On 10/12/2010 00:20, RussellMc wrote: >>> The iPhone isn't looking for a "steady voltage", it's looking for a >>> ratio between lines, exactly what using resistors gets you, so the >>> obvious solution? Use resistors. >> Where did you get this information from? > Even if you don't follow Herbert's advice, you could consider using my > already completed Googling of several days ago. > > I provided links to discussion of the IC used, how to use resistors > to set charge rate, circuit diagram of how to use resistors, values to > use to achieve desired result, photo of inside of phone with charging > IC identified, link to data sheet of IC. The data sheet discusses how > the resistor method works and I have pointed out, perhaps several > times, that that information is in the IC data sheet (LTC4066). I seem to recall doing similar too... IIRC, the iPhone4 uses the Dialog part, but it probably works similarly=20 from what I can gather from LadyAdas page and also the Dialog site: http://www.dialog-semiconductor.com/index.php The apple custom PMIC might be similar to this kind of thing: http://www.dialog-semiconductor.com/downloads/Dialog_PB_DA9052.pdf I'd just go with info from the LTC4066, and the info from LadyAda and=20 others, then just try out a few different resistor dividers on the data=20 lines whilst measuring current to figure things out. Previous links from my other mail: I believe they have from what I discovered - I think the iPhone 1 uses an LTC 4066 IC - info here: http://tzywen.com/modules.php?name=3DNews&file=3Darticle&sid=3D696 This page might be of interest from Lady Ada: http://www.ladyada.net/make/mintyboost/icharge.html Seems the Apple stuff can get very picky about the datalines (similar to my Omnia - had to hack a charger for that, would not simply charge from any USB source) needing voltage dividers etc. I also found the iPhone4 uses this power management IC: Dialog D1815A 338S0867 Info from this page: http://www.isuppli.com/Teardowns-Manufacturing-and-Pricing/News/Pages/iPhon= e-4-Carries-Bill-of-Materials-of-187-51-According-to-iSuppli.aspx And this page: http://www.tgdaily.com/hardware-features/50344-the-real-iphone-4-teardown --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .