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Jan 11, 2017, 11:25 AM
Just another user
Dennis Frie's Avatar
Quote:
Originally Posted by jellyfish
This cannot be enabled while Radio Modem is selected for BT.
i guess i need to connect, change settings, save, reboot, do my stuff, then connect to GUI Config again, change settings, save, reboot.

Correct?
Indeed, having 2 serial outputs and 2 serial-inputs both with the same "destination" would be a bit of a mess. I don't quite see the need for using both at the same time. If you use bluetooth, you can do "all your stuff" using that?
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Jan 11, 2017, 11:30 AM
Registered User
Quote:
Originally Posted by Dennis Frie
Indeed, having 2 serial outputs and 2 serial-inputs both with the same "destination" would be a bit of a mess. I don't quite see the need for using both at the same time. If you use bluetooth, you can do "all your stuff" using that?
I don't need both at the same time - i need to alternate between the two and I still don't think i understand how to do this without changing so many settings in between.
Jan 11, 2017, 12:08 PM
JettPilot's Avatar
DRAGON LINK SHIPPING STATUS

We have the new Dragon Link V3 Advanced Slim Systems in stock, including the new Large 1500 mW telemetry receivers. We are totally caught up from the holidays and all orders are shipping within 24 hours

New for 2017, the store software will only sell items that are in stock and are ready to ship, so no more waits on shipping ever. Out of stock items will be clearly labeled as out of stock, and there will be no " buy " button. If the store shows an item in stock, and will let you buy it, it will ship immediately !

Mike
Jan 11, 2017, 12:57 PM
Registered User
Quote:
Originally Posted by jellyfish
I don't need both at the same time - i need to alternate between the two and I still don't think i understand how to do this without changing so many settings in between.
I don't understand why you need to swap. Is it because you don't have a bluetooth dongle for your PC?
Jan 11, 2017, 01:02 PM
Registered User
Quote:
Originally Posted by Noircogi
I don't understand why you need to swap. Is it because you don't have a bluetooth dongle for your PC?
Correct.
I was trying to connect to PC using it's built-in BT (paring successful) but for some reason connection to MP fails.
BT Connection to Tower however works great.
Jan 11, 2017, 01:08 PM
Registered User
I use bluetooth to multiple PCs with mission planner no problem. I believe there may be an issue in some recent mission planner builds (I've heard). I'm still using an older version which works fine. I'm at work now so can't give version info unfortunately.

If that's the problem, I don't think bluetooth versus direct serial link will make any difference.
Jan 11, 2017, 01:24 PM
Registered User
Quote:
Originally Posted by Noircogi
I use bluetooth to multiple PCs with mission planner no problem. I believe there may be an issue in some recent mission planner builds (I've heard). I'm still using an older version which works fine. I'm at work now so can't give version info unfortunately.

If that's the problem, I don't think bluetooth versus direct serial link will make any difference.
Thank you.
If there was a simple menu to switch back and forth between BT and USB that would have saved the day.
Once you have it, Please share your version of MP that works with BT.

I am still puzzled how Towers works just great with both BT and USB and MP have issues - either wont connect to BT, or with USB Radio Modem downloading parameters can take some time, unlike with Tower (using same 3DR radio..)
Jan 11, 2017, 01:32 PM
Registered User
That's easy to explain. The dragonlink telemetry link has different bandwidth up and down.
It also has no end-to-end flow control.
My recipe for making that work with mission planner is all about tuning the downstream link to never overrun.

The up-stream link is not limited in that way and can easily overrun. If the mission planner code transmits a large burst of info before waiting for a response, the pixhawk will see a corrupted data stream and may not recover properly.
Jan 12, 2017, 04:43 AM
JettPilot's Avatar
Quote:
Originally Posted by Noircogi
That's easy to explain. The dragonlink telemetry link has different bandwidth up and down.
It also has no end-to-end flow control.
My recipe for making that work with mission planner is all about tuning the downstream link to never overrun.

The up-stream link is not limited in that way and can easily overrun. If the mission planner code transmits a large burst of info before waiting for a response, the pixhawk will see a corrupted data stream and may not recover properly.
Hi Noircogi,

Thanks for explaining this in a way that everyone can understand. For now, we have to use high data rates to assure there is no data corruption which limits range.... I wish Mavlink was more efficient in bandwidth, but we might get old waiting for them to fix that Dennis has actually been working this and has a solution to fix this Mavlink functionality will be amazing in the next firmware update !

Mike
Jan 12, 2017, 06:43 AM
Registered User
Hello need some help

currently i am busy making a DIY rover for my senior year project.
it consists of using a arduino to translate my ps4 controler signals into ppm. This process i have programed and gets transmitted just fine.

