Mid-air BT-300 system shut down 'USB CHARGER ERROR' - HELP!

[bmelody]

Hi Ken,

When I ran the experiment I was looking at the Ampere app display most of the time. I did have DJI going in the background but displaying the Ampere app. I also had my Mavic Pro sitting idle (no props) connected showing a video but I was not using a screen recorder. I'll bet running a screen recorder would really tax the BT's but that's for another experiment. At 12.5 I switched the display over to the DJI app and noticed an increase in demand. The reason I pointed this out is because it will effect the batt remaining column in my data. It would reduce the run time for the BT's. All that being said the BT's had enough battery left at the end of the experiment (62%) indicates I could have watched the DJI the whole time and still had power left over. But it is interesting how much power the GPU requires when processing video.

~Bill

 

[Ken Nash]

Thanks for your reply Bill and understand more now, that was most informative. Personally I would like a pair of BT's but I am reluctant in as much as I think they should upgrade the controller with better chip and CPU technology because I have read quite alot of negatives about these, I think considering DJI and Epson are billion dollar companies these glasses should be the first go-to FPV's.

 

[bmelody]

Totally agree Ken,

I found mine on Craig's list and got them for almost 1/2 price. Really nice guy that needed some money for taxes.

The CPU is barely adequate, just barely enough speed to run DJI Go but it does quite well. I never had a DJI GO crash or pixelation problem. I never had any issues until I started using an OTG cable. That's when the thing started to get hot. Prior I only flew with a Spark using WiFi and never had any issues.



1.44GHz and only a quad core. Nothing mentioned about the GPU possibly part of the CPU not sure but man oh man what a display. Once you try one you will have to have one. I am sure we will come up with a solution.

~Bill

 

[DVegaman]

I think I need a smaller fan

Did up a fan rig myself. Thanks for the inspiration. Need to clean up the print a bit.

 

[bmelody]

DVegaman,

I love the mounting method very clever. From the picture your fans appear to be the perfect size. What size are they?

I see you are using a different mount than mine but very similar. I went with a single fan and left the area above the fan open so to create an exhaust opening to allow for air flow. My concern with your design is there is no way for the hot air to escape. Perhaps you have a larger opening along the sides of the BT's that will allow for air flow. In my mount there are no openings when the BT's are in place.

I am thinking of closing up the opening above my fan by about 1/2 to force the air further up and then out. My mount had a cross web just like web between your fans. I removed the web to open up the area and allow the air from a single fan to flow up and out. In my case I am getting good air flow.

I wonder how much air flow increase you would get if you were to remove the web separating the chambers and flip one of your fans so one fan sucks and the other blows creating a nice wind tunnel over the entire back of the BT's? If you decide to try this idea please document the difference if possible.

How are you powering the fans?

Did you limit the charge current going to the BT's?

Looking forward to seeing your results.

~Bill

 

[DVegaman]

DVegaman,

I love the mounting method very clever. From the picture your fans appear to be the perfect size. What size are they?

I see you are using a different mount than mine but very similar. I went with a single fan and left the area above the fan open so to create an exhaust opening to allow for air flow. My concern with your design is there is no way for the hot air to escape. Perhaps you have a larger opening along the sides of the BT's that will allow for air flow. In my mount there are no openings when the BT's are in place.

I am thinking of closing up the opening above my fan by about 1/2 to force the air further up and then out. My mount had a cross web just like web between your fans. I removed the web to open up the area and allow the air from a single fan to flow up and out. In my case I am getting good air flow.

I wonder how much air flow increase you would get if you were to remove the web separating the chambers and flip one of your fans so one fan sucks and the other blows creating a nice wind tunnel over the entire back of the BT's? If you decide to try this idea please document the difference if possible.

How are you powering the fans?

Did you limit the charge current going to the BT's?

Looking forward to seeing your results.

~Bill

Bill,

Here is a link to the fans I am using. https://www.amazon.com/gp/product/B00ZDCCPUS/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 60mm. I didn't think to put vent holes on the side of the mount. Doing that now and will reprint. Thanks for your input. Will also try reversing one of the fans to see how it functions. (Won't be able to report back until after the holiday) I am powering the fans with a very small powerbank I zip tied to the underside of the mount. (Look at bottom right of first pic) I will keep you posted on the new config.

