On Thu, Mar 27, 2008 at 8:18 PM, joerg <[EMAIL PROTECTED]> wrote: > Alas there is *absolutely* *NO* way for NEO though to tell when your > braindead > 850mA charger will start to slowly melt down overnight when you set 1A charge > mode via applet. It's very unlikely there will ever be any trouble other than > very rare occasional broken chargers, but we just can't guarantee it's safe, > for nobody knows all the chargers in this world.
As a hacker poking around with prototype hardware, that's a fine answer. For a mass market device, that's suicide. I understand that the Neo can't make the determination, but in the long run I think that Openmoko MUST. It is physically possible to charge the Neo at it's full speed (because it happens with the USB charger) so therefore it must be physically POSSIBLE to have an AC or DC based charger that does the same thing without requiring a computer tether. If any charger on the market can do this I think it would be simple enough for Openmoko to "certify" that the MODEL (not each unit, of course) is compatible and, unless it malfunctions, won't burst into flame. If there exists no such device on the market then perhaps that needs to be corrected either directly or indirectly. Put very simple "Car charging is a very big deal". Assuming the first (certification) or second (fabrication) options can't be met - drop the "fast charge" as a feature since anyone unable to fast charge in their car will consider their device "broken" at best or sold on a feature that doesn't exist. > However it's not our fault when sth really bad is happening, for every > charger/host is supposed to be short-circuit safe (mustn't burn, otherwise > probably mustn't be sold), I don't think anybody expects a certification of safety from Openmoko (there are voluntary organizations like Underwriter's Laboratories here in the US that will certify safety) for a product to go to market and even if they DID nobody can rightly expect you'll certify that no device will ever malfunction. > and it's the USER who has to think *before* > enabling 1A mode. Hey guys, when connecting your 110V device to a 230V outlet > in Europe, whom do you blame for the smoke?! The "common user" mentality is one that has, IMO, bitten Free Software repeatedly. As a serious (and non-belittling) thought exercise, how many people here know what amperage their car charger pushes out? How many people here have wives or mothers or nephews that know that answer? The average person buys a car charger because the box says "Compatible with <model>". Some might not even go that far since a commonly held assumption is that "if it fits in the hole, it will work". Yeah, kinda stupid, but it's also pretty reasonable to expect that this WILL happen. It's also reasonable to suspect that at least SOME people will take that and have it reflect poorly on Openmoko even if the charger was bought third party. It's sometimes easy to dismiss user stupidity when you're writing code that you use and the only signs you see are a ticking download counter or more hits in a server log, but this is something that I think could directly relate to the ability to sell SECOND units to people. > bottom line: USB is specified for 500mA at MAX, and even this needs > intelligent host (alias charger). Everything beyond has to have some > intelligence with it, either the one of the user not messing with chargemode, > or the one of OM-designers creating and checking for a proprietary way to > signal >500mA charger capabilities (=48k). > (PS: For the record: If i got this right, the 48k even means "I'm a charger > and I can do *2*(!)A", just GTA02 can't take more than 1A. This might change > for GTA0x!) > > HTH > cheers > your friendly engineer jOERG _______________________________________________ Openmoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
