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Topic: Back-Up Battery with Arduino Micro (Read 791 times) previous topic - next topic

Belial88

Hi. Okay so I have a really complicated project, I'm just going to give you the basics.

I have an Arduino micro, and I'd like to run it off my computer USB for both power and data. Simple, right. Okay, now for reasons to avoid a 3 hour explanation of what I'm doing, I'm just going to say that the Arduino needs to also run when the PC is off, for just power.

Hence, I need a back-up battery. And I do have a back-up battery, a cell phone battery that can both charge and be charged at the same time, that I hook up to the computer's PSU (so it's charged up when the PC is on, and then when off it supplies power to the Arduino).

My original plan was to tie the 5v/Grnd of the battery to the arduino, and data to PC, that way it just runs always off the battery power, but apparently that doesn't work, the PC just won't recognize the arduino and acts funky.

SO - what I need to do, is hook up the Arduino Micro to the USB, just like normal, 5v/d+/d-/grnd, but also have a battery hooked up to the arduino. Perhaps the VIN pin? And so when the PC turns off, the arduino runs off this battery.

If it's relevant, the Arduino Micro will also power a small micro servo (under 1amp) off it's 5v pin, in both battery operations.

Thanks. Had to type all that out and that's a very basic groundwork of the project. Please do not derail my thread asking what I'm doing, I can link you to my projects and such if you'd like and you can take the discussion there, this is hopefully just a basic question on back up battery power.

CrossRoads

You might have to get power to VUSB to keep the USB interface alive so that when data comes in the USB interface is not dead and starting from scratch.
Not sure that's accessible on an pin, may have to jumper to the polyfuse near the USB connector. Probably on the "board" side and not the USB connector side so that when you plug in to the computer you have that slight resistance and the PC does not see a higher voltage than it has.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Coding Badly

I'm just going to say that the Arduino needs to also run when the PC is off, for just power.


Buy a powered hub.

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Hence, I need a back-up battery.


Buy a small UPS for your powered hub.

Belial88

I'm not following what you are saying, but when the PC is off, there is no need for the data lines anymore or the USB connection. My arduino micro is doing multiple tasks, the code is already written up and everything, I've just had some trouble with implementation because I figured the whole data/data to pc and 5v/grnd from battery wouldn't be a problem, but instead the computer is being a pain and not recognizing the arduino unless it's feeding the power too.

I briefly attached a fan to the 5v/grnd lines of the usb, and that actually got the PC to recognize the arduino connected only by data lines, but for some reason it stopped working and well that wasn't really a viable long term solution anyways.

I dont know what an 'an pin' is. Or VUSB.  Not really following what you are saying at all ;/

As for a powered hub, I'm not really familiar with what it is. I looked it up... so... I still dont get it. I would plug the micro into one of the usb slots, then the hub to the PC USB... and then the hub to the cell phone back up battery?

Coding Badly

As for a powered hub, I'm not really familiar with what it is. I looked it up... so... I still dont get it.


A USB hub with a separate power supply.  All of the ones I have used will automatically switch between the separate power supply and the up stream power available from the host computer.

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I would plug the micro into one of the usb slots,


Yes.

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then the hub to the PC USB...


Yes.

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and then the hub to the cell phone back up battery?


If it meets the power supply requirements of the hub you buy.  For example, the powered hub on my desk requires regulated 5V DC.  To power all seven ports the power supply must be able to deliver 3.5 amps.  Your battery / charger would have to provide regulated 5V DC and about 1 amp if you were to use the same hub.

Belial88

The cell phone battery pack I have is this one:
http://www.amazon.com/PowerGen-PGMPP6000-External-sensation-Thunderbolt/dp/B008TXCMFQ/ref=pd_sim_cps_4?ie=UTF8&refRID=04KXZ5ECX197ZZG7PJ36

It's 6000mah, 5v@1amp. So instead of plugging in a 5v wall wart, I imagine, into the powered hub, i would wire the back-up battery to it instead (splice so it's 5v/grnd go into approrpriate spots on the usb hub)?

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