Provide power in via Pi-2 header

[BenCranston]

Well, that fully explains the issues I've been having.  I'm going to re-route the power over to the EULER bus and test again.  I'm worried however that I might have damaged something on the Pine64 by back-powering via the Pi-2 interface...

So, @pfeerick can you comment on @ciclopez assessment of the schematic?  Thanks.

So, have you been powering the Pine through the Pi-2 Bus and the microUSB port at the same time? I won't recommend doing that, but maybe the Pine has some protection for that use-case and your Pine could be fine, otherwise the MT3608 or your power sources might have been damaged, or maybe they just overheat.

I just did some measurements on the Pine and providing an input voltage of 4.97V through DCIN, the output voltage in the pins 2 & 4 of the Pi-2 Bus is 5.24V (this comes from MT3608) So I think it won't be possible to bypass the MT3608 by shorting Pins 4 & 8 in the Euler Bus, as the currents flowing from MT3608 to the power source could be of several Amps... unless I'm missing something.

Does anybody have an idea to bypass the power regulator?

Not at the same time, no.  I've been pushing 5v in via the Pi-2 bus, but it does not behave correctly.  The power source has supervision and can turn off and on the power.  there is something on the Pine64 that is causing the switch function to not work correctly, like a momentary dead short...  yikes.  If I over ride the switching and force the power on, the Pine64 will accept it and boot.  however I'm concerned that I'm damaging something.  Given the beginning of this thread where the belief was that Euler 5v In was directly connected to Pi-2 bus 5v, I'm starting to think that's not the case.

Later today I plan to re-route the input power over to the Euler bus and see what happens.

Well, I can fully confirm that you CAN NOT use the Pi-2 interface to power the Pine64.  You MUST use the Euler Bus (or USB or Battery) to provide external 5v DC in to the board.

Sure hope I didn't damage any components on the Pine64..

[ciclopez]

I've found why some people say it's possible to feed power via Pi-2 and some say it's not. There is a jumper (J9) to bypass the MT3608 power regulator, but only in the Pine A64+ 2GB version, at least in the Rev C. So yes, it's possible in A64+ 2GB Rev C (maybe also in previous revs), but it's not possible in any other version, at least for the moment.

[BenCranston]

I've found why some people say it's possible to feed power via Pi-2 and some say it's not. There is a jumper (J9) to bypass the MT3608 power regulator, but only in the Pine A64+ 2GB version, at least in the Rev C. So yes, it's possible in A64+ 2GB Rev C (maybe also in previous revs), but it's not possible in any other version, at least for the moment.

So are you suggesting that back power via the Pi-2 interface is possible if you remove both jumpers?  I have the board you are pointing out.  My jumpers are, according to the manual, jumped to DC 5V setting.  With the board jumpered as shown the MT3608 over heats and the board shuts down if you provide power input via the Pi-2.  Power input via the Euler DC IN pins works just fine.

[ciclopez]

I've found why some people say it's possible to feed power via Pi-2 and some say it's not. There is a jumper (J9) to bypass the MT3608 power regulator, but only in the Pine A64+ 2GB version, at least in the Rev C. So yes, it's possible in A64+ 2GB Rev C (maybe also in previous revs), but it's not possible in any other version, at least for the moment.

So are you suggesting that back power via the Pi-2 interface is possible if you remove both jumpers?  I have the board you are pointing out.  My jumpers are, according to the manual, jumped to DC 5V setting.  With the board jumpered as shown the MT3608 over heats and the board shuts down if you provide power input via the Pi-2.  Power input via the Euler DC IN pins works just fine.

As far as the schematic is correct, if you remove the jumper it won't work. If your jumper is in DC 5V position (pins 1&2 connected, pins 3&4 disconnected) back powering should work, as VCC-5V becomes the same line as DCIN, and should be the same as providing power through the microUSB port or DCIN pins in the Euler Bus.
I have the A64 512Mb version so I can't test this right now. I will ask to a friend that has de 2Gb version to test it and let you know.

[BenCranston]

I've got the jumper on my board set to DC 5v (pins 1&2) and if I try to back power it via the Pi-2 headers the Pine's power regulator gets *really hot* and after a few minutes the power to the CPU get's flakey and the CPU halts. Now, move the same power source over to the Euler bus and all works perfectly. I'm not using a battery on this system at all, so that's not part of the equation.

Interesting note, my power source utilizes a supervisory circuit to switch on the power going to the Pine and on the Pi-2 bus it senses something of a short and wont turn on. I can force it on, which is what I did to find that the Pine does not agree with the Pi-2 bus as power input.

[g_t_j]

Can anyone please verify which is the DC 5V jumper position and which the Battery one?
For example, in the photo bellow which position is it?
Thanks!
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[MarkHaysHarris777]

I cannot even believe this thread...

... there are only two pins that provide DCIN ( besides the micro usb connector )

euler bus  pin(6  +5v)

euler bus  pin(4  - gnd)

Period.


There are stickies in the DC Power In section ;   I'm going to wait a bit, then delete this thread for reasons of insanity.

[g_t_j]

I was talking about the jumper position (up/down) which supposedly allows the Pine to be powered by either DC or a lipo battery.

And all I asked for is someone to verify whether the position of the jumper in the above photo I uploaded is set to DC or to battery.

EDIT: I'm already powering the board through the Euler bus via a custom cable I made.

[MarkHaysHarris777]

I was talking about the jumper position (up/down) which supposedly allows the Pine to be powered by either DC or a lipo battery.

And all I asked for is someone to verify whether the position of the jumper in the above photo I uploaded is set to DC or to battery.

EDIT: I'm already powering the board through the Euler bus via a custom cable I made.

That is the vbatt position;  you will only get 5v for usb (other) if the battery is plugged in.  The jumper determines where the 5v is coming from for the bus(s) and for usb.  If the jumper is in the DCIN position (its marked right on the board) then the 5v for usb comes from the DCIN connection.  If the jumper is in vbatt position (as marked in your photo) the 5v comes from a step-up  &regulator derived from the lipo battery .

[g_t_j]

Excellent.

This is what I was looking for.
Many thanks!