Provide power in via Pi-2 header

[pfeerick]

Thanks for that Marcus.

And to address the questions that ciclopez and BenCranston raised earlier which I missed (my apologies!), ciclopez was correct, I had neglected to mention in my earlier statement that this was on a Pine64+ 2GB board (RevB in my case), which has the jumper for DC/BAT power.

However, as I indicated in my earlier post from June '16, and can be seen from the schematic, when the jumper is in the DC position, the 5v bus(es) are coupled directly to the DC_IN pin, and the pine64 can be powered from the 5v pins RPi header. So if you have a hat which powers your Raspberry Pi, as long as you have a pine64 board with a power select header, it will power your pine64. Nothing should overheat. The pine64 runs perfectly stable, drawing approximately 215ma @ 5v when idling with a HDMI connection active.

So that should hopefully end that confusion. The Pine64 512MB board does not have the jumpers, and thus can only be externally powered via the DC_IN on the euler bus. The Pine64+ 2GB board has the jumpers, and can be powered via the rPi header once the jumper is in the DC(_IN) position. As always, it is not recommended that you power via the headers (regardless of which header you connect to). MicroUSB is the safest option unless you know what you're doing!

@marcus: Do you know if the Pine64+ 1GB board has the DC/BAT jumpers on it? The schematic does NOT show it, and pictures of the RevB pine64+ 1GB do not show the jumper present. Unless there was a RevC which added it, the pine64 store page needs to be updated as it shows a board with the jumpers.

[MarkHaysHarris777]

@marcus: Do you know if the Pine64+ 1GB board has the DC/BAT jumpers on it? The schematic does NOT show it, and pictures of the RevB pine64+ 1GB do not show the jumper present. Unless there was a RevC which added it, the pine64 store page needs to be updated as it shows a board with the jumpers.

Pete;  there is some confusion about the 1Gb board too... apparently there is (although I can not prove this) a 1Gb board with the jumper.  I have assumed that the photo of the 1Gb board was correct (as well the 1Gb schematic) , and that the jumper came in with the 2Gb board.

IMHO the jumper is a really dumb engineering mistake;  and even the schematic for the 2Gb board has a note (which is an error) "When using DC 5v and battery supply together diconnect J9 1,2,3,4" .  The engineering problem with the jumper is that its a manual afterthoght. Of course the problem with removing the jumper is that some of the 5v pins lose power.  I leave the J9 jumper on vbatt, leave the battery plugged in, and leave the pine DCIN plugged in...  if and when the power goes out (happens in my neck of the woods) the battery (lipo) keeps things running for up to 10 hours.  The J9 jumper in vbatt position ensures that the 5v on the pins and the usb will continue. I have all of my boards (including the sopine board) jumpered this way.

I think the J9 jumper should be rethought in future boards, and should be automatic. ( there should not be a jumper!)

[pfeerick]

[...] apparently there is (although I can not prove this) a 1Gb board with the jumper.  I have assumed that the photo of the 1Gb board was correct (as well the 1Gb schematic) , and that the jumper came in with the 2Gb board.

IMHO the jumper is a really dumb engineering mistake;  and even the schematic for the 2Gb board has a note (which is an error) "When using DC 5v and battery supply together disconnect J9 1,2,3,4" [...]  I leave the J9 jumper on vbatt, leave the battery plugged in, and leave the pine DCIN plugged in...  if and when the power goes out (happens in my neck of the woods) the battery (lipo) keeps things running for up to 10 hours.  The J9 jumper in vbatt position ensures that the 5v on the pins and the usb will continue.

That was my belief also... that there was a 1GB Pine64+ with a jumper, but I can't see anything to support that. If that is not the case, the shop page is NOT correct as it shows a 1GB pine64 with a jumper, and the schematic is correct.

I'm in two minds as to whether it is a mistake or not. It certainly seems to have been an afterthought. I also usually leave it in the BAT position regardless of external power or not, for the same reason as you. Hence my interest in dual power supplies/battery power option for future designs... as it means the device has a built-in UPS as a bonus. However, I have had problems with automatic power switching designs in the past... with the most disastrous been the power circuitry self-destructing because it automatically did the wrong thing... so it needs to be robust and "fool-proof" (was a very strange interaction between the PMIC in charge mode, 5v boost circuitry, and a battery with self-protection circuit). However, I do find it handy to have the jumper when back-feeding via the rPi header, or when needing to power a USBHDD that needs more power to spin up than the PMIC will give it.