57 replies to this topic

[Polossatik]

Hum, I was under the impression MWeston changed the design so that the Pandora worked without battery...
Is this not the case? (I might be mistaken, I know normally this ARM chipset needs an battery connected to work)

[Exophase]

Does this mean, that the Pandora do not even turn on instantly, when the Handheld is pluged into mains? Or can I instantly use the Pandora during (first) charging?

I want to know this too. Am I interpreting correctly that this means the Pandora is not powered directly from the AC adapter but that the adapter only powers the charging circuit?

[God Ginrai]

Does this mean, that the Pandora do not even turn on instantly, when the Handheld is pluged into mains? Or can I instantly use the Pandora during (first) charging?

I want to know this too. Am I interpreting correctly that this means the Pandora is not powered directly from the AC adapter but that the adapter only powers the charging circuit?

<•03:53:19 PM•> <•EvilDragon•> GodGinrai: Yeah, it always goes through the AC Adaptor.
<•03:53:24 PM•> <•EvilDragon•> Damn
<•03:53:29 PM•> <•EvilDragon•> Through the Charging Circuit.

It still works without a battery in, though.

-God Ginrai

Edited by God Ginrai, 25 May 2010 - 07:56 PM.

[Polossatik]

Might be an idea to ask Mweston for some final words on this.
If the battery needs to hold charge to "bootstrap" the charging process then it might be a very good idea to ask people to NOT turn the pandora on until it's say's "full" (or whatever is safe).

[hch]

ah, i'm too lazy to dig this age-old thread out, but yeah, you couldn't charge and run at least early prototypes at the same time. but i thought mweston did some magic on the rev.4/5 board to fix this?

[God Ginrai]

ah, i'm too lazy to dig this age-old thread out, but yeah, you couldn't charge and run at least early prototypes at the same time. but i thought mweston did some magic on the rev.4/5 board to fix this?

He did.

-God Ginrai

[Pickle]

Does this mean, that the Pandora do not even turn on instantly, when the Handheld is pluged into mains? Or can I instantly use the Pandora during (first) charging?

I want to know this too. Am I interpreting correctly that this means the Pandora is not powered directly from the AC adapter but that the adapter only powers the charging circuit?

isnt it the same chip that handles it all?

it sounds like new users getting pandora should first plug it into the wall and let it charge, I think it will turn on instantly (at least it has for me from what i can remember)

Edited by Pickle, 25 May 2010 - 09:38 PM.

[Polossatik]

ah, i'm too lazy to dig this age-old thread out, but yeah, you couldn't charge and run at least early prototypes at the same time. but i thought mweston did some magic on the rev.4/5 board to fix this?

He did.

-God Ginrai

Really? So why don't they start with the mains adaptor plugged in?

[God Ginrai]

ah, i'm too lazy to dig this age-old thread out, but yeah, you couldn't charge and run at least early prototypes at the same time. but i thought mweston did some magic on the rev.4/5 board to fix this?

He did.

-God Ginrai

Really? So why don't they start with the mains adaptor plugged in?

They do.

-God Ginrai

[EvilDragon]

When a battery is inserted, the power goes into the battery, charges it and the battery powers the Pandora.
When no battery is inserted, the power goes through the charging circuit directly into the Pandora.

This means: If the battery is really empty, the Pandora won't power on when connected to AC until the battery reaches a certain voltage level.

[Pickle]

ah, i'm too lazy to dig this age-old thread out, but yeah, you couldn't charge and run at least early prototypes at the same time. but i thought mweston did some magic on the rev.4/5 board to fix this?

He did.

-God Ginrai

Really? So why don't they start with the mains adaptor plugged in?

Edit: read ED's statement

Edited by Pickle, 25 May 2010 - 08:15 PM.

[Poem58]

So what I get out of this is:

If the Pandora is plugged into the mains adapter, the charge circuit will focus on charging a battery if present. The Pandora will draw directly from battery as the charge circuit is busy charging battery and cannot supply enough to run charger and Pandora.
As long as the battery has enough charge to support the Pandora it should run while charging.
In the future, if the battery is no longer holding a charge, remove battery to power Pandora from mains adapter.

Edit: I see with ED's post above this is right, and simple enough.

Edited by Poem58, 25 May 2010 - 09:08 PM.

[Exophase]

When a battery is inserted, the power goes into the battery, charges it and the battery powers the Pandora.
When no battery is inserted, the power goes through the charging circuit directly into the Pandora.

This means: If the battery is really empty, the Pandora won't power on when connected to AC until the battery reaches a certain voltage level.

Okay, that explains it, thanks. I was concerned the Pandora would need a working battery to function.

[MWeston]

When no battery is found on AC adapter insertion, the unit goes into constant voltage mode which provides a constant 4.0V on the battery net. It doesn't like it if you put a battery in at this point because the TI chip doesn't appear to be designed to jump back to normal mode without a power cycle. It could do weird things like dump ridiculous amounts of current into the battery without software control. I liked the idea of letting customers power without a battery so we left this feature in but be aware of this restriction:

IF YOU POWERED THE SYSTEM WITHOUT A BATTERY, SHUT IT OFF BEFORE STICKING THE BATTERY BACK IN. (not an angry sentence, just making it clear.)

When the battery is inserted first, the system will power up using the normal mode. When the AC adapter is plugged in after this, it will power the system and charge the battery up to the limits set in software. Currently, Notaz and I have chosen 1A on the AC adapter and 600mA from the USB input. It can be changed by sending commands to the chip to alter these set numbers but that is a software lesson better learned from someone else. With the LCD off (lid closed perhaps) idling on the desktop, something like 750mA will go to the battery for a 6 hour charge time or so. With the system doing stuff and demanding more power, less current will go to the battery and it will charge slower. 1A was also chosen to consider thermal dissipation because the regulator of the TI chip is linear and wastes energy dropping the voltage from the 5V down to just above the cell voltage. You may notice the system feels warmer when the battery is more discharged than when it is full which is normal.

I haven't had much luck hot swapping batteries while the system is live but I think it worked for ED once. For me, as soon as I pull the battery, the system resets. The power management chip seems to rely on the status of the thermistor in the battery and it if disappears, it can trigger events. Maybe there are software work arounds but I don't know.

[Wolfsclaw]

IF YOU POWERED THE SYSTEM WITHOUT A BATTERY, SHUT IT OFF BEFORE STICKING THE BATTERY BACK IN. (not an angry sentence, just making it clear.)

I hope this is getting added to the Quick Start Manual, sounds very important indeed to me.