The CPi-G series panel PCs have a 26-pin header socket on the rear panel with the following pinout.

See pp.11 ~ pp.12 of the Compute Module 5 datasheet for more information.

The GPIO pins are not exposed through a level shifter like the CPi-S panel PCs, the internal pull-up/-down resistors can be utilized. GPIO39 has a 1.8kohm pullup resistor to 3.3V because it is initially used for I2C.

The 5V pins can supply a maximum current of 1A. The 3.3V pins can supply a maximum current of 700mA. If both 5V and 3.3V rail pins are used simultaneously, their total power should be kept below 5 watts.

The panel PC's RTC is connected to I2C1, so those pins assigned to I2C1 should not be reconfigured.

The right panel of the CPi-G panel PCs expose a MicroSD card slot, stereo audio output jack, and USB-C console port. (/dev/ttyAMA0)

For models with an eMMC, the MicroSD card slot is not electrically connected, so it cannot be used.

The underside of the CPi-G exposes 12~24VDC power input, 1 RS-232 serial port, 1 RS-485 serial port, 1 USB 2.0 port, 2 USB 3.0 ports, and an RJ45 1Gbps Ethernet port.

The USB device port dedicated to programming the Compute Module's eMMC.