The Mobius 1 ActionCam Support Thread (Posts #1-#7 mandatory reading!) - Page 1373 - RC Groups
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Nov 08, 2017, 09:49 PM
Dance the skies...
Tom Frank's Avatar
Quote:
Originally Posted by mutski
Can I pull the battery from my Mobius and connect straight to the 5V power output from a UBEC? That is, plug a 5V connection into the connection where the battery should be plugged in? i.e. bypass the USB port

OK, I found the answer on Youtube. Yes, I can.
https://www.youtube.com/watch?v=XtqgCfgjb14
https://www.youtube.com/watch?v=tJUCtBowBYw&t=115s

I was worried because the battery is 3.7 v; is 5v through the USB connector cut down before it reaches the camera? But apparently people have done this.
Can you do it, sure, you could, but should you do it? NO! Do not feed 5V power to the cameras battery connection terminal unless you want to stress the camera into an early demise!

The battery will be at a nominal 4.2V max when it is fully charged, and I would NOT put a greater voltage than that on the battery terminals. That video showed stepping down flight battery voltage to a nominal 4.7V, which is still too high for the long term health of the camera. I don't see how you determined from that it was OK to go even higher with a 5V input onto the camera battery terminals.

FWIW, the USB 5V source is dropped down in the camera circuit to feed the battery charging circuit, which is limited to 4.2V max. for the internal battery. You could, though, connect the 5V source to the USB port and leave the battery out. The camera will still operate OK with 5V USB power without a battery, but the internal clock will stop and reset to the default date and time every time the camera is booted that way.
Last edited by Tom Frank; Nov 08, 2017 at 09:52 PM. Reason: clearer.
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Nov 08, 2017, 11:08 PM
mutski
Quote:
Originally Posted by Tom Frank
Can you do it, sure, you could, but should you do it? NO! Do not feed 5V power to the cameras battery connection terminal unless you want to stress the camera into an early demise!

The battery will be at a nominal 4.2V max when it is fully charged, and I would NOT put a greater voltage than that on the battery terminals. That video showed stepping down flight battery voltage to a nominal 4.7V, which is still too high for the long term health of the camera. I don't see how you determined from that it was OK to go even higher with a 5V input onto the camera battery terminals.

FWIW, the USB 5V source is dropped down in the camera circuit to feed the battery charging circuit, which is limited to 4.2V max. for the internal battery. You could, though, connect the 5V source to the USB port and leave the battery out. The camera will still operate OK with 5V USB power without a battery, but the internal clock will stop and reset to the default date and time every time the camera is booted that way.
Thanks for the better info Tom. I will change my plan. My onboard camera is still failing in the cold. I'm not sure if it's the cold and the wind, or the battery failing. I was going to hook it to the flight battery. I'll do it through the USB connection instead.
Nov 08, 2017, 11:11 PM
Keep Looking Up
BWX232's Avatar
Probably both. Cold affects lipos, but worn lipos will be more affected.
Nov 09, 2017, 05:21 AM
animator in Helsinki, Finland
Quote:
Originally Posted by mutski
Thanks for the better info Tom. I will change my plan. My onboard camera is still failing in the cold. I'm not sure if it's the cold and the wind, or the battery failing. I was going to hook it to the flight battery. I'll do it through the USB connection instead.
You could do it, by having two diodes in series with your 5 volt line!

For instance, a 1N400X-series diode will lower the voltage by approx. 0.7 volts, two in series by 1.4 volts ( X = any digit from 1 to 7).

5 volts minus 1.4 volts = 3.6 volts, very close to the nominal battery voltage of 3.7 volts.

(Re. the video: Provided that the regulator which is shrink-wrapped together with the camera is adjusted to provide 3.7 volts, it's a working solution!)
Nov 09, 2017, 06:44 PM
Dance the skies...
Tom Frank's Avatar
Quote:
Originally Posted by Janke
You could do it, by having two diodes in series with your 5 volt line!

