Flytrex Live 3G Released - Review

[DrJoe]

Dji fan brings up so very good points. This board is based on our experiences, which isn't perfect. My experience has been that of poor performance from a cheap GPS tracker, including failure to respond to location requests from time to time, and a quick draining battery of the tracker unit. The crash survivability of my stand alone GPS tracker has been a concern of mine, but I have had no experience with a lost phantom.

Where I fly, there is excellent 3G coverage. I like the additional data that Flytrex provides. Their site is another way to enjoy the hobby. I like that the data is streaming live, and that I instantly know the status. If it wasn't transmitting its data, I would know instantaneously, and could make a choice to cancel or scrub the current mission if I was so inclined.

While expensive, my experience is that the Flytrex 3G Live provides great value, despite the cost. Your experience may differ.

 

[p fandango]

sorry i haven't read up on the 3g Live, but will it record all its information onto the memory card during a flight even if it can't get 3g signal (ie will it work as a Core if it can't do it live)

 

[amitregev]

Same here, I have the 3G and an Android device and am willing to help test it out!

Thanks guys!! I'll post more details in about 3 to 4 weeks when we have something ready for some initial testing.

 

[amitregev]

Flytrex Live 3G is engineered to operate with a few specific flight controllers. I don't think just adding a dedicated GPS for the Flytrex Live 3G is an operational option.

I also read that the Flytrex Live 3G operates in parallel with the FC'c GPS, and would not take the GPS out if it failed. However, until someone actually experiences this scenario, I have to assume that is just the theory of operation at this point. Anytime you ad something to a system, and it fails, there is risk to the system based on its level of interaction with the failed component.

As for understanding the differnece between a FLytrex Live 3G unit and a regular GPS tracker device, the only function added to the sUAS by a GPS tracker is a location/tracking capability. The Flytrex Live 3G adds multiple new capabilities to a sUAS... last seen position for loss location, live tracking for flight following/observation, system flight logging for record keeping, and social networking via Flytrex's servers. There are advantages and disadvantages to each relative to being an integrated addition or a standalone addition to the sUAS. The Flytrex is integrated and depends on operating correctly up to a crash, and does not have to operationally survive a crash to provide location information for finding the crash site. A GPS tracker is independent and does not automatically operate up to to a crash, and must operationally survive a crash to report back to an inquiry as to the its current location. Different risk assessment. Nothing is 100%.

Great points, Thanks
Also, as I understand this unit needs good 3G coverage, which may not be available everywhere whereas a regular gps tracker uses sms, which is 100% available in all areas. Another good feature of beeper which activates upon calling and comes as a standard feature in most of the regular gps trackers, is missing in the 3G Live. From my limited experience, GPS location is never accurate beyond a few meters and that's a lot of area to search especially if your sUAS crashed some where in dense forest with trees. Therefore in my opinion, a beeper would be of great help/necessary to zero in on exact location of the sUAS. But then again that's just my opinion.

I just noticed that the actual price of the 3G Live comes to approx $225 USD with express shipping($25). The regular airmail option($5) is impractical as it will take up to 30 business days as stated on their website. Is this really true, 30 days for shipping within the US? Or am I missing something here. Thanks a lot

Hi Djifan

Regarding our shipping options -- the air mail option usually goes much faster. From our experience, this usually arrives within 7 to 8 business days. We list it as 30 days since this is the "official" time reported by the shipping provider, but since the route to the states is very active shipments actually gets there much (much) faster. Shipping to other locations might be somewhat slower with air mail, but it's pretty fast when shipping to the states.

Cheers!

 

[amitregev]

sorry i haven't read up on the 3g Live, but will it record all its information onto the memory card during a flight even if it can't get 3g signal (ie will it work as a Core if it can't do it live)

Yes. The Live includes an internal memory chip of 16mb that records all of your flight data from the moment it is powered up. The data is stored in the internal memory regardless to whether you currently have 3G coverage or not.

Using our Live Programmer app on our site you can extract and sync missions stored in the internal memory with your Flytrex account. We recommend using this tool only in the event that some flight missions data is missing from your account in the event of flying in areas without 3G signal.

Up until now, I don't think we had any report like this from any of our Live 3G users, but this is of course possible if flying in far remote areas.

 

[Chuck26287]

There's one other consideration I had when deciding on the Flytrex Live 3G over a stand-alone GPS tracker. I wanted a system that would allow me to actually verify the GPS position of my MR before I launched it. It sounds like any GPS reporting device would suffice, but not so. I want to know the GPS location my flight Controller is using to make its logic decisions and control actions in flying my MR. To know this, you must be tied in to the MR's GPS system, not looking at what a standalone tracker is reporting. There could easily be a difference between the two.

The scenario I'm looking at involves something we've probably all seen on our phones when plotting their GPS position on something like GoogleMaps. You bring up your phone's GPS position, and the blue dot is far from where you know you are, providing a false GPS position. This sometimes corrects almost immediately, or can sometimes take a little moving the phone around to get it to adjust to an accurate position report.

Now consider what happens if you fire up your MR, and like in the above phone GPS scenario, the MR GPS is reporting a false position to the flight controller when it acquires the minimum satellites and sets the home position in memory. You now have an unknown home position and don't know it. You think all is fine and launch. Something happens during the flight and RTH is triggered. Your MR now goes to an unknown to you home position, and you think you just experienced a flyaway when in fact the flight controller performed correctly.