My issue is on the other end of the reciever i currently have the reciever configured to have all channels as pwm. Wen looking at the 3 diffrent pwm signals on the seperate channels they are correct. but wen i connect one of my larger servos to any of these channels the other channels start getting terrible interference , this causing my micro servo on my 3D printed gimbal to sudenly start turning 360 degrees. I also get a spike on the power source of the reciever.

anybody have any thoughts where my problem might be
Jan 12, 2017, 07:29 AM
Just another user
Dennis Frie's Avatar
Quote:
Originally Posted by JettPilot
Hi Noircogi,

Thanks for explaining this in a way that everyone can understand. For now, we have to use high data rates to assure there is no data corruption which limits range.... I wish Mavlink was more efficient in bandwidth, but we might get old waiting for them to fix that Dennis has actually been working this and has a solution to fix this Mavlink functionality will be amazing in the next firmware update !

Mike
Well, the MavLink decoding as have been discussed will indeed help with basic downlink, but for full MavLink functionality it will be the same
Jan 12, 2017, 07:32 AM
Just another user
Dennis Frie's Avatar
Quote:
Originally Posted by RedDwarfCruz
Hello need some help

currently i am busy making a DIY rover for my senior year project.
it consists of using a arduino to translate my ps4 controler signals into ppm. This process i have programed and gets transmitted just fine.

My issue is on the other end of the reciever i currently have the reciever configured to have all channels as pwm. Wen looking at the 3 diffrent pwm signals on the seperate channels they are correct. but wen i connect one of my larger servos to any of these channels the other channels start getting terrible interference , this causing my micro servo on my 3D printed gimbal to sudenly start turning 360 degrees. I also get a spike on the power source of the reciever.

anybody have any thoughts where my problem might be
By any chance you have a scope? I would like to see the supply-voltage measured directly on the servo-pins when you move the large servo. That should be the place to start.

Measuring the PWM-output on the channel affected would be interesting too and if you have a more fancy oscilloscope, a duty-cycle graph of the channel with noise would be interesting too

Edit: Another simple test is to power the MicroRx from USB at the same time. That will ensure stable supply to the MicroRx to see, if it's a problem related to the power
Last edited by Dennis Frie; Jan 12, 2017 at 07:44 AM.
Jan 12, 2017, 08:04 AM
Registered User
Quote:
Originally Posted by Dennis Frie
By any chance you have a scope? I would like to see the supply-voltage measured directly on the servo-pins when you move the large servo. That should be the place to start.

Measuring the PWM-output on the channel affected would be interesting too and if you have a more fancy oscilloscope, a duty-cycle graph of the channel with noise would be interesting too
Yes i do have sevral scopes a cheap rigol and a large 3 grand Tektronix, i wil see if its posible for me to make a duty-cycle graph with the Tektronix, if im not able to do it today i will next week thursday

for now i can tell you the last time i measured i recal seeing a dip right before the rising flank and sevral recurring quick rises that where large enough to be registerd by the servos. simultaneously the surge on the powersource apears. also the noise isnt just one channel but every one with a pwm yet every one is affected slighlt difrently. but i cant say anything for sertain since these are my recolections from a month ago.

also today wen connecting the larger steering servo and the horizonatal servo of the gimbal the leds on the reciever will suddenly turn off but im still getting signal.
Jan 12, 2017, 08:52 AM
Just another user
Dennis Frie's Avatar
Quote:
Originally Posted by RedDwarfCruz
Yes i do have sevral scopes a cheap rigol and a large 3 grand Tektronix, i wil see if its posible for me to make a duty-cycle graph with the Tektronix, if im not able to do it today i will next week thursday

for now i can tell you the last time i measured i recal seeing a dip right before the rising flank and sevral recurring quick rises that where large enough to be registerd by the servos. simultaneously the surge on the powersource apears. also the noise isnt just one channel but every one with a pwm yet every one is affected slighlt difrently. but i cant say anything for sertain since these are my recolections from a month ago.

also today wen connecting the larger steering servo and the horizonatal servo of the gimbal the leds on the reciever will suddenly turn off but im still getting signal.
It sure sounds like a power-surge. My best guess is, simply measuring the supply-voltage will tell a lot. If you see small spikes etc. no need to look more into duty-cycle etc.
I would suggest to: Power by USB too to test for brown-out, add a bulk-capacitor or better BEC or change the servo. If you measure the current-draw from the servo, I have a feeling it's drawing some serious spikes the BEC can't handle.
Jan 12, 2017, 11:29 AM
Registered User
Quote:
Originally Posted by Dennis Frie
It sure sounds like a power-surge. My best guess is, simply measuring the supply-voltage will tell a lot. If you see small spikes etc. no need to look more into duty-cycle etc.
I would suggest to: Power by USB too to test for brown-out, add a bulk-capacitor or better BEC or change the servo. If you measure the current-draw from the servo, I have a feeling it's drawing some serious spikes the BEC can't handle.
I measured more indepth with the beter scope, and the channel with the noise is channel 6. If nothing is connected at all or i have one of my servos only connected on channel 6 the signal is fine. the moment i connect another channel ( in my case chan 8) without anything on chan 6. i get what you can see in the picture "chan 6 not connected". And than if i connect the servo to 6 and i measured what you see in the picture connected.

its in this case that all the leds turn off but i dont lose signal


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