For instance, a 1N400X-series diode will lower the voltage by approx. 0.7 volts, two in series by 1.4 volts ( X = any digit from 1 to 7).

5 volts minus 1.4 volts = 3.6 volts, very close to the nominal battery voltage of 3.7 volts.

(Re. the video: Provided that the regulator which is shrink-wrapped together with the camera is adjusted to provide 3.7 volts, it's a working solution!)
I had consider something like this, but the BEC output, especially under load can vary a bit, and lowering the voltage to 3.6V is right on the cusp of where the camera will shut down from low voltage on the battery terminals, unfortunately. A single diode dropping 5V to 4.3V MIGHT be possible and not over stress the camera circuitry so much if the BEC output is reasonably accurate and stable, and not also powering something else. I should have also mentioned that USB external power input is recommended to be rated for at least 1A, though with no battery in the camera to charge, perhaps this is overly conservative for reliable camera operation. I'd do some BEC output power checking for sure before proceeding either way.
Nov 10, 2017, 03:36 AM
animator in Helsinki, Finland
I have used these "buck" converters for many projects:

https://www.ebay.com/itm/292297090822

They are adjustable, and can thus provide an exact 3.7 volts for the camera.

However, there is one limitation: The input voltage needs to be at least two or three volts higher than the output, so they won't work with a 3.7 volt quad battery or a 5 volt BEC.

A quad battery of 7.4 volts or higher (max 28 volts) is OK. The converter is specced at 3 amps max, quite enough even for two cameras.

Edit: Below is a photo of my UDI 818 quad, with a Mobius 1 camera attached right on top of the quad's circuit board. Both the quad and the camera have been stripped to the bare essentials! I do use a BEC providing 5 volts into the USB of the camera, not the buck converter mentioned above. (The quad is standing on my model railroad track, of a slightly larger than normal size - the train is 20 ft long, and the locomotive weighs 400 lbs... )

Thanks to the placement of the camera very close to the center of gravity, the image is pretty stable. Here's an example:

555 (0 min 32 sec)


(No, that's not my model, but a full-sized prototype for it, in the Finnish Railway Museum ! )
Last edited by Janke; Nov 10, 2017 at 04:37 AM.
Nov 10, 2017, 04:24 AM
Fidler & twidler
empeabee's Avatar
Quote:
Originally Posted by Janke
I have used these "buck" converters for many projects:

https://www.ebay.com/itm/292297090822

They are adjustable, and can thus provide an exact 3.7 volts for the camera.

However, there is one limitation: The input voltage needs to be at least two or three volts higher than the output, so they won't work with a 3.7 volt quad battery or a 5 volt BEC.

A quad battery of 7.4 volts or higher (max 28 volts) is OK. The converter is specced at 3 amps max, quite enough even for two cameras.
Being an Oldy Mouldy, I'm obviously not up to date - what is a Quad Battery please - I've not heard of that before.
Mike
Nov 10, 2017, 04:30 AM
animator in Helsinki, Finland
Quote:
Originally Posted by empeabee
Being an Oldy Mouldy, I'm obviously not up to date - what is a Quad Battery please - I've not heard of that before.
Mike
It's the battery powering your quad = quadcopter...

See the photo in my edit in the post above yours.
Nov 10, 2017, 06:55 AM
Fidler & twidler
empeabee's Avatar
Quote:
Originally Posted by Janke
It's the battery powering your quad = quadcopter...

See the photo in my edit in the post above yours.
!DUH! and here's me thinking 'twas a new batter chemistry that got by me ... !/DUH!
Nov 16, 2017, 03:10 PM
Registered User
TheLeabres's Avatar
Help! Thanks for any advice, suggestion, solution.
Two Mobius Cameras Same Settings Different Image Quality - Why? (0 min 45 sec)
Nov 16, 2017, 03:43 PM
Dance the skies...
Tom Frank's Avatar
Quote:
Originally Posted by TheLeabres
Help! Thanks for any advice, suggestion, solution.
https://www.youtube.com/watch?v=y5_sgDztVDk
There's two things that can cause this either singly or together. First, do the cameras have the same lenses in them? The shots of the plane shows both cameras have the lens that fits totally inside the case (Lens A), but the image on the left looks to have a wider FOV. This could be due to the FW toggled to Wide FOV for the camera on the left, and Narrow for the camera on the right. Check to see that both are set to the same FOV in the Video Mode. That alone won't cause a white balance problem like you have, but it could rule out different lens characteristics.

Then open the Basic Settings Tab in the mSetup GUI and check to see that both cameras are configured for the same Lens Type. If they are and you still get this wide variation in the WB, the lenses must not be identical in their optical properties. You can try to correct this in the FW by choosing a different lens type setting, or in the Color Options setting (try warmer settings to cancel the blue tint). Finally, you can also set up your own fixed WB setting by adjusting the Red, Green, and Blue components until they give the desired results. This would prevent having an auto WB function, though, and is a bit difficult to tweak unless you are good at color mixing (much trial and error to get it right).
Nov 16, 2017, 04:36 PM
Registered User
TheLeabres's Avatar
Quote:
Originally Posted by Tom Frank
There's two things that can cause this either singly or together. First, do the cameras have the same lenses in them? The shots of the plane shows both cameras have the lens that fits totally inside the case (Lens A), but the image on the left looks to have a wider FOV. This could be due to the FW toggled to Wide FOV for the camera on the left, and Narrow for the camera on the right. Check to see that both are set to the same FOV in the Video Mode. That alone won't cause a white balance problem like you have, but it could rule out different lens characteristics.

Then open the Basic Settings Tab in the mSetup GUI and check to see that both cameras are configured for the same Lens Type. If they are and you still get this wide variation in the WB, the lenses must not be identical in their optical properties. You can try to correct this in the FW by choosing a different lens type setting, or in the Color Options setting (try warmer settings to cancel the blue tint). Finally, you can also set up your own fixed WB setting by adjusting the Red, Green, and Blue components until they give the desired results. This would prevent having an auto WB function, though, and is a bit difficult to tweak unless you are good at color mixing (much trial and error to get it right).
Okay, I will check the items you mentioned. Thanks very much. Great help.
Nov 16, 2017, 05:08 PM
Registered User
TheLeabres's Avatar
@ Tom Frank
Thanks for your expertise. You were right. One of the cameras had a different FOV setting. I made sure they were both at Narrow and then did a quick indoor test and the colors matched. You solved the problem!
Nov 16, 2017, 08:16 PM
Dance the skies...
Tom Frank's Avatar
Quote:
Originally Posted by TheLeabres
@ Tom Frank
Thanks for your expertise. You were right. One of the cameras had a different FOV setting. I made sure they were both at Narrow and then did a quick indoor test and the colors matched. You solved the problem!
Hmmm... I would not normally expect equalizing the FOV would change the WB enough to cause that strong blue tint in your video in the right camera. Check again outdoors in bright sun, but before that make sure both cameras have the same lens option set (e.g. "Lens A") in the FW if you have not already confirmed that. That can definitely make a big change like your video showed.

Post your final results if you don't mind.
Last edited by Tom Frank; Nov 16, 2017 at 08:18 PM. Reason: rephrased sentence.
Nov 17, 2017, 02:45 AM
Registered User
dirkzelf's Avatar
Quote:
Originally Posted by Tom Frank
Hmmm... I would not normally expect equalizing the FOV would change the WB enough to cause that strong blue tint in your video in the right camera. Check again outdoors in bright sun, but before that make sure both cameras have the same lens option set (e.g. "Lens A") in the FW if you have not already confirmed that. That can definitely make a big change like your video showed.

Post your final results if you don't mind.

It always happens with my 2 Mobī in twilight from day to evening.... I don't like it, but I've never really bothered to fix it, I'm not even sure it would be fixable.


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