Another scenario can be enacted almost immediately under certain conditions. If your incorrect home position is farther from you than your horizontal distance limit in your software config, and your GPS position suddenly corrects itself as soon as your MR start moving a little (like right after launching), almost immediately, your flight controller sees your MR as outside its designated distance from your HP, and takes off heading back to its designated flight area. Again, you see it as a flyaway, but the flight controller is performing correctly.

Both of these scenarios could be to distances that only make you think "what the heck was that weird flight movement", or to the degree of your MR being lost due to traveling out of sight and/or control range, all depending on the degree of error in that original GPS position reported to and used by the FC.

Now please realize this is just theorizing (some mine and some other people's), and I can't even say whether this theory is possible as I don't have an intimate knowledge of the Naza M V2 FC. However, having a way to see and verify, before launching, the true GPS position that the FC is utilizing will allow me to manually set my HP just before I launch to the known current launch position. I then know I launched with an accurate GPS reported position, and I know my HP is truely my launching point. I now don't have to worry about this theory being correct, or these scenarios causing me unexpected flight control actions. A non-integrated GPS reporting device will not tell you what info your FC is using.

 

[flyNfrank]

I recently mentioned an ongoing issue I have had with all flytrex using the GPS Wiring Harness. I have always had a inconsistent elevation reading. So I shared the issue with Amit and he was interested in finding out more about it. I then began working on what I could with what I had to work with, and was able to send a response back to Amit. Below is some of what I came up with. And now I'm waiting to hear back from Amit.

Btw, I'm sure most will have a interest the amount of satellites at start up, but the elevation won't mean much unless you are into using Dashware.

I just spent a couple of hours working on this. I can give a general description on what is taking place. but not actual data in all areas. In a nut shell, the addition of the Live and the Live's wiring harness reduce power to the quad's GPS puck. Because of this, it creates a lag to everything dependent to the gps data. Not only does the flytrex logger start up with inconsistent data each time, but the quad starts out with receiving less satellites during warm up. With Live & Harness, 4-6 at warm up. Without Live & Harness, 7-9 satellites. If you increase the rpm's and hold them there without launching the quad, you can get the number of satellites received to raise. This method helps the gps puck to get the needed amount of volts due to the loss mentioned.

I actually use two flight loggers when I'm making top speed flights. Other then the flytrex logger I use additional flight logger that records it's data straight from the quad.

 

[DrJoe]

With Live & Harness, 4-6 at warm up. Without Live & Harness, 7-9 satellites

Frank, I'm very interested to hear the results of this conversation. I had posted about my difficulty attaining satellite lock with Flytrex Live 3G on my P2V+ ver 2. After tucking the harness under my foil shield mod, all was fine again. I think that what happens is the long harness cables becomes much more susceptible to the RF interference generated by the WiFi unit. Once the majority of the harness was shielded, I had no further issues (grabbed 7 satellites instantly, 10 in flight). I was considering placing ferrite donuts on the harness, or perhaps a shield of foil around the entire harness, but my first flight test after tucking it under the shell's foil made those modifications unnecessary, at least for me.

I did not notice a power/voltage issue, but I'll see if I can get more satellites with throttle on the ground. Interesting.

 

[flyNfrank]

There's one other consideration I had when deciding on the Flytrex Live 3G over a stand-alone GPS tracker. I wanted a system that would allow me to actually verify the GPS position of my MR before I launched it. It sounds like any GPS reporting device would suffice, but not so.

As you can see I removed 90% of the quote above. That has to be the most crap I have read from this forum, ever. All of what was mentioned was meaningless. Neither the vPlus or Flytrex equipped quads are capable of this mystery position location junk. And if your phone does display something like that, then it means you haven't updated your phone since 1999.

 

[flyNfrank]

With Live & Harness, 4-6 at warm up. Without Live & Harness, 7-9 satellites

Frank, I'm very interested to hear the results of this conversation. I had posted about my difficulty attaining satellite lock with Flytrex Live 3G on my P2V+ ver 2. After tucking the harness under my foil shield mod, all was fine again. I think that what happens is the long harness cables becomes much more susceptible to the RF interference generated by the WiFi unit. Once the majority of the harness was shielded, I had no further issues (grabbed 7 satellites instantly, 10 in flight). I was considering placing ferrite donuts on the harness, or perhaps a shield of foil around the entire harness, but my first flight test after tucking it under the shell's foil made those modifications unnecessary, at least for me.

I did not notice a power/voltage issue, but I'll see if I can get more satellites with throttle on the ground. Interesting.

Yeah your thoughts on interference is part of it. This is the reason why I had ran my harness across the top ov the battery compartment area. I wanted it to be clear of the stock antenna wires as possible. On the throttle up test, you just want to find that sweet spot where it wont lift off the pad. Or, you can also notice when you do launch the satellite number will increase. However, every once in awhile the satellite number will not increase until above 200+ feet. It's like dji software has time windows that come into play under certain conditions. I'm speculating on that because I have no other idea what could make the quad not allow the numbers to increase until after X amount of time.

I haven't spent anytime yet on a fix, but I do feel like this will be a inexpensive fix.

 

[djifan]

Dji fan brings up so very good points. This board is based on our experiences, which isn't perfect. My experience has been that of poor performance from a cheap GPS tracker, including failure to respond to location requests from time to time, and a quick draining battery of the tracker unit. The crash survivability of my stand alone GPS tracker has been a concern of mine, but I have had no experience with a lost phantom.

Where I fly, there is excellent 3G coverage. I like the additional data that Flytrex provides. Their site is another way to enjoy the hobby. I like that the data is streaming live, and that I instantly know the status. If it wasn't transmitting its data, I would know instantaneously, and could make a choice to cancel or scrub the current mission if I was so inclined.

