iPhone 4 Charging Not Supported on the this Device

[whyisjake]

I just built the Minty Boost this morning hoping to take it on a backpacking trip to the Tetons this weekend. It is saying that the device is not supported when I plug in my phone. It does however work when I plug in a co workers iPhone 3Gs. The pins are reading five volts/1.92 volts.

Jake

[whyisjake]

Of note, I was using the cable that came with the phone and Energizer alkaline batteries.

[adafruit_support_bill]

It does however work when I plug in a co workers iPhone 3Gs.

That's a switch! Usually the 3Gs are the most finicky to charge.

Are your voltage measurements with the phone plugged in?

[whyisjake]

Are your voltage measurements with the phone plugged in?

I just tested the voltage with it plugged in, and got the same readings.

[adafruit_support_bill]

The 1.92v is slightly low for the data lines. You could try swapping out the 75K resistors for something like 68K to boost that up a bit. But you might want to calibrate your meter against a known voltage first to be sure that is an accurate measurement.

[whyisjake]

Turns out it was a 3G that works, not a 3Gs.

Also, does charge a Droid X. We put in some nickel metal hydride batteries, and that worked...