Hello, BitTech community. It has been AGES since my last post…that’s mostly because I haven’t had a hardware problem that I couldn’t solve myself. I am posting here because I have a couple of questions about my next ‘mini project’. But first, some background. I recently acquired a blackberry pearl 8100 for rather cheap. One condition of the low price point was that the phone was OEM. No drivers, no cables, and most importantly, no charger. No matter, I though, I can always use a USB port. Wrong! The blackberry will not charge unless the drivers are installed, and most importantly, the pc is *fully powered*. I want to make a cable that I can charge with via PC or wall wart, but I am not sure how this is done. http://pinouts.ru/PDA/pda_miniusb_pinout.shtml and http://www.blackberryforums.com.au/...on/1401-cracked-usb-charging-no-driver-s.html have different ideas about how I the blackberry charger works. I don’t fully understand what the drivers do, but I think they detect the blackberry and *force* the port to output the full 500ma. This becomes a problem, because I cannot always keep my desktop on…or turn it on when I need to charge my blackberry. I have done other reading, and it seems that traditional ‘usb’ wall warts do not work with the blackberry, as they just output 5v @ 500ma on pins 1 and 4. The URL below says that I need to create a special cable with a resistor between the Vcc and D- pins. I guestimate that the resistor puts about 3 volts on the D- pin and causes the blackberry accept the charge. http://www.blackberryforums.com.au/...on/1401-cracked-usb-charging-no-driver-s.html Here is my question: Does anybody know, for certain, what the blackberry charger does to make the blackberry charge? If somebody has a charger they are willing to probe w/ a multimeter I would be incredibly grateful. Because the USB cable I am using to charge my device only has 4 pins (5, actually..but only 4 wires), I believe that the driver somehow sends a signal to the BB (probably by putting ~ 3 volts on D-). Can somebody verify this? And, how, might the blackberry charge *and* allow data communications if there is a constant 3 volt charge on the negative data pin? My ultimate goal, depending on what information I can gather, is to make a simple cable that can power the blackberry two different ways. A “stock” mode, that is nothing more than an unmodified cable for use on computers with the drivers installed. AND, a ‘wall wart’ mode that will allow the use of wall warts or driverless PC’s to charge the blackberry. Additionally, I plan to leave the data lines intact for the ‘stealth’ mode…maybe even the ‘wall wart’ mode. ANY. And ALL help would be GREATLY appreciated! Thanks sooo much.
Solved... Well, I got tired of waiting… so I did more reading / thinking/ experimenting… Here is what I found out. To the best of my knowledge, the blackberry drivers force additional voltage to flow out the Data pins. My 8100 would not charge unless I had connected the RED (power) to the Green AND White (data). This doesn’t explain how the blackberry is able to maintain data functions and charge, but at least I know what must happen for the blackberry to accept a charge from a wallwart. Below is a (badly drawn) schematic of my cable. I put the switch into an altoids tin so that when the cable is not in use, the whole thing can be kept inside the altoids tin. It packs up quite nicely so I can keep it in my bag when traveling… This schematic will create a cable that can act as a normal USB cable AND as a blackberry charger for wall warts and ‘normal pcs’. The DPDT switch is, by my testing, essential. Switch the data lines into normal operation for use as a standard USB cable for PCs that have the BB drivers installed. Switch the 5+ into the data circuits for use with a wall wart charger, or any PC that does not have the drivers installed. - Cheers! And I hope this helps somebody!
Hi, You seem to be working hard for solution which probably going to be easier to fix by getting a second hand charger from Ebay! I have a Blackberry pearl 8100 from a friend and did'nt realise you needed the drivers installed to charge it! Thanks for all your hard work by the way, it is appreciated. You are are far too clever
I found your post very interesting as I was looking to do something similar - also I found these instructions while searching http://www.instructables.com/id/How-To-Make-Your-Own-USB-Car-Charger-For-Any-iPod-/ thanks for the info