While expensive, my experience is that the Flytrex 3G Live provides great value, despite the cost. Your experience may differ.

Thanks DrJoe, i'm just a newbie trying to learn from experts like your good self. Thanks again for sharing your valuable experiences.

I just noticed that the actual price of the 3G Live comes to approx $225 USD with express shipping($25). The regular airmail option($5) is impractical as it will take up to 30 business days as stated on their website. Is this really true, 30 days for shipping within the US? Or am I missing something here. Thanks a lot

Hi Djifan

Regarding our shipping options -- the air mail option usually goes much faster. From our experience, this usually arrives within 7 to 8 business days. We list it as 30 days since this is the "official" time reported by the shipping provider, but since the route to the states is very active shipments actually gets there much (much) faster. Shipping to other locations might be somewhat slower with air mail, but it's pretty fast when shipping to the states.

Cheers!

Thanks a lot Amit, appreciate the prompt clarification. Cheers & kudos for an amazing and unparalleled product!

There's one other consideration I had when deciding on the Flytrex Live 3G over a stand-alone GPS tracker. I wanted a system that would allow me to actually verify the GPS position of my MR before I launched it. It sounds like any GPS reporting device would suffice, but not so. I want to know the GPS location my flight Controller is using to make its logic decisions and control actions in flying my MR. To know this, you must be tied in to the MR's GPS system, not looking at what a standalone tracker is reporting. There could easily be a difference between the two.

The scenario I'm looking at involves something we've probably all seen on our phones when plotting their GPS position on something like GoogleMaps. You bring up your phone's GPS position, and the blue dot is far from where you know you are, providing a false GPS position. This sometimes corrects almost immediately, or can sometimes take a little moving the phone around to get it to adjust to an accurate position report.

Now consider what happens if you fire up your MR, and like in the above phone GPS scenario, the MR GPS is reporting a false position to the flight controller when it acquires the minimum satellites and sets the home position in memory. You now have an unknown home position and don't know it. You think all is fine and launch. Something happens during the flight and RTH is triggered. Your MR now goes to an unknown to you home position, and you think you just experienced a flyaway when in fact the flight controller performed correctly.

Another scenario can be enacted almost immediately under certain conditions. If your incorrect home position is farther from you than your horizontal distance limit in your software config, and your GPS position suddenly corrects itself as soon as your MR start moving a little (like right after launching), almost immediately, your flight controller sees your MR as outside its designated distance from your HP, and takes off heading back to its designated flight area. Again, you see it as a flyaway, but the flight controller is performing correctly.

Both of these scenarios could be to distances that only make you think "what the heck was that weird flight movement", or to the degree of your MR being lost due to traveling out of sight and/or control range, all depending on the degree of error in that original GPS position reported to and used by the FC.

Now please realize this is just theorizing (some mine and some other people's), and I can't even say whether this theory is possible as I don't have an intimate knowledge of the Naza M V2 FC. However, having a way to see and verify, before launching, the true GPS position that the FC is utilizing will allow me to manually set my HP just before I launch to the known current launch position. I then know I launched with an accurate GPS reported position, and I know my HP is truely my launching point. I now don't have to worry about this theory being correct, or these scenarios causing me unexpected flight control actions. A non-integrated GPS reporting device will not tell you what info your FC is using.

Sorry Sir, I wasn't able to follow that, maybe because i'm too new in this hobby so I will let the experts comment on this. Thanks though for sharing your thoughts.

I recently mentioned an ongoing issue I have had with all flytrex using the GPS Wiring Harness. I have always had a inconsistent elevation reading. So I shared the issue with Amit and he was interested in finding out more about it. I then began working on what I could with what I had to work with, and was able to send a response back to Amit. Below is some of what I came up with. And now I'm waiting to hear back from Amit.

Btw, I'm sure most will have a interest the amount of satellites at start up, but the elevation won't mean much unless you are into using Dashware.

I just spent a couple of hours working on this. I can give a general description on what is taking place. but not actual data in all areas. In a nut shell, the addition of the Live and the Live's wiring harness reduce power to the quad's GPS puck. Because of this, it creates a lag to everything dependent to the gps data. Not only does the flytrex logger start up with inconsistent data each time, but the quad starts out with receiving less satellites during warm up. With Live & Harness, 4-6 at warm up. Without Live & Harness, 7-9 satellites. If you increase the rpm's and hold them there without launching the quad, you can get the number of satellites received to raise. This method helps the gps puck to get the needed amount of volts due to the loss mentioned.

I actually use two flight loggers when I'm making top speed flights. Other then the flytrex logger I use additional flight logger that records it's data straight from the quad.

Now this is exactly what I am concerned about. The live 3g, which no doubt is possibly the best black box out there, allegedly interfering with or degrading the basic flight/functioning of the phantom. I truly hope Amit has a valid/other reason or explanation for this behavior. Please please do keep us updated as this is surely a deal breaker for me. Thanks

 

[amitregev]

I recently mentioned an ongoing issue I have had with all flytrex using the GPS Wiring Harness. I have always had a inconsistent elevation reading. So I shared the issue with Amit and he was interested in finding out more about it. I then began working on what I could with what I had to work with, and was able to send a response back to Amit. Below is some of what I came up with. And now I'm waiting to hear back from Amit.

Btw, I'm sure most will have a interest the amount of satellites at start up, but the elevation won't mean much unless you are into using Dashware.

