Accessories Diagram for reading light?

[Lacrymology]

I'm double posting this here and in the Developer's Corner because I don't know in which this would belong, sorry. Admins, feel free to close whichever thread seems less appropiate.

Does anyone know what's the specifications for making a reading light like the ones that the "official" covers come with (http://www.amazon.com/Kindle-Lighted...p/B003DZ165W)? They seem to power through the same socket that the serial link is connected through, and there's some kind of.. hook? on the upper socket, whch I have no clue what it is for (ground, maybe?)

How does one get voltage out of that? what's the tension? I'm guessing it's just enough current to light a single small white LED.

[itakatz]

It depends what type of Kindle you have. The link you gave (which btw is broken because it included the ")?" at the end) is for the keyboard version. Have a look at this thread: https://www.mobileread.com/forums/sho...09#post1367909

[geekmaster]

On the K3, the smallest connector is the ground pin in the bottom left slot, which is also used for serial communications. It is a very small pin so limits electrical current, but you *could* also use the USB jack for a better ground. The power pin in the top slot is quite large.

On the K4 and K5, the square pads on the back are ferrous so that you can connect to them with magnetic power connectors. To connect to these power pads, you could use tiny magnets taken from "magnetic stick and ball toys" (e.g. Magnetix brand), with wires attached, but then you would violate a patent for the obvious use of using magnets to attach a power connector (owned by Apple). On the K4 and K5, the ground pad is just above the USB jack, and power to the other jack is controlled by software (you can turn in on and off in diags). The K4 and K5 power pads should be able to handle more current than the K3 ground pin.

[ron0909]

Here's the one that I put together for the K3 using a used non illuminated original cover
and a 3 dollar USB flex LED lamp. Easy as pie if you have a little bit of soldering skill
and a bit of creativity. Please ask away if you have any questions
Ron

https://www.mobileread.com/forums/sho...d.php?t=174544

[Lacrymology]

@geekmaster: you pointed out on the other thread copy that the serial connection pins on the bottom need to be closed for the juice to start coming out of the top connector, right? so the top power slot is a single cable, and the two bottom ones need to be closed with whatever? (like, if I just hack in a paper clip that closes the circuit, then power starts coming out of the top connector?)

And then I need ground. So, second question.

You also said I could use the bottom connectors as ground. I've actually pried open a kindle and saw the ground connector which is right next to this slot, but wouldn't that break the live end of this two-pin short circuit? This is me not knowing enough of electronics asking. Or will the current just go harmlessly through the ground side of the switch?

Sorry about the noobness, I'm at that point in knowledge where I know enough to be a hazard, but not enough to be of use

[geekmaster]

Originally Posted by Lacrymology

@geekmaster: you pointed out on the other thread copy that the serial connection pins on the bottom need to be closed for the juice to start coming out of the top connector, right? so the top power slot is a single cable, and the two bottom ones need to be closed with whatever? (like, if I just hack in a paper clip that closes the circuit, then power starts coming out of the top connector?)

And then I need ground. So, second question.

You also said I could use the bottom connectors as ground. I've actually pried open a kindle and saw the ground connector which is right next to this slot, but wouldn't that break the live end of this two-pin short circuit? This is me not knowing enough of electronics asking. Or will the current just go harmlessly through the ground side of the switch?

Sorry about the noobness, I'm at that point in knowledge where I know enough to be a hazard, but not enough to be of use

Please ask technical questions in the Dev Corner forum. I do not want to get stomped on again for "talking tech" in this "general users" forum when I provide technical answers to technical questions.

Now that you asked this here, I will risk it again and give a useful technical answer: When you short the bottom pins, the combination is still grounded. One of them is an INPUT pin that normally floats high. Grounding it activates power to the top connector. That ground is shared by the serial Rx and Tx pins above it, and also used as the LED light power return path to ground. Try to not short your ground to the top Tx pin. Instead of a paperclip, there are posts here that show how to make a clip that fits into that slot, as part of a custom lighted cover. Check out the link provided by ron0909 above.

[Lacrymology]

yes, yes, I've seen those posts. Just asking if that was the thing, in principle

[geekmaster]

Originally Posted by Lacrymology

yes, yes, I've seen those posts. Just asking if that was the thing, in principle

Yes. You can also use the USB connector shell as a ground.