Designing your own charging circuit for the iPhone, iPod, or iPad? Well, Lady Ada has figured out that you need certain resistor values and more current than normally needed for your iDevices to charge correctly.
We did some experimenting (see the video up top) and determined that in fact the different voltages/resistances did effect the charging rates! Using the 2.8V&2.0V setup resulted in a 1 Amp charge rate and the 2.0V&2.0V setup resulted in a 500mA charge rate.
This made us very happy, because 500mA is within the capability of the MintyBoost chip. We redesigned the PCB to allow us to have 4 resistors on the datalines and put two 75K and two 49.9K resistors in each kit. So far we have had no problems charging any of the latest Apple devices. Hooray!
Now you can happily start hacking up your own Minty Boosts!