I just spent a couple of hours working on this. I can give a general description on what is taking place. but not actual data in all areas. In a nut shell, the addition of the Live and the Live's wiring harness reduce power to the quad's GPS puck. Because of this, it creates a lag to everything dependent to the gps data. Not only does the flytrex logger start up with inconsistent data each time, but the quad starts out with receiving less satellites during warm up. With Live & Harness, 4-6 at warm up. Without Live & Harness, 7-9 satellites. If you increase the rpm's and hold them there without launching the quad, you can get the number of satellites received to raise. This method helps the gps puck to get the needed amount of volts due to the loss mentioned.

I actually use two flight loggers when I'm making top speed flights. Other then the flytrex logger I use additional flight logger that records it's data straight from the quad.

Hi flyNfrank

Where do you have the Flytrex Live installed? Can you post a picture showing the installation? Thanks!

 

[Chuck26287]

There's one other consideration I had when deciding on the Flytrex Live 3G over a stand-alone GPS tracker. I wanted a system that would allow me to actually verify the GPS position of my MR before I launched it. It sounds like any GPS reporting device would suffice, but not so.

As you can see I removed 90% of the quote above. That has to be the most crap I have read from this forum, ever. All of what was mentioned was meaningless. Neither the vPlus or Flytrex equipped quads are capable of this mystery position location junk. And if your phone does display something like that, then it means you haven't updated your phone since 1999.

Hi Frank. Thanks for your comments. As your post is clearly intended to be insultive, I can assure you that you did far better... it was actually quite belittling. You know, I'm pretty new to multirotors. I've been lurking the forums for some time, and I finally started getting involved by posting probably a few weeks ago. I don't think I've offered much to any of the various forums, but I started participating. That's always the first step to a new person becoming a contributing member of any forum community. I apologize for doing so with a load of crap so far below you, and rest assured, it won't happen again.

When I post I usually try to offer an explanation of my reasoning as to my position or logic on a topic. For example, this is a thread many people may be reading to decide on the purchase of the Flytrex Live 3G. I could have said it's a good product and I bought it (two, actually). However, I think most people are interested in the why factor, so I tried to explain one specific aspect of that (I want to verify the GPS position that my FC is using before I launch). Your comment quoted above, while a very effective insult, offers no substantiation, and lacks any substance other than the insult itself. Therefore, I would like to pick your brain a little to learn from my stupidity.

First of all, what specifically was crap? I assume to be considered crap, my comments have to at the very least be known by you to be wrong. What points of theory or understanding of the FC operation was I wrong on? I should specify I'm not asking about the phone displaying a temporarily incorrect GPS position. The occasional and unpredictable occurrence of this I know to be fact and I don't need your particular input or assumptive opinion on it. I used my iPhone 5s (always kept updated to the latest version of iOS) 3 or 4 times a week all last summer with a GPS tracking program for recording outdoor runs. I experienced this initially incorrect GPS position at least twice over the summer, and once about two weeks ago. I will attribute your comment about my phone to simple ignorance, and the human nature of assumption.

As I have experienced it and I know this situation can occur in a smartphone's GPS system, I gave it some credibility when I saw a youtube video ( took me forever to find it again, but here it is: https://www.youtube.com/watch?v=_ge3GuhEDRM ) in which someone else indicated they had experienced it, and they speculated about it happening in MR GPS systems, and how the FC would respond to initially incorrect, then changing GPS position data if this happened during the critical time when the FC is setting the HP. It was suspected that some people may have experienced what they thought were uncontrolled flyaways, when for a misunderstood reason, the FC was responding with proper control for the given data being fed to it. As it appears you have reasonable analytical troubleshooting skills, I assume you know sometimes what we assume is correct is not, and likewise, sometimes what we assume is incorrect may be totally correct, we just don't see why yet.

As I said before, this is all speculation, but trying to troubleshoot it is where the Flytrex Live 3G comes in. The Flytrex Live 3G can be used as a tool to verify that your MR FC correctly sees the GPS location of your MR. Unless you were to catch this false location condition actually happening to the GPS system on your MR, if that's even possible, you won't be able to prove that it's causing any flyaway conditions. However, you will be able to start each launch knowing the flight will NOT be affected an incorrect HP in memory. That's worth something to me. There are just too many unexplained flyaways of these MR aircrafts for me not to feel it's worthwhile to try and prove a possible cause, or at least eliminate the suspicion of a cause for my flights when I have the tools to do so. The Flytrex Live 3G is that tool.

I would appreciate being corrected on all of my incorrect understandings of how the FC would respond to the given scenarios I mentioned, even though you know the scenarios could never exist. It can be painful, but I'd rather learn from my stupidity than perpetuate it to others reading it.

Note to the Moderators: While this has a basic relevance to the Flytrex Live 3G Review thread, I realize this reply can be seen as moving from the original thread's topic. If it would be better to move the reply to a new thread, I understand.

 

[flyNfrank]

Hi flyNfrank

Where do you have the Flytrex Live installed? Can you post a picture showing the installation? Thanks!

As I mentioned, this is not a Live 3G only problem. It has to do with the addition of the GPS Harness. It doesn't matter where I have had the harness routed, the results have been the same straight across. I have seen it on the Core2, Live Tracker, and Live 3G. The 1st time I ever noticed something was wrong was when I used the Core2. I had wrote the Flytrex Support and asked why on all graph before launching there was all this added line garbage that looked like a rats nest. I was asked to give more detail on what it was I was referring to, and I responded with a description of the graph looking like the Core2 had been attached to a Fly's *** in the way the line on the graph just went in circles all over the place. I'm not sure if you remember that or not, but I remember someone on the support team there responded with a "Great expression by the way" I do remember this particular issue with the rat's nest description wasn't always a issue. It did appear out of nowhere. Due to the timing of this question, I never did get a response on it. They were deep into trying to launch the Live Tracker at this time. It was a issue to me cause it made the dashware map gauges look messed up with all the extra scribbling.

