Simple Charger
Pinout :
• 1 + 5 volts @ 500 ma
• 2 Short to pin 3
• 3 Short to pin 2
• 4 200kohm pulldown
• 5 GND
The Short between pin2 and pin3 is detected by a 200kohm pullup resistor on pin3 / d+ and a voltage comparator comparing pin2 and pin3. It seems to be possible to switch this pullup resistor off by software.
Instead of having to do a short between pin 2 and 3, a pullup resistor between pin2 and pin1 (+5Vdc) can be used (50 or 100kOhm).
Fast Charger
Pinout :
• 1 + 5 volts @ 1,250 ma
• 2 Short to pin 3
• 3 short to pin 2
• 4 440kohm pulldown
• 5 GND