Archive for augusti 2011

Building charger adapters for our N900s (and other usb-charger-spec following devices)

What do you do when you bought a wall-wart or car charger for your phone, and it doesn’t work due to not following the USB Charger specification*? Well, you could open it and make it follow the spec, or you could build an universal adapter that converts any USB outlet into a dumb charger!

So, we gathered some old USB cables and cut them open. Inside there are four smaller cables, two that carries the actual power coloured red, black, and two that carries data, coloured green and white. So what we did was to solder the green and white together on the end with the female USB connector, and then patch the power lines back with the other (male) end of the cable. And then some shrink tube for stability.

* The USB Charger specification states that a dumb charger should indicate its dumbness by short circuiting the lines used for data.