As I mentioned in one of my last post I don't think this will a expensive fix. It could be something as simple as adding a resistor or diode inline. I have experienced similar problems like this on other devices in the past that use the same type of ground system the vPlus uses. Amit will probably have this figured out in a day.

I have seen some others in other threads say they were getting a decent amount of satellites, but after adding the harness the number has dropped.

Let me add that last night when I looked over the flytrex flight logger .csv file from my last flight, right at the point where I lifted at full throttle, the volts dropped a 1/2 volt, and the satellite switched from 6 to 7 at that same point & time. And prior to the launch the elevation/altitude will show some -2 -1, but at throttle up it goes right to "0". ****...the more I start to think about this now it very well could be a corrupt ground system. So here is when adding a inline diode would clean it up. A diode is like a check valve, it allows the current to flow in one direction but not the other. Some devices allow current (power) to bleed into it's own ground which then corrupts the ground system it's attached to. Then some, if not several other things in the system get confused, sensors can display the wrong reading and so on. This deal is not as bad as it sounds because no devices are grounded to any metal. When what I described above takes place with a metal ground is involved would be when things are much more effected. This is not one of those cases, so IF what I described is indeed into play, it's not that serious. Ok enough..I need to stop rambling.

 

[flyNfrank]

There's one other consideration I had when deciding on the Flytrex Live 3G over a stand-alone GPS tracker. I wanted a system that would allow me to actually verify the GPS position of my MR before I launched it. It sounds like any GPS reporting device would suffice, but not so.

As you can see I removed 90% of the quote above. That has to be the most crap I have read from this forum, ever. All of what was mentioned was meaningless. Neither the vPlus or Flytrex equipped quads are capable of this mystery position location junk. And if your phone does display something like that, then it means you haven't updated your phone since 1999.

Hi Frank. Thanks for your comments. As your post is clearly intended to be insultive, I can assure you that you did far better... it was actually quite belittling. You know, I'm pretty new to multirotors. I've been lurking the forums for some time, and I finally started getting involved by posting probably a few weeks ago. I don't think I've offered much to any of the various forums, but I started participating. That's always the first step to a new person becoming a contributing member of any forum community. I apologize for doing so with a load of crap so far below you, and rest assured, it won't happen again.

When I post I usually try to offer an explanation of my reasoning as to my position or logic on a topic. For example, this is a thread many people may be reading to decide on the purchase of the Flytrex Live 3G. I could have said it's a good product and I bought it (two, actually). However, I think most people are interested in the why factor, so I tried to explain one specific aspect of that (I want to verify the GPS position that my FC is using before I launch). Your comment quoted above, while a very effective insult, offers no substantiation, and lacks any substance other than the insult itself. Therefore, I would like to pick your brain a little to learn from my stupidity.

First of all, what specifically was crap? I assume to be considered crap, my comments have to at the very least be known by you to be wrong. What points of theory or understanding of the FC operation was I wrong on? I should specify I'm not asking about the phone displaying a temporarily incorrect GPS position. The occasional and unpredictable occurrence of this I know to be fact and I don't need your particular input or assumptive opinion on it. I used my iPhone 5s (always kept updated to the latest version of iOS) 3 or 4 times a week all last summer with a GPS tracking program for recording outdoor runs. I experienced this initially incorrect GPS position at least twice over the summer, and once about two weeks ago. I will attribute your comment about my phone to simple ignorance, and the human nature of assumption.

As I have experienced it and I know this situation can occur in a smartphone's GPS system, I gave it some credibility when I saw a youtube video ( took me forever to find it again, but here it is: https://www.youtube.com/watch?v=_ge3GuhEDRM ) in which someone else indicated they had experienced it, and they speculated about it happening in MR GPS systems, and how the FC would respond to initially incorrect, then changing GPS position data if this happened during the critical time when the FC is setting the HP. It was suspected that some people may have experienced what they thought were uncontrolled flyaways, when for a misunderstood reason, the FC was responding with proper control for the given data being fed to it. As it appears you have reasonable analytical troubleshooting skills, I assume you know sometimes what we assume is correct is not, and likewise, sometimes what we assume is incorrect may be totally correct, we just don't see why yet.

As I said before, this is all speculation, but trying to troubleshoot it is where the Flytrex Live 3G comes in. The Flytrex Live 3G can be used as a tool to verify that your MR FC correctly sees the GPS location of your MR. Unless you were to catch this false location condition actually happening to the GPS system on your MR, if that's even possible, you won't be able to prove that it's causing any flyaway conditions. However, you will be able to start each launch knowing the flight will NOT be affected an incorrect HP in memory. That's worth something to me. There are just too many unexplained flyaways of these MR aircrafts for me not to feel it's worthwhile to try and prove a possible cause, or at least eliminate the suspicion of a cause for my flights when I have the tools to do so. The Flytrex Live 3G is that tool.

I would appreciate being corrected on all of my incorrect understandings of how the FC would respond to the given scenarios I mentioned, even though you know the scenarios could never exist. It can be painful, but I'd rather learn from my stupidity than perpetuate it to others reading it.

Note to the Moderators: While this has a basic relevance to the Flytrex Live 3G Review thread, I realize this reply can be seen as moving from the original thread's topic. If it would be better to move the reply to a new thread, I understand.

Simply put the vPlus uses time based code. It's not going to not find a gps signal, and in turn just go with yesterdays data so it can proceed. It will stop, hover, and if nothing is received after X amount of time depending on the user settings, it will either land at it's location, or return to Home Point.

