RaspberryPi/UART
From OER in Education
Powering the Raspberry Pi
The UART connector can also power the Raspberry Pi. However, do not connect two power sources! The two scenarios shown below are alternatives.
RaspberryPi_UART_POWER.JPG
Raspberry Pi B+ powered via UART/serial cable:
RaspberryPi_UART_and_USB_power.JPG
Raspberry Pi B+ connected via UART/serial cable, but powered through USB:
Similar image, for model B from http://elinux.org/RPi_Serial_Connection
RaspberryPi_UART_Ethernet.JPG
In both scenarios above, the ethernet cable can be connected as well. The picture below shows Raspberry Pi B+ connected via UART/serial cable and ethernet cable, powered through USB:
If you remove the USB power supply, you could also power the Raspberry Pi using the red UART cable.