Does the P2 need a dedicated charging port

[Asiyura]

Dedicated charging port with the ability of charging via usb is the best for me, I wouldn't want to loose either option.

If I want to make some kind of "docking station", having a dedicated charging port allows to use the OTG USB port as host.

That makes 2 USB ports available on pandora instead of only one, without any need for a hub (just an OTG cable).

 

[Binky]

I've added another question since I can imagine a lot of people who would find a dedicated charging port helpful.

I'd be happy loosing the dedicated charger, as long as the microUSB can take high currents, and the fullUSB can manage low/full-speed (and superspeed?)

 

[Neelix]

I've added another question since I can imagine a lot of people who would find a dedicated charging port helpful.

I'd be happy loosing the dedicated charger, as long as the microUSB can take high currents, and the fullUSB can manage low/full-speed (and superspeed?)

And what happens if you need to charge your unit while running with wifi on, and SD Mass Storage to a device that honours the USB spec?

I may have said this before but I still believe that relying on out of spec devices for more power than they were designed to supply seems like a very bad idea..

- Neelix

 

[Binky]

I though there was a fancy new USB power spec that allowed negotiable power delivery in either direction up to several amps?

 

[GoldenSun3DS]

@Binky: While the P2 has the potential to be able to receive high voltage, it has to be used with a device that can output high voltage to get the full effect.


Think about it like this: While your HDTV (the Pandora) can receive HD video, your VHS player (device that's incapable of outputting high voltage) can't output HD video, so your HDTV wouldn't get full HD video when receiving video from your VHS. In order to receive HD video for your HDTV, you'd need a blu-ray player (device that can output high voltage).

Of course, this problem could easily be solved by using a USB-to-wall-plugin adaptor.

 

[TrashyMG]

@Binky: While the P2 has the potential to be able to receive high voltage, it has to be used with a device that can output high voltage to get the full effect. Think about it like this: While your HDTV (the Pandora) can receive HD video, your VHS player (device that's incapable of outputting high voltage) can't output HD video, so your HDTV wouldn't get full HD video when receiving video from your VHS. In order to receive HD video for your HDTV, you'd need a blu-ray player (device that can output high voltage). Of course, this problem could easily be solved by using a USB-to-wall-plugin adaptor.

^ I think you need to brush up on electronics, the set voltage of a device has nothing to do with this.. The amount of current draw does.


Your analogy doesn't make any sense either..A VHS player most likely ran on a higher voltage due to motors and old TTL logic circuitry... and why would you be drawing power off a VHS player?

 

[Binky]

USB provides 5V DC.

The normal specs say that a device can draw 100mA, and a further 400mA (to a total of 500mA) on negotiation with the host. The output voltage may be dropped if the slave attempts to draw too much current. A dedicated charging port is indicated to the slave device by the two data pins being shorted together. The absolute maximum that can be carried simultaneously to hi-speed data transfer is 900mA due to interferance problems.

I believe (will research in a moment) that there are new specifications which allow the slave device to source (or sink) rather more current, when connected to a suitable host.

Edit: http://www.usb.org/developers/powerdelivery/

 

[Nintendo]

@Binky: While the P2 has the potential to be able to receive high voltage, it has to be used with a device that can output high voltage to get the full effect. Think about it like this: While your HDTV (the Pandora) can receive HD video, your VHS player (device that's incapable of outputting high voltage) can't output HD video, so your HDTV wouldn't get full HD video when receiving video from your VHS. In order to receive HD video for your HDTV, you'd need a blu-ray player (device that can output high voltage). Of course, this problem could easily be solved by using a USB-to-wall-plugin adaptor.

hahaha funny stuff, mate.

 

[thatgui]

And what happens if you need to charge your unit while running with wifi on, and SD Mass Storage to a device that honours the USB spec?

I may have said this before but I still believe that relying on out of spec devices for more power than they were designed to supply seems like a very bad idea..

- Neelix

But how likely is it ? Almost every device produced in the last +5 years already violates the standard, and there is no reason to believe that manufacturers will start sticking to the standard in the future.With USB3 slowly seeping into the market, this will become an even smaller problem.

I just don't see the benefit any more, as a "powerhost" that adheres to the standard is becoming a niche itself. So why waste money and precious space ?

 

[Binky]

Because standards are good.

The P2 should generally adhere to the most recent applicable standards wherever possible, IMO

 

[thatgui]

Because standards are good.