And from my own experience, if the gps becomes confused to the point of not knowing where it is, it will descend to the ground instantly. It won't fly off with one set command as you suggest. It's impossible, but let's say it does get sent a command as in a point to fly to. How do you think it will reach that point, or even attempt it if there is no gps to fly by to tell it it's location? It won't, it will do as I mentioned above. That's why this is a waste of time.

 

[amitregev]

Let me add that last night when I looked over the flytrex flight logger .csv file from my last flight, right at the point where I lifted at full throttle, the volts dropped a 1/2 volt, and the satellite switched from 6 to 7 at that same point & time. And prior to the launch the elevation/altitude will show some -2 -1, but at throttle up it goes right to "0". ****...the more I start to think about this now it very well could be a corrupt ground system. So here is when adding a inline diode would clean it up. A diode is like a check valve, it allows the current to flow in one direction but not the other. Some devices allow current (power) to bleed into it's own ground which then corrupts the ground system it's attached to. Then some, if not several other things in the system get confused, sensors can display the wrong reading and so on. This deal is not as bad as it sounds because no devices are grounded to any metal. When what I described above takes place with a metal ground is involved would be when things are much more effected. This is not one of those cases, so IF what I described is indeed into play, it's not that serious. Ok enough..I need to stop rambling.

To be honest, everything you described here makes perfect sense -- I'm not sure which part you consider as a problem.

Pushing the throttle means the engines were started and are now at higher power, this means the engines now draw more power form the lipo, which will lead to a certain drop in voltage. This is how every electronics system works -- when you draw more current you'll see the voltage dropping, up to a certain amount. This part that you describe makes perfect sense and has nothing to do with Flytrex. Any electronic circuit will behave this way - Flytrex is only logging this and visualize this behavior, so you get to see how it looks like.

In the same manner, after landing and shutting down the engines, you'll most likely see the voltage increasing a bit again, since the engines are no longer working. Again, you can easily see this with each and every flight graph.

If you ever had the chance to fly the Phantom and pushing the engines hard you probably noticed that you'd get the red LED indicating low battery. Then, if you'd go slightly more gentle on the throttle you'd notice that the LED stops blinking red. This is as a result of the exact same behavior - the voltage went slightly higher and above the minimum threshold and therefore the red LED blinking would stop, even though you never landed or charged the battery. You'd see this behavior whether or not your flying with Flytrex of course.

Regarding satellites count when lifting of the ground - GPS reception improves dramatically as you gain initial altitude. Again, this has nothing to do with Flytrex. This is how GPS systems work and we only give you the visualize to confirm this behavior. It is only reasonable that you'll have 6-7 satellites lock on the ground and it will increase to 10, 11 or 12 as you gain altitude from ground. There is much less objects to interfere reception as you gain altitude.

Regarding the ascent on Flytrex showing -2, -1 or 0 feet, that's all within the reasonable accuracy of altitude reading. Flytrex actually doesn't rely on GPS altitude buy uses its own built-in barometer. The reason is that GPS altitude isn't accurate and can have an error range of up to 10 meters in some cases. This is why all systems (Flytrex, the DJI Naza, APM and so on..) will use a barometer for altitude. With the barometer we reach approx ±1 meter accuracy. This means -2 feet and 0 feet are reasonable error levels and are still relatively accurate.

I can only assume you started to gain altitude when pushing the throttle, so it makes sense that you'll see altitude changing from -2 feet to 0 and growing. Again, let me know if you believe I missed anything.

You mentioned that you suspect the GPS reception decreases due to the drop in voltage. I'm sorry, this is simply not related to anything. Here is the link to Ublox GPS hardware integration datasheet (all 86 pages of it..). Ublox is a (very) serious company, and they know their way about their hardware and modules. I don't believe you'll find anything like this mentioned in this document: http://www.u-blox.com/images/downloads/ ... 007%29.pdf

Furthermore, the actual voltage on your aircraft main distribution board (where you'd connect the Flytrex Live) is MUCH higher than the voltage that the GPS is connected to. The GPS works somewhere between 5 to 3.3v, the main board with the engines is somewhere between 4S LiPo (±14.5v), so any drop from 14.5 to 14.0 isn't even affecting the voltage that gets to the GPS. The voltage that goes to the GPS (as well as to the entire flight controller is system) is regulated before, so this voltage is 100% stabilized.

Let me know if you believe I misunderstood you, or any of these specific points, and I'll be glad to try and provide more feedback.

 

[DrJoe]

I think Franks' biggest concern is that with the Flytrex harness, he gets a lower amount of satellites. As I have said, tucking the harness under my "foil mod" on the top shell of the Phantom eliminated that issue.

For those without the mod that find low satellites, perhaps wrapping the harness in foil tape would be helpful, or using ferrite donuts. I don't know, I didn't have to go any further than I did.

Love the Flytrex 3G, Amit.

 

[flyNfrank]

Regarding satellites count when lifting of the ground - GPS reception improves dramatically as you gain initial altitude. Again, this has nothing to do with Flytrex. This is how GPS systems work and we only give you the visualize to confirm this behavior. It is only reasonable that you'll have 6-7 satellites lock on the ground and it will increase to 10, 11 or 12 as you gain altitude from ground. There is much less objects to interfere reception as you gain altitude.

