I recently purchased an Iphone 5, and been thinking about a small portable field charger for it when I do not have access to an outlet, or computer for the USB port.
Before finding Adafruit, and coming across the MintyBoost, I started to rig up my own portable charger using the following:http://www.hobbyking.com/hobbyking/stor ... duct=28650
A two cell LiFEPo battery pack which is a safer chemistry than a Lithium Polymer battery, and wire it up to this:http://www.hobbyking.com/hobbyking/stor ... duct=28248
Voltage regulator which takes 6-23v input to a 5.1v out. I use these to power my servos and receiver separately in my model aircraft.
I cut up and spliced a sacrifical USB cable and simply soldered the power connections and left the two data wires floating.
See photo attached. The thing with the checkerboard was the battery. I took it apart and broke it down to two 3.3v single cells for use with the Mintyboost.
After rigging it up (I have not connected it to the iphone yet), I came across Adafruit and read about the Mintyboost.
Please confirm/correct my understanding as it applies for iphones (iphone 5 specifically):
As a way to ensure the use of Apple only products, they put a voltage divider to the two data pins on the USB connector. If the iphone does not sense a 2 volt (or thereabouts) potential across the two data lines, the iphone will not/should not charge correct?
The iphone obviously charges fine when I plug the lightening cable into the usb port of my computer.
Also, when I purchased this: http://www.bhphotovideo.com/bnh/control ... &A=details
And plug it into my carport, it also charges my iphone just fine.
In order for the MintyBoost to work, it requires a voltage divider on the data pins...why? How does the iphone know the difference between a usb connection to a computer, a car-port-to-usb, or a lithium battery-to-usb setup like the attached photo, or a pre-version 3 MintyBoost?
What am I missing?