DV

 

[bmelody]

Looking forward to your test results.

Thanks for the link to the fans. The mini power pack is an excellent idea.

~Bill

 

[Davo_101]

Bill,

Here is a link to the fans I am using. https://www.amazon.com/gp/product/B00ZDCCPUS/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 60mm. I didn't think to put vent holes on the side of the mount. Doing that now and will reprint. Thanks for your input. Will also try reversing one of the fans to see how it functions. (Won't be able to report back until after the holiday) I am powering the fans with a very small powerbank I zip tied to the underside of the mount. (Look at bottom right of first pic) I will keep you posted on the new config.

DV

Great work @DVegaman - I love how this is evolving without any help from Epson, it would be great to have some comment from them through to help us along with this.

It sounds as if you are printing the mount yourself. If successful I am sure you could generate some orders. I'd be first in line to have something a bit more elegant for my rig.

Thanks again - David.

 

[DVegaman]

Looking forward to your test results.

Thanks for the link to the fans. The mini power pack is an excellent idea.

~Bill

Made a few speed holes.

 

[DVegaman]

Great work @DVegaman - I love how this is evolving without any help from Epson, it would be great to have some comment from them through to help us along with this.

It sounds as if you are printing the mount yourself. If successful I am sure you could generate some orders. I'd be first in line to have something a bit more elegant for my rig.

Thanks again - David.

Always glad to help out the Moverio Community.

 

[Davo_101]

I just realised that my mount has a solid back - so no ventilation from below. This could be a contributing factor to my heat retention. I am going to need another mount I think or my large fan will be mostly cooling the mount and not the Movs. It must be so cool to be able to make things like this yourself.

 

[DVegaman]

I just realised that my mount has a solid back - so no ventilation from below. This could be a contributing factor to my heat retention. I am going to need another mount I think or my large fan will be mostly cooling the mount and not the Movs. It must be so cool to be able to make things like this yourself.

I would be happy to help you out after I iron out a few of the ruff edges.

 

[chuck1026]

I wonder if a new back cover for the BT's made from aluminum would help dissipate the heat? Maybe just adding a simple heatsink to the back case would reduce the temperature enough to stop the shutdown and or USB Charger Error?
~Bill

Bill, Great thoughts!

I hope I don't jinx myself, but I haven't experienced this fault flying my Mavic Pro, Mavic Air or Spark using the Moverio BT-300's. When I read the concerns, I immediately wondered why we can't fab up a heat sink cover for the controller case which opens up easily (I wish I took pictures). Passive cooling with a heat sink would package nicely compared to the PC box fan setup.

Does anyone have a 3D printer that could use aluminum billet as material?

 

[bmelody]

Hi Chuck,

Thanks for the response. I think an aluminum back would solve most of the heat issues as well. I am going to check with my son-in-law to see if can help in any way. He is a mechanical design engineer at Intuitive Surgical. He designs robots that operate on people. He may have access a printer that can a least make a prototype.

I opened up the BT's. Got as far as getting the touch pad off but did not totally remove the case. Do you think we can gain access to the CPU and battery to make contact with an aluminum back using sill pads to get the maximum heat transfer?

I have some heatsinks and fans on order from Amazon to see if I can suck some heat out using a passive device.

Looks like DV has a 3D printer maybe he can make a new holder that incorporates a fan with a duct for the air to properly flow.

David, you need to open up the back of your holder. DO you know anyone with a mill? If you have access to a mill it would be very easy to open that back area up. Opening up the back is an absolute must on your do list.

With enough of us coming up with ideas we will get this to a level of confidence where we can trust in the BT's again.

Sure would be nice to hear something from Epson Moverio Team. Oh well!

~Bill

 

[Davo_101]

So I just checked again and I do have the cut outs, I must have hallucinated the solid backs somehow! So that's good and bad news. I modified my fan enclosure with some cardboard strips so the fan only blows on the bottom of the controller and ducted the flow with gaffer tape. I then decided to run some tests. Rather than have to sit with the glasses on I looked for easy ways to mirror the glasses to my PC. I haven't been able to cast to PC with Miracast, so looked for a USB alternative. I found a chrome extension called Vysor allows me to mirror the glasses and take snapshots of the screen and control using keyboard and mouse. This allowed me to watch about 3 hours of YouTubes and monitor the heat and charge levels. The charge levels come from the PC USB power and charge rate in Ampere showed between 600 and 1000 Ma. Max temp with fan was 38C and averaged 35C. Without fan temp rose to 42C after about 15 minutes. Looking forward to trying in flight now.