I'm aware of this and understand it well. However, I never once have made any reference to altitude. All of what I have went into has been directed at the quad before it leaves the launch point. And actually I think you are a little confused. Based on you saying a few times it has nothing to do with Flytrex, makes me think you are defending Flytrex when nobody is blaming it. My speculation has been about what is happening to the Flytrex rather then what the Flytrex is or is not doing. If something is not up to par with Flytrex I'm sure you would like to hear about it. This device is the only one there is that is 100% tailored around our hobby. And if the Live 3G can be tweaked here & there to function better, then so be it.

Regarding the ascent on Flytrex showing -2, -1 or 0 feet, that's all within the reasonable accuracy of altitude reading. Flytrex actually doesn't rely on GPS altitude buy uses its own built-in barometer. The reason is that GPS altitude isn't accurate and can have an error range of up to 10 meters in some cases. This is why all systems (Flytrex, the DJI Naza, APM and so on..) will use a barometer for altitude. With the barometer we reach approx ±1 meter accuracy. This means -2 feet and 0 feet are reasonable error levels and are still relatively accurate.

I can only assume you started to gain altitude when pushing the throttle, so it makes sense that you'll see altitude changing from -2 feet to 0 and growing. Again, let me know if you believe I missed anything.

First of all, I'm so glad you mentioned this as it reminds of something I wanted to ask you about. And that is, will you please add a column to the .csv file named "vertical ascent"? I know this particular function is configured in some of the dashware flytrex gauges, but with it displayed in it's own column will be a huge benefit when researching the quads behavior during top speed flights. And with some climbing altitude when against the wind.

As for your input above. You may have not seen where I explained I use 2 separate Flight Loggers. The Flytrex and another setup that uses the internal data of the vPlus. This one displays accurate elevation, and it doesn't take as long in milliseconds between each reading, which is important with top speed results. If the elevation issue could be resolved I wouldn't use this second one.

Furthermore, the actual voltage on your aircraft main distribution board (where you'd connect the Flytrex Live) is MUCH higher than the voltage that the GPS is connected to. The GPS works somewhere between 5 to 3.3v, the main board with the engines is somewhere between 4S LiPo (±14.5v), so any drop from 14.5 to 14.0 isn't even affecting the voltage that gets to the GPS. The voltage that goes to the GPS (as well as to the entire flight controller is system) is regulated before, so this voltage is 100% stabilized.

Let me know if you believe I misunderstood you, or any of these specific points, and I'll be glad to try and provide more feedback.

Actually I'm pretty sure you have misunderstood the main part I have focused most of my attention to. It's the Flytrex Wiring Harness that is contributing to everything that is currently going on. Its either one of two scenarios taking place. The harness alone is either causing the signal to be delayed from the GPS to the board, or there is something going on in the ground system by corrupting the resistance being read at the board.

-So I guess if I were going to investigate this further, I would 1st make 3 short flights rebooting everything and to look for any inconsistencies between them.The elevation would have my most attention, then amount of satellites.
-I would then disconnect the Live 3G, and unplug the harness, and plug GPS back in stock plug. Make a couple small flights and note same areas of interest.
-Then compare results and begin adjustments.

I looked at the .csv file on some of my flights and my elevation was off by 18ft, 30ft, 40ft on the 3 files I looked at. The attached image is off by 18ft. on elevation. Also image shows point of throttle up to begin flight.

 

[Chuck26287]

Simply put the vPlus uses time based code. It's not going to not find a gps signal, and in turn just go with yesterdays data so it can proceed. It will stop, hover, and if nothing is received after X amount of time depending on the user settings, it will either land at it's location, or return to Home Point.

And from my own experience, if the gps becomes confused to the point of not knowing where it is, it will descend to the ground instantly. It won't fly off with one set command as you suggest. It's impossible, but let's say it does get sent a command as in a point to fly to. How do you think it will reach that point, or even attempt it if there is no gps to fly by to tell it it's location? It won't, it will do as I mentioned above. That's why this is a waste of time.

I agree with everything you are saying here, Frank, but it's not what I was theorizing on. You seem to be talking about the GPS in a state where it can "not find a GPS signal", or where "the GPS becomes confused to the point of not knowing where it is". Given the scenario you are describing, I wouldn't indicate the MR would respond like I did in my earler post. How could it? Even I know when the FC cannot determine a current location from the GPS system, it can't calculate directions to fly to a GPS location, RTH or otherwise. You can't go from "A" to "B" if you don't know what "A" is. I've looked over my comments, and the indicated video, and no where am I, or the guy in the video, discussing a GPS in the state you are talking about. There is a difference between a scenario where the GPS has no signal or is not providing location data because it does not know where it is, and a scenario where the GPS is operating normally, but intially provides inaccurate/less precise position data, the FC sets the HP to this inaccurate position, then the GPS adjust the data it provides as it operates to reflect more accurate/precise position data. In this scenario you have a HP set to some location other than where you actually launched from. I have yet to see anything that makes me think the FC would not respond as I stated based on the scenario I actually presented. You're right... this is a waste of time.

This whole discussion started because I saw a guy's video who wondered if a condition that is indeed present in smartphone GPS usage (you start your phone's GPS app, and initially your position shown is inaccurate, then after some time and/or movement, the position updates to an accurate position) could be present in our MR GPS systems, sometimes causing "flyaways". Like him, I thought if something like this could happen in a smartphone's GPS system, why couldn't it possibly be happening in our MR GPS system? I thought the Flytrex Live 3G would be a good tool to investigate it with.

