Michael Shiloh wrote: > Flemming Richter Mikkelsen wrote: >> - Ohh, and a valid charger ID would be a resistance between res_min >> and res_max. >> - Several pins could be probed > > You can only probe the pins that have the appropriate hardware interface > to them. This may be all, but can't be taken for granted. One of the > hardware people can tell us which pins are capable of this, and how you > select which one you want to measure.
there is only one pin to measure. the 'id pin' is pin number 4 directly beneath pin 5 which is gnd. pin 1 is vcc (5V) 2 and 3 are D- and D+ for usb data. thus all pins are 'taken' by standard besides the 'id pin' on gta02 its connected to an adc inside the pmu. details: the id pin is connected directly to pin9 of the pmu (adcin1) in addition to that there is one resistor of 100k(1%) to gnd and one of 39k(1%) to pin8 of the pmu (accsw) now everyone should be able to do the math while looking at the pmu datasheet. ;) motorola chargers have a 200k (pretty exact, shows 200.0 on my not-that-cheap-but-chinese multimeter) resistor to gnd. in addition to that they short D+ and D- to each others (read about that too in some usb-charging-spec), but i think we can ignore that because detecting that would propably quite some hacking if possible at all (dunno the usb-hw-if of the samsung enough) and also not that helpful. i wouldn want to have a 'range' of 'recognized valid resistance' but rather a table.. means * 48k -> moko charger (2A) -> 1A mode * 200k -> motorola charger (550mA) -> 500mA mode * ... if no resistor or short is detected -> if it speaks usb and does enumerate us as 500mA -> 550mA mode if it does not speak usb at all or only enumerates us as 100mA -> 100mA mode the nice thing is: this whole feature doesn't affect the hw going to mp. its a software needs to have more (to be found out) values and fitting modes coded in. the code to measure the pin should be in uboot and kerneldrivers. didn't have a look at both yet. but yes. a nice small (can be console) way to find out the adc value would be practical to build the table of known to be valid chargers. -- Joachim Steiger developer relations/support _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