The P2 should generally adhere to the most recent applicable standards wherever possible, IMO

True, but looking at USB I have to disagree heavily: Implementation superseded the standard while the design group(IBM, Intel, MS,etc.) did not do anything to counteract that.

 

[Neelix]

It's a mistake to assume that no-one implemented the standards according to the specification.   I have encountered USB2 ports which do conform to the spec and don't supply more power than they are supposed to. (it took me a while to figure out why I couldn't charge my phone from them)  

Additionally,  even if the host hardware isn't limiting the current per the specification that doesn't mean it's not designed with compliant devices in mind.   It could be that by drawing too much current from a USB port you could potentially  damage the host device.

- Neelix

 

[Grench]

Dejavu.

http://boards.openpandora.org/index.php/topic/10184-more-pandora-2-crap-microsd-split/?p=191116

 

[thatgui]

It's a mistake to assume that no-one implemented the standards according to the specification.   I have encountered USB2 ports which do conform to the spec and don't supply more power than they are supposed to. (it took me a while to figure out why I couldn't charge my phone from them)

I did not assume that. What I'm basically saying is that (as with almost every other part of the Pandora), you have to weight the pros and cons. In my opinion, getting lost of the dedicated port will have some tiny effect on costs, but could free up some space on the board (which could be used otherwise, or skipped to reduce volume). Sure we will lose some flexibility with it, but (imho) it is worth it.
Does your phone only charge after a certain current threshold is reached ? If so, does the Pandora have this threshold too ?

The scenario you mentioned earlier is a scenario I'm living with my Pandora the past two years without a problem connected to different devices - mostly my notebook though.

Additionally,  even if the host hardware isn't limiting the current per the specification that doesn't mean it's not designed with compliant devices in mind.   It could be that by drawing too much current from a USB port you could potentially  damage the host device.

I do not see a real connection to our discussion here. This problem already exists with the current implementation or is there a circuitry in the P1 that pretends it from demanding too much power from the host ? And if so, why couldn't this be in a P2 ?

 

[SNESFAN]

Keep the redundant charger port. I've had too many devices break off that port and become useless as there is no longer a way to charge.

Even with fast charging 2A via mini/micro USB with a wall charger not all usb host devices pump out that much amps. My laptop can't charge my iPad but my desktop can.

My vote is very much in favor of the current setup.

 

[Exophase]

Keep the redundant charger port. I've had too many devices break off that port and become useless as there is no longer a way to charge. Even with fast charging 2A via mini/micro USB with a wall charger not all usb host devices pump out that much amps. My laptop can't charge my iPad but my desktop can. My vote is very much in favor of the current setup.

Did that happen to your JXD S7300? Mine's almost at that point :/

 

[SNESFAN]

Keep the redundant charger port. I've had too many devices break off that port and become useless as there is no longer a way to charge. Even with fast charging 2A via mini/micro USB with a wall charger not all usb host devices pump out that much amps. My laptop can't charge my iPad but my desktop can. My vote is very much in favor of the current setup.Did that happen to your JXD S7300? Mine's almost at that point :/

Nope, that one is still holding strong and it also has a DC power. (Don't need it, till ya need it)

The ones that died on me were 2 HTC evos (first gen) a evo 3d which I got repaired and an iPod touch, my wife's iPhone is almost on its way out the door as well.

 

[Exophase]

Nope, that one is still holding strong and it also has a DC power. (Don't need it, till ya need it)

I forgot that it had a dedicated power port, on account of my refusal to use the supplied charger after hearing stories of it exploding.

 

[SNESFAN]

Nope, that one is still holding strong and it also has a DC power. (Don't need it, till ya need it) I forgot that it had a dedicated power port, on account of my refusal to use the supplied charger after hearing stories of it exploding.

I can see that as a flaw for sure Lol. That style appears to be popular for the Chinese, I got like 6 devices that use that skinny little pin style.

 

[TrashyMG]

I forgot that it had a dedicated power port, on account of my refusal to use the supplied charger after hearing stories of it exploding.

The one that came with my CC unit is most certainly very sketchy.. It stopped working all the sudden, loosen a screw and the power light on it comes back on again.. I took it apart and saw a cap gets shorted if pressure of the plastic casing causes it to touch another component..
The GC ones or whatever ED ordered are fairly decent.