I have since done some research, and I no longer feel it's valid to think what can happen in our phone GPS could happen in our MR GPS. On a phone, the innacurate position plot usually occurs at the start of using the GPS app. Come to find out, it appears a smartphone is often not using only a GPS system to plot that position you are looking at. It is often times a plot generated by using multiple "location services" sources, which includes not just GPS, but cell tower triangulation, Wi-Fi systems, and other methods of location calculation available right then. In some GPS apps, if it can't get a quick calculation from the GPS, it will plot a location based on the other info sources it can utilize right then. It appears this is why the initial plot can be off by a fair distance, as these other sources are not nearly as accurate as the GPS. When the GPS does stabilize and starts providing useful data to the app, it's much more accurate and the app updates to displaying the more accurate position plot. This sometimes involves the plot jumping from the less accurate position display, to the new more accurate display plot. With the exception of altitude being determined by barometric pressure sensor data on our MR systems, I'm not aware of anything other than the GPS system being used to determine location for the MR. Therefore, I can't see the condition that can happen on our phones being something that can happen on or MR GPS system. If I had known before what can cause this condition on our phones, I would have never even started the conversation.

As a note, I tried to use multiple sources, but this is learned info from internet research. Often correct and useful, but sometimes logical sounding, and entirely wrong. If someone sees I'm wrong, please tell me. I only ask that you correct me by providing the correct info. I can handle being called stupid, I just like to get smarter as a result of it.

Now if you will excuse me, I need to go update my phone to get rid of this problem.

 

[amitregev]

Regarding satellites count when lifting of the ground - GPS reception improves dramatically as you gain initial altitude. Again, this has nothing to do with Flytrex. This is how GPS systems work and we only give you the visualize to confirm this behavior. It is only reasonable that you'll have 6-7 satellites lock on the ground and it will increase to 10, 11 or 12 as you gain altitude from ground. There is much less objects to interfere reception as you gain altitude.

I'm aware of this and understand it well. However, I never once have made any reference to altitude. All of what I have went into has been directed at the quad before it leaves the launch point. And actually I think you are a little confused. Based on you saying a few times it has nothing to do with Flytrex, makes me think you are defending Flytrex when nobody is blaming it. My speculation has been about what is happening to the Flytrex rather then what the Flytrex is or is not doing. If something is not up to par with Flytrex I'm sure you would like to hear about it. This device is the only one there is that is 100% tailored around our hobby. And if the Live 3G can be tweaked here & there to function better, then so be it.

Regarding the ascent on Flytrex showing -2, -1 or 0 feet, that's all within the reasonable accuracy of altitude reading. Flytrex actually doesn't rely on GPS altitude buy uses its own built-in barometer. The reason is that GPS altitude isn't accurate and can have an error range of up to 10 meters in some cases. This is why all systems (Flytrex, the DJI Naza, APM and so on..) will use a barometer for altitude. With the barometer we reach approx ±1 meter accuracy. This means -2 feet and 0 feet are reasonable error levels and are still relatively accurate.

I can only assume you started to gain altitude when pushing the throttle, so it makes sense that you'll see altitude changing from -2 feet to 0 and growing. Again, let me know if you believe I missed anything.

First of all, I'm so glad you mentioned this as it reminds of something I wanted to ask you about. And that is, will you please add a column to the .csv file named "vertical ascent"? I know this particular function is configured in some of the dashware flytrex gauges, but with it displayed in it's own column will be a huge benefit when researching the quads behavior during top speed flights. And with some climbing altitude when against the wind.

As for your input above. You may have not seen where I explained I use 2 separate Flight Loggers. The Flytrex and another setup that uses the internal data of the vPlus. This one displays accurate elevation, and it doesn't take as long in milliseconds between each reading, which is important with top speed results. If the elevation issue could be resolved I wouldn't use this second one.

Furthermore, the actual voltage on your aircraft main distribution board (where you'd connect the Flytrex Live) is MUCH higher than the voltage that the GPS is connected to. The GPS works somewhere between 5 to 3.3v, the main board with the engines is somewhere between 4S LiPo (±14.5v), so any drop from 14.5 to 14.0 isn't even affecting the voltage that gets to the GPS. The voltage that goes to the GPS (as well as to the entire flight controller is system) is regulated before, so this voltage is 100% stabilized.

Let me know if you believe I misunderstood you, or any of these specific points, and I'll be glad to try and provide more feedback.

Actually I'm pretty sure you have misunderstood the main part I have focused most of my attention to. It's the Flytrex Wiring Harness that is contributing to everything that is currently going on. Its either one of two scenarios taking place. The harness alone is either causing the signal to be delayed from the GPS to the board, or there is something going on in the ground system by corrupting the resistance being read at the board.

-So I guess if I were going to investigate this further, I would 1st make 3 short flights rebooting everything and to look for any inconsistencies between them.The elevation would have my most attention, then amount of satellites.
-I would then disconnect the Live 3G, and unplug the harness, and plug GPS back in stock plug. Make a couple small flights and note same areas of interest.
-Then compare results and begin adjustments.

I looked at the .csv file on some of my flights and my elevation was off by 18ft, 30ft, 40ft on the 3 files I looked at. The attached image is off by 18ft. on elevation. Also image shows point of throttle up to begin flight.

Hi Frank,

Thanks for the feedback! First, regarding the feature request for ascent column, please note one column to the right of the altitude, titled Ascent (also included in the screen shot you provided), this includes the aircraft ascent at any given time from the ground. If I understand correctly this is the column you were looking for. Let me know if any specific information here is missing.

Regarding the altitude offset, if I understand correctly, this isn't something that I can actually see in the attached CSV screen capture you included? Assuming I understand the situation, you compared the altitude reading from Flytrex with the data stored in the second flight logger and you are noticing this offset in flight altitude between the two, is that the case?

Looking forward for your feedback and I'll be glad to explain some more what might be causing this.

Thanks!