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Misc. electronic conspicuity boxes: Garrecht / Air Avionics / TRX-1500A / Air Connect / PAW / PilotAware / LXnav / PowerMouse / FlarmMouse / Flarm / Uavionix / SkyEcho / SafeSky

Not sure it’s relevant to your question @Aveling, but while the SE2 has a USB-C port, it lacks any of the USB-C intelligence, and will not charge the battery from a “normal” USB-C charger, but will a “dumb” charger.

If you don’t mind soldering, you could open it up, remove the battery, and wire up the equivalent voltage power supply in place of the battery.

If you have not already, you might have a talk with Mike Tetlow who’s the UK contact for Uavionix to see if he can suggest a solution or an improvement in future versions. He’s a really helpful guy.

Fly more.
LSGY, Switzerland

Has anyone connected the SE via the two USB power wires and measured the current? It should be under 500mA, otherwise it is a dumb design.

If it draws say 400mA but that isn’t enough to sustain it, that’s dumb too; they should have implemented higher power USB.

If it draws over 500mA but there is no power negotiation, that’s ultra dumb because the source may trip out. It is entitled to trip out at 500mA.

Shoreham EGKA, United Kingdom

Aveling wrote:

Sorry if this has been covered before but have looked and not found it. Skyecho has an annoying feature that it can’t charge from USB when in use. This is apparently due to non standard USB wiring inside the unit, possibly because the operating current is too high for USB.

It seems Skyecho just implemented the standard USB charge protocol, but is not equipped with a charge-through add-on functionality. So far, so easy, but yes, annoying they did not implement that feature at first glance.


standard USB charge protocol

What is that?

Shoreham EGKA, United Kingdom

I did query this with a couple chaps at one of the shows and they gave a fairly unconvincing explanation regarding USB gobbledegook but were clearly aware of the problem. Maybe the real reason is regulatory – avoiding it being construed as ‘installed’ or something?

So tomorrow I have to make an unnecessary car journey to retrieve the thing from the plane and bring it home for charging. I’ll have a go at measuring the currents etc..

Why is this collision avoidance stuff all so amateurish?

EGBW / KPRC, United Kingdom

USB is a horrible protocol which works as well as it does only due to the application of a vast mountain of R&D money by the biggest corporates I’ve just finished a product which has a USB interface so I’ve seen a bit of it…

But the power side isn’t so bad. Start by connecting just pins 1 and 4 to +5.0V and measuring the current drawn. Then try 5.25V. The answer will be illuminating

Shoreham EGKA, United Kingdom

There is a lengthy explanation of this SE2/USB issue on the Flyer Forum, written by someone who clearly knows their stuff and has investigated it in detail.

In short, even though the connector on the SE2 takes the physical form of USB-C, it is not a USB-C port and cannot be relied upon to behave like one.

The practical effect of this is that when powered off the unit will accept charge, but if powered on it will do unexpected things depending on the exact properties of the charger connected to it. He was able to demonstrate that in some instances this included getting hot enough to melt some of its components.

Given the 12hr battery life I have never felt the need to charge it while in use. I don’t like cables in the cockpit anyway. Flying schools that use them just charge them overnight and then leave them in the aeroplane all day.


I don’t readily buy that, especially the components melting. USB-C delivers +5V just like the old USB, on the VBUS pins

That’s why you can get e.g. USB2 to USB-C adaptors or cables.

What USB-C can do is negotiate a higher voltage on VBUS, up to +20V, but if the device is dumb it will just be getting +5V.

I’ve done a product at work which is micro-usb but I am changing the connector to usb-c because the latter is more robust in terms of getting ripped off the PCB. Nothing else changes…

Shoreham EGKA, United Kingdom

I looked at the above mentioned description (a vast long inconclusive thread from 3 years ago) of the SE USB power arrangement and it appears that it attempts a negotiation for 1 amp and that’s it. So it cannot be connected to anything but an “intelligent” USB charger. It cannot be connected to some USB port on another device.

Whether 5 watts (5V and 1A) is enough to sustain the SE during operation, doesn’t appear to be stated. I also don’t think the guy quite understood USB charging.

There was a response by SE who just say you should charge via USB-C from a charger which can do at least 18W and should not charge in the aircraft. But 18W doesn’t relate to 1A so maybe the SE draws a lot more at times.

Sounds like a bodge, which they get away with because most GA flights are short so people mostly charge at home.

Shoreham EGKA, United Kingdom

12 hour battery life and flying schools use them dawn to dusk quite happily, and in any case it avoids cables in the cockpit.

I think 12 hours would test even your capacity for long flights Peter? :-)

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