I am successfully using a 4G LTE network connection to send bidirectional telemetry AND HD (1280X1024 / 25fps) Video from my drones. The video is perfect, the telemetry is perfect - regardless of range (assumes 4G is available). I use my cell phone as a hotspot and connect using MISSION PLANNER on my laptop. The video is "snow free" and is viewed on CHROME or FireFox browsers.
The cost of all the equipment is under $100, but I do have to pay for a data plan ($15-$50/month) - and a small monthly amount for server time. The server setup is special to allow for the 4G<->4G connection. The telemetry data is encrypted, the video data is not (at this time, anyway). The system camera is non-standard but tiny.I can control the drone with a joystick connected through Mission Planner. The latency is 0.8 seconds - max. The total weight of the system is 100 grams. No equipment other than a computer running Mission Planner is needed on the "ground side" (except for a cell phone or other hot-spot).
I was thinking that others could use my setup as well. In that case I would have to set up multiple accounts on the server and manage them. Before I take this any further -
Would anyone else be interested in the setup I have?
Replies
Hi Charles
I am just getting into controlling "Bots" over the internet. I have a wheeled Rover that it is connected to a Joystick over the internet to the Rover using web sockets. I want to move into an area without a wifi or radio connection and therefore I am looking at a 4G dongle or MIFI. To be able to get connected I assume I would need to port forward the MIFI. Is this correct. If you can give some more details on the 4G coms side of things I would be grateful
regards
Max
How do you get the 551 USB modem working on the Raspberry Pi?
I use a Raspberry pi running SER2NET, AUTOSSH, WVDIAL, and a few other programs.
The switchover between 4G and RFD900 is done in a separate T
EENSY processor. The TEENSY handles a lot of object avoidance stuff too, since it understands Mavlink, and all the Mavlink traffic is going through it
Sushanth J said:
not speaking for OP, but with the Navio2 board I do this today with MavProxy via TCP, with Mavproxy you can multicast to different tagets
Sushanth J said:
The system seems to be a very useful backup to RFDs. You mentioned about a special server setup, can you please explain how you're pushing a mavlink stream to an online server?
I use an RFD900+, but I have put together a package (mostly from Texas Instruments) that gives me even more power than the RFD900. It consists of two boards and I will probably combine them into one someday.
It is a real headache that the FCC says I can use hundreds of watts on 915MHz (I'm a "ham") UNLESS I'm controlling a model - in which case I'm limited to 1 Watt. I'm thinking of using 433 MHz (which is legal for hams in the US) and should give even more range and less absorption from surrounding vegetation. The antennas have to be long, but on bigger aircraft that will be OK.
Ivan R said:
pretty nice, you should definitely do it....am kinda of doing the same thing, except manually, i run 2 simultaneous copies of MissionPlanner GCS, one connected via IP to the 4G modem and the other one serial to the RFD900x, either can fail and rarely are both down, but i am pretty impressed with the range of the RFD900x....Ive gone way out like 8 miles and still solid RSSI and since I fly beyond LOS way out in the middle of nowhere the 4G isnt as strong there, but the RFD has been impressive. I didnt mention but I run a Navio2+ board running linux, not a pixhawk, so there are a ton more possibilities I havent gotten to yet
Charles Linquist said:
I was surprised as well. But the cell companies build their antennas to "shove" the signal toward the ground in order to maximize coverage area. In my area (near San Jose, CA), there are totally dead spots in coverage at 300'. I did an exercise - I turned my cell phone ON as I was flying into San Jose airport. I got a signal at 5,000 ft when flying over Morgan Hill CA (10 miles from San Jose airport), but the signal then quickly disappeared and I could get NOTHING until I was 100' above the ground, ready to land at SJC.
But there are other areas (like Carmel Valley, CA) where the signal is great in the air. I think the difference (at least there) is due to the fact that some people live on the mountainsides, so they have to put more signal above the horizontal plane in order to get to those people.
Ivan R said:
I'll tell you a little more - I am strongly considering selling a package with everything set up. My package works with both APM and PixHawk controllers.
The controller always "talks" at 115Kbaud, but that is buffered and converted to 57.6Kbaud, but only when using 915Mhz. 4G/LTE always runs at 115Kbaud. I use a TEENSY processor for the failover stuff, since it has 3 hardware serial ports.
The data coming FROM the Flight Controller is sent out using 4G and 915Mhz simultaneously, while the TEENSY picks the best option for INCOMING data (either 915Mhz or 4G) and passes only good data to the flight controller. An algorithm prevents rapid back-and-forth.switching between the two and looks at timing, MAVLINK CRC , and packet sequence numbers in order to make its decision. The ground station does exactly the same thing.
The whole setup is amazingly reliable, and I generally don't have to worry whether or not 4G is available. It just works. Of course the 915Mhz channel does have a limited range. But I have had many instances where the 915Mhz backup came in awfully handy.
Charles Linquist said:
btw i just use a RPi3 with Huawei 4G USB dongle and mavlink telemetry/control via MP and also have RFD900x radios for backup and RC control...I connect MP to the RPi IP and another MP instance connected simultaneously via RFD900x and it also does standard RC control....no video yet thou
Ivan R said: