PINE64

Full Version: Secondary power input for Rock64 through pi2 Bus
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http://synfare.com/599N105E/hwdocs/rock64/index.html

Here is a link to the layout of the gpio pins on the rock64. If you look at the pi2 bus, pins 2 and 4 are labeled 5V input. Is this a viable option to power the board? I do not want to use the barrel jack because I am putting this board in a larger system that I already have a large 5V power supply for. If it is, do I connect the +5V to the 5V pin and the -5V to any ground pin?
You can theoretically do that, it may circumvent some of the input protection though, or rather make it less effective, since you are coming from the wrong side of the input filter... There is no -5V anyhwere on the board, the Rock64 only uses 5V as input, so only connect the 5V and GND pins.
i can confirm that this works Wink but idd +5V and GND (not -5V)
those pins are not 5VDC IN they are 5V source to power components from the rock64. to use them to supply power to the board is risky. get a copy of the schematic and look at the actual input power supply line and compare it to the 5v header circuit. if you want a solid 5v DC IN the remove the barrel jack connector from the board and hard wire the line from your power supply.
The difference between 5V on Pine64 an Rock64 is, that on the Pine64 the PMIC has an extra 5V output path, so you can't feed that backwards, on the Rock64 the PMIC does not control the 5V net. The Rock64 5V net is basically the same from input to output and also used for USB VBUS...
(12-17-2017, 06:44 AM)dkryder Wrote: [ -> ]those pins are not 5VDC IN they are 5V source to power components from the rock64.  to use them to supply power to the board is risky. get a copy of the schematic and look at the actual input power supply line and compare it to the 5v header circuit. if you want a solid 5v DC IN the remove the barrel jack connector from the board and  hard wire  the line from your power supply.

Thank you. I will try this.
but do not use the -5V as GND, use the GND from your power supply. otherwise you will get a difference of 10V which will most likely kill the Rock64. After reading this i finally understand your problem from the other thread. maybe you should look deeper into electronics before you solder anything. Damage done by wrong voltage is irreversible most of the times.