Hello,
I am currently engaged in the design of a CM4 carrier board and I have a query regarding the implementation of USB OTG. From my understanding, the OTG pin determines whether the Pi functions as a USB device, a functionality used for flashing the eMMC when the eMMC boot pins are shorted.
In my design, I plan to incorporate a switch for shorting the eMMC pins for flashing. Now, I am contemplating whether adding a switch to the OTG port would allow me to utilize the USB port with the Pi as a host after the device has been flashed and is in operation. In summary, I would have two switches serving two use cases:
1. SW1: Shorting the eMMC boot pins and SW2: Connecting the OTG pin to the USB port VBUS for flashing the OS.
2. SW1: Open and SW2: Connecting my 5V to the USB port VBUS, enabling the USB port to function with the Pi as host.
The design would be similar to the IO USB 3.0 board below, but with a single throw double pole switch to alternate between OTG and 5V for the single USB port.
Raspberry Pi Compute Module 4 IO USB 3.0 Board:
https://datasheets.raspberrypi.com/cm4i ... ppnote.pdf
Furthermore, the subsequent question, if this approach is sensible, pertains to whether I can use a type C connector and the implications this has on the CC pins.
Thank you
I am currently engaged in the design of a CM4 carrier board and I have a query regarding the implementation of USB OTG. From my understanding, the OTG pin determines whether the Pi functions as a USB device, a functionality used for flashing the eMMC when the eMMC boot pins are shorted.
In my design, I plan to incorporate a switch for shorting the eMMC pins for flashing. Now, I am contemplating whether adding a switch to the OTG port would allow me to utilize the USB port with the Pi as a host after the device has been flashed and is in operation. In summary, I would have two switches serving two use cases:
1. SW1: Shorting the eMMC boot pins and SW2: Connecting the OTG pin to the USB port VBUS for flashing the OS.
2. SW1: Open and SW2: Connecting my 5V to the USB port VBUS, enabling the USB port to function with the Pi as host.
The design would be similar to the IO USB 3.0 board below, but with a single throw double pole switch to alternate between OTG and 5V for the single USB port.
Raspberry Pi Compute Module 4 IO USB 3.0 Board:
https://datasheets.raspberrypi.com/cm4i ... ppnote.pdf
Furthermore, the subsequent question, if this approach is sensible, pertains to whether I can use a type C connector and the implications this has on the CC pins.
Thank you
Statistics: Posted by forlinxembedded — Wed Apr 24, 2024 1:46 am