I am contemplating one of these:- https://www.amazon.co.uk/Aluminium-...8&qid=1527326183&sr=8-2&keywords=heatsink+4cm as it looks as if it will fit neatly into the bottom cut out on the mount. Can I power this from a USB power bank - if so is there a converter for the socket connection to USB?

Vysor requires a subscription - you have a very short trial - but it works great, so I coughed - Moverio screen full screen on my 4K monitor is cool. Only downside is that the USB port must be in debug mode. After initial connection via USB you can switch to wireless, but if you connect DJI controller it takes over the port and you disconnect the display. I think I will use this alot for maintaining my Movs - installing apps, browsing the net etc. so much easier on a big screen with KYBD and Mouse.

Thanks all! David

 

[bmelody]

Hi David,

Great idea on mirroring the video output. I will try that on my next set of tests. Someone in another thread was able to get the BT's to cast wireless to his phone I think I will try it so I can keep the USB port available.

For some reason Ampere gets confused (perhaps its me) but it will show a very high rate of charge when connected to a USB supply of any kind. It totally confused me at one time. So now I use a bench power supply and/or a amp meter is series with the supply so I know the exact current flowing. For example when using the current limiting resistor and reading 40mA on my external meter Ampere reports I am charging at >1000mA. I think the app is getting the sign screwed up. In any case do not believe Ampere reading as gospel. The math simply does not work. Also the BT's will limit the charge current to approximately 450mA max.

I looked at your little fan on a heatsink and it looks interesting. It is not available in the USA however I ordered a similar fan and it should be here today or tomorrow. Here is a link to the one I ordered ; https://www.amazon.com/gp/product/B077BPPFN8/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 The one you found has a much better price.

If you order the fan get some heat conducting sil-pad? You will need it. here is a link;
https://www.amazon.com/100x100x1-5-...rd_wg=CMzbn&psc=1&refRID=3V8ZGVV0KMYPGR4P0RSM

I also ordered a heatsink without a fan to see if a heatsink alone could help.

~ Bill

 

[Davo_101]

Thanks - electronics is not my strongest suit and I have limited capacity for DIY. I admit I am a of a bit kak-handed bodger, and prefer to buy than make - I know my limitations.
I really appreciate your expertise in this area. Thanks for the tip about the heat conducting pad - I would never have thought of that I was thinking that paste would be a horrible mess on the Moverios!

Will let you know outcome.

David.

 

[chuck1026]

Hi Chuck,

Thanks for the response. I think an aluminum back would solve most of the heat issues as well. I am going to check with my son-in-law to see if can help in any way. He is a mechanical design engineer at Intuitive Surgical. He designs robots that operate on people. He may have access a printer that can a least make a prototype.

I opened up the BT's. Got as far as getting the touch pad off but did not totally remove the case. Do you think we can gain access to the CPU and battery to make contact with an aluminum back using sill pads to get the maximum heat transfer?

I have some heatsinks and fans on order from Amazon to see if I can suck some heat out using a passive device.

Looks like DV has a 3D printer maybe he can make a new holder that incorporates a fan with a duct for the air to properly flow.

David, you need to open up the back of your holder. DO you know anyone with a mill? If you have access to a mill it would be very easy to open that back area up. Opening up the back is an absolute must on your do list.

With enough of us coming up with ideas we will get this to a level of confidence where we can trust in the BT's again.

Sure would be nice to hear something from Epson Moverio Team. Oh well!

~Bill

I haven't had a chance to open up the case again to take a closer look. I would love to have a replacement aluminum back that could serve a heat sink and maintain the shape or the polymer back. Then it would still work with a fan pack if needed.

As soon as I open it up I'll post pix.

 

[DVegaman]

Can feel the air flow now.

 

[bmelody]

Very nice DV. Have you had a chance to try it out yet? Better hang on tight to the controller so it doesn't become airborne.