Back in the days when I was more adventurous with my Infuse 4g, I put together a little project board that allows me to specify resistances between pins 4 and 5 of a Micro-B USB cable. This allowed me to force my phone into Car Dock mode, or act as a USB JIG (for Triangle-Away purposes), or even connect to the phone using UART. I have a TTL 3.3v level conversion on the other end (a nice little FTDI breakout board that provides a USB serial port), and that makes it simple to capture the output of UART while the phone boots. I’ve used this board on my Infuse, my Galaxy S2, and now my new Galaxy S4.
To get it to work this time, I had to connect the RxD, TxD, VCC and GND wires up like usual to the FTDI breakout board, but I had to attach the 619k resistance at a specific timing. Here’s the order:
Attached is the UART output from this. Many thanks to AdamOutler and his help with the previous generations of Samsung devices. Hope this somehow helps in the efforts to obtain root. Let me know if there's anything special you'd like me to try.
To get it to work this time, I had to connect the RxD, TxD, VCC and GND wires up like usual to the FTDI breakout board, but I had to attach the 619k resistance at a specific timing. Here’s the order:
- Unplug battery
- Attach MicroB cable to phone
- Attach the 4 wires above (easy for me, with dip switches for each)
- Attach battery
- Start Putty
- Attach 619k resistance between 4th/5th pins.
- Watch the magic
Attached is the UART output from this. Many thanks to AdamOutler and his help with the previous generations of Samsung devices. Hope this somehow helps in the efforts to obtain root. Let me know if there's anything special you'd like me to try.
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