Electrical Engineering

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Nick Alexeev

03:10

@Skyler If there'd a microcontroller inside of the RF module on that board, then it might have some nonvolatile memory.

7 hours later…

Asmyldof

10:38

@NickAlexeev Unless it's a TI Tiva series.... Well, it does HAVE EEPROM, but if you use it, you risk bricking the device

barlop

11:32

I've heard that it's bad for a power supply, to plug a device that requires more amps than it can send out. But if that's so then it's dangerous to plug a mobile phone into an old 500mA USB port 'cos a phone can draw 1A or 2A.

Bartek Banachewicz

@barlop not really, because the phone won't try to draw 2A before it confirms with the port that it's ok with it

the base USB spec allows 100mA of current drawn just after the device is plugged in. Afterwards, though, the phone can actually communicate with the charger and ask it about the maximum capabilities.

A: How to get more than 100mA from a USB port

I think I can attempt to clear this up. USB-100mA USB by default will deliver 100mA of current (it is 500mW power because we know it is 5v, right?) to a device. This is the most you can pull from a USB hub that does not have its own power supply, as they never offer more than 4 ports and keep a...

this answer has it all in more detail

barlop

that answer is very out of date

I was just asking an electronics question

I have a USB powered portable monitor that demands 2A. Is it possible that it might not communicate properly and then pull 2A from a USB port that wasn't designed to supply it?

Bartek Banachewicz

@barlop Which part of it is out of date?

barlop

@BartekBanachewicz well now there is USB3 which can send out more than 1.8A.

Bartek Banachewicz

@barlop No, if it's properly designed as an USB device. Yes, if it doesn't follow the spec or is e.g. damaged or modified.

@barlop Sure, but USB 2.0 devices and ports still exist. And USB 3.0 keeps backwards compatibility.

barlop

11:46

Yes but that answer didn't state that it was talking specifically about eg USB2

That answer says for example "USB by default will deliver 100mA of current (it is 500mW power because we know it is 5v, right?) to a device. This is the most you can pull from a USB hub that does not have its own power supply, "

No comment about it being specific to USB2.

Bartek Banachewicz

@barlop You can edit the answer and add that USB3 raises that to 150mA.

barlop

I don't know enough about USB to want to do that.

Bartek Banachewicz

Then leave a comment asking for an update. I am sure that some community member would bite.

barlop

there are already better ones like superuser.com/questions/690074/…

Bartek Banachewicz

@barlop I don't think that answer is better. It's different.

barlop

11:50

You could comment. You probably know more than me about it

When I comment I like to know a reasonable amount about it.

like if I critique something I like to be fairly thorough.

Bartek Banachewicz

@barlop I doubt it, I'm an electronics newb

Asmyldof

That answer is just as out of date. It does specify USB3 and USB2 as if the answers are as fixed as they are presented, but the USB3.1 portspec has extended the number of current profiles for standard port use and the C spec added different voltages as option to the data port as well

Bartek Banachewicz

@barlop well you don't need to know much to say "This has been written in 2010, perhaps it could be updated with the modern developments". It's not really critique.

barlop

Look that's just not the way I speak. Please if you want to comment just comment, don't ask me to make a comment that you think should be made.

5 hours later…

The Photon

17:01

@barlop FYI, the guy who wrote the answer is technically in the room right now (though he rarely speaks up). Why are you so worried about asking for an update on the main site but not concerned about doing so here?

PlasmaHH

17:58

A little windy today...

barlop

18:09

@ThePhoton who said I was so happy about asking somebody here to update their answer? Also, it might be a lot of work for them to do. Maybe they have other commitments.

Skyler

Hey guys, is it possible to compile the upload code for an arduino board into an executable. I've been working on ~40 arduino device that's been distributed to people across the nation and I'm trying to think of a simple way for the people who aren't tech savvy to get updates

4 hours later…