Sense When No Phone is Plugged Into a USB Charger In Vehicle

versus pull some veroboard from a box, solder it in, done.

Using a microprocessor to convert a dc signal into a dc signal is not something I'd be in any hurry to go for.

If you're asking that in an electronics newsgroup, something is rather wrong.

NT

I don't get it. You are just trying to sense if any thing is plug in. Just sense any signal on the data pins. Why do an analog solution for a digital problem.

How come it's called the "Nanny State" and not the "Daddy State", anyway?

More than that. You want a momentary push-button switch to manually silence it until the next time it's powered up. So add some sort of a flip flop, and be sure that it resets on power-up (with an Arduino, just hook a switch to an input (pull up already inside).

The bottom line is that doing it with discrete analog chips, and adding all the extra stuff, is a lot more complex, and more work, than using a micro-controller that already has digital and analog I/O.

I don't know what sort of setup you've got, when I plug my phone in there are no data connections going on.

If you are connecting to data pins and you can rely on them being active always, then you coudl skip the opamp as well as the arduino. 1 transistor, 1 LED, 2 resistors would do it.

NT

no, that's how you want to do it. You seem to be forgetting there are 4 sections in a 324. section 1: current sense

NT

All phones can be connected to PC/labtop as device. There are data pins, unless you are using special charging cable without them.

You can just sense some pull up and/or signal transitions, or do a full brown USB emulation.

I like the NFC solution, but more benign is a socket that the phone sits in (you'll have to build that) and detect the presence of a phone-shaped item, NOT any device-specific electric functions.

Use a relay or equivalent latch (that SETs every time accessory power goes OFF) to operate a buzzer. Then the phone just has to depress a button (the 'RESET' button) when inserted. Power-up with no phone, it buzzes. Insert the phone (or press the button) and the buzz stops. One buzzer, one relay, one momentary switch, and maybe a capacitor for the power-on reset.

Your new problem: the phone got left in the car...

aped

s OFF)

RESET' button)

press the

, and maybe

many years ago when it first became mandatory have the lights on all time, many had an alarm installed to remember to turn the light on and off

Ignition on and lights off sounded the buzzer, so you remembered to turn on the lights. Door open/ignition off and lights on sounded the buzzer so you didn't forget to turn them off

True.

There is no signal on the USB data pins that is any different when the phone is plugged into only power and ground versus not plugged in at all.

The only way to sense the presence of the phone is by sensing the current that flows into the phone when charging, versus no current flow when not charging. There could be a Bluetooth solution but it would be much less reliable and would not work if the Bluetooth on the phone was turned off.

Good point. I think I'll add a supercap so it runs for a little while when the vehicle is turned off and the Sonalert starts sounding when the

She left the phone in the car once in San Francisco. The person who broke the window to get it must have been terribly disappointed with a $100 Moto G with no resale value, and I got to pay $200 for a window replacement.

That's correct, unless it's plugged into a USB port in the vehicle that is more than just a charging port, and that connects to the entertainment system.

Won't work.

Isn't the point that you are enabling her assumption that other people will pull her out of a jam of her own doing? Seems to be a sort of victim thing too - poor thing forgot phone so husband or son must mess up their day to help her.

Really now, involving a bunch of people to solve a problem that she would fix herself if she had to drive back home a couple of times?

(why did she not pay to replace the window? She HAS a job and it was her phone that led to the window breakage...)

Now, if she is ill and coming down with Alzheimers or similar, then our hearts go out to you and your family and people will gladly help solve the problem.

However if she is healthy then she should deal with it.

John

PS, I still like having a sign beside the ignition lock, simple low-tech solution, eh?

I assume you're not married.

I still don't get it.

You are talking about a custom module between the phone and car. It's up to you to decide whether there are data pins on the phone side. Doesn't matter what the car has.

I am married. Together over eleven years.

She ran out of gas a few years ago and I happily brought her a can of gas from home. Then she got BCAA on her dime (like AAA) and she also carries an empty 5 liter gas can in her car in case she has to get gas again. I have also helped a friend who ran out of gas five or so years ago. And I ran out of gas once a couple of years ago and my wife came to my aid with the five liter jug.

As it is a very rare occurrence chances are I would help my wife or friend if they ran out of gas again, but not if it happened monthly or other shortish period of time.

None of us has run out of gas since.

I see no problem in helping family or friend who gets into trouble once over almost anything. Twice...maybe. Three or more times they are on their own as they aren't learning anything useful from my helping them to fix the same thing over and over.

John :-#)#

So you contradict your earlier statement. Figures. Lefties lie.