Pulsating sound from inductive coil...Uh-oH!

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pendragon_01
 
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Re: Pulsating sound from inductive coil...Uh-oH!

Post by pendragon_01 »

adafruit_support_bill wrote:The charging protocol depends on the phone. http://en.wikipedia.org/wiki/USB
A portable device can recognize the type of USB port; on a dedicated charging port, the D+ and D− pins are shorted with a resistance not exceeding 200 ohms...
Need a little help to understand this. I checked the resistors that are called for in the minty boost 500mA and 1A configurations. Both total over way over 200 ohms of resistance. Do i use 200ohms of resistance as stated above or the galaxy S3 compatible minty boost resistor configuration (4 resistors on the datalines: two 75K and two 49.9K resistors)?

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adafruit_support_bill
 
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Re: Pulsating sound from inductive coil...Uh-oH!

Post by adafruit_support_bill »

The resistors used in the MintyBoost follow the Apple 'standard'. They do not short the D1 and D2 pins together, they are voltage dividers set the voltage on D1 and D2 to ~2v to keep the iPhones happy..

To emulate a dedicated charging port (the new 'official' USB standard), you simply short D1 and D2 together. (Hint. A simple solder bridge has a resistance "not exceeding 200 ohms").

pendragon_01
 
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Re: Pulsating sound from inductive coil...Uh-oH!

Post by pendragon_01 »

thanks for the pro tip :)

The 'Apple standard' applies to all phones that minty boost is compatible with, correct ?

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adafruit_support_bill
 
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Re: Pulsating sound from inductive coil...Uh-oH!

Post by adafruit_support_bill »

Most phones will work with it, but some do not. In the tutorial we suggest shorting D1/D2 if your phone doesn't get along with the 'Apple Standard'.
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pendragon_01
 
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Re: Pulsating sound from inductive coil...Uh-oH!

Post by pendragon_01 »

Thanks for the great direction! android ftw!

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