically locate the IP of the router and browse the RPi from my computer. (I had to switch the APN to enable a IP that was accessible) The latency using web sockets is around 100-150 ms for the controls.
For the video the latency varies a little with resolution, framerate and connection quality. But with 30fps 800x600 I get around 300ms latency. With full HD around 500-1000ms. I can change video mode while it is driving. 4G is much better than 3G. I tried different video codecs, but Gstream worked the best. It is not perfect, but good enough to drive it through the camera at a little more than walking speed.
The camera and lights support 360 panning and tilt. I’m using these lights:
Pan servo:GWS 360 Degree Sail Winch Servo - www.readymaderc.com
I’ve been sitting inside by my computer and driving around in the neigborhood several kilometers away. The 5000 mah battery lasts 30-50 minutes.
To read the voltage of the battery I’ve simply mounted a LED voltmeter in front of the camera.
I can posts some pictures and source code if anyone is interested later. (I’m out traveling now)
I’m planning on flying a glider back from the edge of space using a Navio and my own custom autopilot code!
The current off-the-shelf autopilots (APM, etc) would require extensive modification (both hardware and software) in order to work at such high altitudes (for example, standard APM 2 GPS module will cut out above 18km) and with a custom, unpowered glider.
So, I’ve set out to build my own autopilot from scratch. Navio was by far the best hardware - suits my application perfectly and has a uBlox on-board (perfect high altitude GPS - will work up to 50km when I set it in flight mode).
Within the past few days I’ve started to write the code for the autopilot. Whilst this is ambitious, I’m hoping I can cobble something together that works - it doesn’t need to be as sophisticated as APM - just needs to stabilise and point in the right direction with the right pitch. How complicated can it be…?!! (famous last words…)
Plan is to perform some low altitude tests, hoisting the glider up using my hexacopter and then letting it go. If all is good - attach it to a high altitude balloon and off we go! I have done some ballooning stuff in the past but this is by far the most complex & ambitious project.
I’m in the process of building a quadcopter. I’ll use NAVIO + RPi for control and video feed (GStream) via a 4G USB dongle. (There is a EzUHF RX as backup)
The AUW is 1700-1800 gr with 12 000 mah 4S batteries 2C. (GEB8043125 batteries)
The ESC are inside the arms. And only componets missing from pictures is the RPi camera.
I have mounted 3w LED’s out on each arm.
The props are 17x5.5. I hope for a flying time around 40-50 minutes.
Here are some pictures:
Can’t wait to try it! 
Looks great!
Before proceeding to the flight, I’d like to recommend the following:
- Check that GPS SNR levels are good as LTE may interfere with it. It’s better to move GPS antenna away from the LTE dongle as much as possible.
- Use UDP for gstreamer, it provides better latency.
- Find a balance of resolution \ bitrate \ fps for gstreamer. Smooth videostream should be somewhere around 720p / 20fps / 1.5Mbs depending on the hardware and network. Bitrate is the most crucial characteristic.
Yes, I was wondering about that, if LTE will interfere with GPS. I will certainly test it and perhaps mount the GPS on a new and separate arm to get some distance to electronics and transmitters.
If internet connection fails and UHF rx is out of range, RTH is the only backup. Without GPS everything fails… so GPS is critical for sure… Perhaps I’ll look into a failsafe that turns LTE off if GPS is lost… then at least RTH will work…
I’ve already used GStreamer for a rover project with 4G, and it works surprisingly well. Have not tried UDP, will sure try to see it gets even better. Thanks for the tips!
ArduCopter consumes it’s piece of system resources, so it will affect gstreamer’s performance a bit. But RPi2 should provide enough resources for both when it’s supported.
Yes, got the RPi2… waiting for the image… 
(“Plan B” is a separate RPi A+ for video. Should not add more than 40 gr or so…)
@ogulbrandsen very nice build!
Antenna placement should be carefully planned. This will have critical impact on GPS performance.
Here is the best way to approach this:
- Follow this http://docs.emlid.com/Navio-dev/GPS-ucenter/ tutorial to connect to U-center software
- Take a look at C/N0 graphs. They show ration between signal and noise.
Ideally you would have a couple satellites reporting 48-52 dB/Hz and several more around 45. If you are closer to 40 or even 35
GPS performance could be degraded. With all systems running move antenna from one position to another and monitor C/N0 values.
Ideally antenna should be augmented by a 70x70 or at least 50x50mm ground plane (PCB material or copper foil will do just fine) placed directly beneath it.
Try to achieve best signal and you will have great GPS performance!
1 Like
Will the GPS from 3DRobotics, (which is quite expensive…), plug straight into Navio+?
http://store.3drobotics.com/products/3dr-gps-ublox-with-compass
Do you think it will offer better performance?
I guess having the compass in the GPS module might be an advantage.
3DR GPS will provide worse performance. It uses outdated receiver that is GPS only. Also, I’ve seen plots with SNRs from it - they are quite low.
@ogulbrandsen I have provided recommendations that are suited for any GPS system, there is nothing wrong with Navio+ GPS or antenna, it is just how RF compatibility works I would recommend doing this to anyone who is looking to improve GPS performance.
Even without additional ground plane performance will be better than with 3DR GPS. However if you like you can use it, it is plug and play.
Sure, I was not thinking there were any problems with the Navio+ GPS, and your advice applies to any GPS system. Thanks for the tips! I will for sure look into this further, once I get everything powered up.
I’m planning to build a new aerial vehicle (platform) equipped with a ROS framework
1 Like
I’m building a medium/large racing T3 collective pitch copter running Navio+ and ODROID C1, with a 3 axis gimbal hopefully with 3D imaging. The two front propellors will be on it’s own rotating axis so the copter can continuously spin 360 degrees around the pitch axis, along with both pitch and roll functions on the tail for optimal maneuverability and speed. So far about a month into the project…
Hi Ole
Great project.
Which software / script are you using for the 4G USB modem?
I did a speed test between Sakis and Uqmi.
See the result here.
http://uavmatrix.com/viewpost/2/62/116/5/PX4-PixHawk/Setting-Up-Raspberry-Pi-A--and-USB-3G-Modem#postid252
Hi all
I have buildt many aircrafts that are controlled by cellular network, which are awsome and really fun.
For my next project i will be using Odroid or RPI2 with RTK and Navio+ (when they release this kernel 
)
This will put all i need in one chunk, and hopefully eliminate all the extra stuff i needed before when using eg. pixhawk and RPI, and give me some extra processor power.
1 Like
Hei Bernt!
I’m actually struggling with the modem in the picture, the Huawei e3372. I’ve managed to switch it but I cannot connect. I’ve connected with an other USB modem, the Huawei e173. For this I’m using Sakis3G. But it is 3G. I want 4G.
(For the 4G connection on my rover I used wifi from a 4G router. Huawei E5375)
I’ve not given up on the Huawei e3372, it is the lightest 4G modem, but in case I fail, I have ordered a new modem that is on the list of supported modems for Sakis3G, the Huawei e3276. (only 21 USD at aliexpress)… If this fails too (which it should not) I’ll buy the Huawei e8278 4G USB modem (75 USD), where I can use WiFi to connect to the 4G modem
BTW: for video streaming, 4G makes a big difference. For telemetry, it does not matter.
Going to integrate e3276 soon on my navio+ RPi setup. Let’s keep in touch!
@fabiobortoli : yes I will report back my findings!
@Bernt_Christian_Egel : had a look at your blog, very impressive! I can see you’re already a “veteran” with flying by 4G. Navio+ should be just what you’ve been waiting for…