USB-OTG-dat
SCH 1
SCH 2
USB OTG/USB TYPE-C
USB-C OTG (On-The-Go) Hardware Requirements
To enable OTG support on a USB-C DIY project, you must signal to the Host (the phone) that it should act as a Master and provide 5V power.
The Wiring:
- Data: Connect D+ and D- pins.
- Power: Connect VBUS and GND.
- OTG Signal: Place a 5.1kΩ resistor between the CC pin and GND.
How it works: 1. The phone detects the 5.1kΩ Pull-down (Rd) on the CC line. 2. The phone's internal controller switches from Sink (receiving power) to Source (providing power). 3. The phone outputs 5V on the VBUS line to power your mouse, keyboard, or MIDI device.
该部分连接到了芯片的DP/DM引脚，为芯片的USB接口。
USB Type-C用于USB Fel模式烧录系统，无供电输入/输出能力。
USB OTG处可用于连接其他USB设备，带5V输出，可用于连接其他USB设备，当然也可以接双头USB Type-A线缆用于USB Fel模式。
该模块原理图如下所示：
需要注意的是，开发板中没有连接ID线（ID线用于识别USB模式），所以在编写设备树时，我们需要强制指定USB模式为主机或从机。
cell phone type-c gadget
