power supply

Started by chemaper, August 06, 2013, 11:53:55 AM

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chemaper

Is it possible to power the device via USB OTG port?

Is it possible to power the device via LiPo connector or it is only for charging? If both power supply and LiPo are connected and power supply fails, can the device continue working with the LiPo?

Regards:

Chema

XFer

Quote from: chemaper on August 06, 2013, 11:53:55 AM
Is it possible to power the device via USB OTG port?

No (I tried it).

QuoteIs it possible to power the device via LiPo connector or it is only for charging?

No, it remains dead (tried with the 3.7v 1400mAh from my Olimexino 328).
Honestly I don't know the purpose of the LiPo connector on the OLinuXino A20.

Fernando

chemaper

Thank you for your feedback, Fernando.

It's a pity that power on USB doesn't work  :'(

I've searched more about the LiPo in the forums and the blog. This post says that A13 works with a LiPo battery:
http://olimex.wordpress.com/2012/08/27/a13-olinuxino-rev-b-works-fine-from-lipo-battery/. I think both devices include an AXP209 IC. Another entry about LiPo batteries also includes A20 between the compatible devices: http://olimex.wordpress.com/2013/07/19/new-products-in-stock-lithium-polymer-batteries-3000mah-4400mah-6600mah/.

Perhaps 1600mAh are enough for an A13 chip but not for an A20, but it sounds strange to me (the A13 was tested with LCD and Wifi)

These photographs and video are curious: http://olimex.wordpress.com/2013/07/12/meet-oligobot-robot-chassis-with-a20-olinuxino-wifi-and-web-camera/  That A20 obviously is not powered with the power adapter; it seems to use 4 batteries!

Regards:

Chema.

Lurch

They mentioned several times that the linux kernel was not finished (well, the Android isn't either).
Dimitar may have used a kernel for his robot that included full / more support for the AXP chip.  From the pictures, you can't easily tell where the power is coming from - you would have to follow the wires and see which IO pins are being used.  There also appears to be a LiPo attached, but it can't be seen.  Maybe just to keep the RTCC clock running?
We probably have to wait for Olimex to get back from their vacation to solve this.

shamada

I haven't tested power via USB OTG yet, but I have tried the LiPo battery. And it works fine for me.
I have the big 6600mAh. Connected it and charged it via the normal power connector on the board. I was a bit confused about the LEDs though: The red LED shows "wall power is connected" and the yellow LED shows "battery is charged via wall power". So if you disconnect the wall power, no LED is on. So, when on battery you cannot see whether the board is running or not. But if you push the power button, both android and linux power up nicely. Android seems to show the correct power/charge level of the battery. On linux i haven't tested this yet. And just tried it: android still works after several days of sleep mode on battery.
BTW: I have the 7inch LCD connected and it's powered from the battery too.

Lurch

@shamada
what board revision are you using? Maybe there's a difference between A and D versions?

XFer

I have a Rev.C board, and did not boot when I tried my LiPo battery (1400mAh).
Maybe it was not 100% charged, but Olinuxino 328 worked happily on it afterwards, so there was some good charge in it.
I'll try again, with the battery at 100%.

Fernando

shamada

I've got a Rev. D board.

PaceyIV

I've bought two A20 Rev D board with a friend, and he say that the LiPo battery 14000mAh works fine!
He can power the board for a few hour with also sata powered by the power line near the sata connector.

Lurch

is he using an LCD or HDMI?

PaceyIV

Nothing.
He use only ssh remote console.

Lurch

Yeah, that would save a lot of power.
Mine use 7" or 10" LCD now.
Thanks.