(12-18-2017, 09:33 AM)dkryder Wrote:(12-18-2017, 08:30 AM)xalius Wrote: There are no -5V anywhere on the board... why does this keep coming up? DC input is a positive 5V potential difference vs GND....good question. several new members raising the issue of -5v. so maybe because some other boards they know about and think those boards have -5v they come to the rock64 forum knowing very little about the board and start making assumptions? i've noticed just about the same thing with the issue of supplying 5v to gpio, that has been raise in several threads by i guess folks from rpi and others reading that it is done. of course it is done by many but that does not mean it is good thing to do. rock64 has some voltage and surge protection on the proper 5V in connector line and does not have that on the 5v gpio lines. as well as any diodes on the proper 5v line will of course mess with 5v from gpio. i'm sorry for being crass by mentioning this but it is entirely possible for nutrition and energy to be supplied to the human body by putting a feeding tube in the anus. but usually folks just eat and take supplements via oral, the mouth. so, apply 5v energy via designed inputs and not designed outputs.
The -5V is neutral. Most adapters have a +5V, -5V (neutral), and ground. Personally, I do not like to refer to the neutral as -5V, though that is how it is refferred to in other posts on this forum. The barrel jack on the board has 3 pins connecting it to the board. Is the third pin for structural integrity then?
(12-18-2017, 10:57 AM)nmhart322 Wrote:(12-18-2017, 09:33 AM)dkryder Wrote:(12-18-2017, 08:30 AM)xalius Wrote: There are no -5V anywhere on the board... why does this keep coming up? DC input is a positive 5V potential difference vs GND....good question. several new members raising the issue of -5v. so maybe because some other boards they know about and think those boards have -5v they come to the rock64 forum knowing very little about the board and start making assumptions? i've noticed just about the same thing with the issue of supplying 5v to gpio, that has been raise in several threads by i guess folks from rpi and others reading that it is done. of course it is done by many but that does not mean it is good thing to do. rock64 has some voltage and surge protection on the proper 5V in connector line and does not have that on the 5v gpio lines. as well as any diodes on the proper 5v line will of course mess with 5v from gpio. i'm sorry for being crass by mentioning this but it is entirely possible for nutrition and energy to be supplied to the human body by putting a feeding tube in the anus. but usually folks just eat and take supplements via oral, the mouth. so, apply 5v energy via designed inputs and not designed outputs.
The -5V is neutral. Most adapters have a +5V, -5V (neutral), and ground. Personally, I do not like to refer to the neutral as -5V, though that is how it is refferred to in other posts on this forum. The barrel jack on the board has 3 pins connecting it to the board. Is the third pin for structural integrity then?
I actually just answered my own question. The 5V barrel wall adapter for the rock64 (or pretty much any barrel adapter) has only 2 wires, thus it is +5V and either neutral or ground, whatever you want to call it. Usually when you hook up electronics to +5V and ground (with larger electronics), it causes a short in the breaker. But I guess with this board, the returning voltage is so minimal that it doesn't matter
Here is a website that explains all this positive, negative, and ground scenario
https://electronics.stackexchange.com/qu...l-and-grou