>> My Blackberry 9530 Storm . will charge it's battery via the USB port >> when I use a >> Kensington power adapter which has a USB port. The BB will also >> charge with it's supplied USB charger. >> I built my own USB power adapter which supplies 5V to the correct >> pins. The Blackberry does not charge. The only difference I can >> imagine is that the data + and - lines make some difference. My >> adapter leaves these lines unconnected. I don't know what the >> Kensington does. I have measured the 5V and it looks okay when loaded. >I know that some Motorola phones use a non-standard connection > (there's an extra resistor in the USB connector) so perhaps the storm > does something similar? I know there's a bunch of info on Google about > the Motorola. The early Motorola Razrs had a resistor on the extra pin provided in the microUSB standard. This served to tell the phone that an expensive Motorola charger was being used rather than an equally good one from another source. I understand that later versions do not require that resistor. Gargoyling Razr USB resistor will probably inform you on this. The Blackberry MAY do something similar. Another possibility is that the alternative adaptor does not meet certain unloaded or loaded or slew rate voltage, or loaded current specs. Some phones have complex handshake algorithms when they are first connected to a charger that allows the phone to attempt to determine what capability of charger is connected. Nokia have a published 2mm charging plug spec, and a range of Nokia phones seem to have a range of expectations that do not match what the spec says. Ask me how I know :-). Many phones will tolerate an input that provides 150 - 200 mA starting at about 5.1V and drooping into the 4.5 - 5V range at the maximum allowed current. Some few demand currents of 300 mA + to charge at all. Some phones will indicate that they are charging when presented with a low capacity charger but don't seem to actually charge usefully. Nokia phones (all 2mm plug and some older) have two modes with choice being n\made at startup based on Vin at a specified light load. Above a threshold and they assume up to 900 mA capability. Below a threshold and the device is deemed to be an 'auxilliary charger' and may run at low or even no current ine\termittently. this is to allow eg hand cranked and other low energy sources to be used. My experience has been that this http://sw.nokia.com/id/3378ff2b-4016-42b9-9118-d59e4313a521/Nokia_2-mm_DC_Charging_Interface_Specification_v1_2_en.pdf seems to be honoured as much in the breach as the observance BUT it gives a useful idea of what goes on "under the hood", even if the actual values vary. And you thought you just plugged in 5V and it "just worked" :-). My experience has been that if you provide a voltage of perhaps slightly above 5V OC with 'enough'; current capability but not too much, then most phones (Nokia and other) will work with it. If you provide too much current capability (900 mA for Nokia) some phones will shut down after a brief trial period. Others probably just emit smoke of various colours. It is a good idea [tm] if your charger droops to below about 4.2V when load is too heavy as many phones provide a fairly direct path between charger input and the internal LiIon battery. Providing LiIon batteries with a stiff high capacity 5V source can be fun and even exciting but is not usually recommended. You would hope that most devices would manage the input at least well enough to shut down in a controlled manner when chargers were over enthusiastic. I have seen one phone that got 'quite upset' under those circumstances (but didn't die). A new "micro USB" universal charging standard is in the process of introduction so a much greater degree of standardisation an be expected a few years from now. Russell McMahon Applied Technology ltd New Zealand. > > Cheers, > -Neil. > > > Quoting YES NOPE9 : > >> >> Any ideas ? >> >> Gus >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > > > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist