Retroflag GPi 2 with Dock (CE08464)

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Travel back to the Retro days with the GPi 2 case, grab a CM4 and start playing the classics!

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We’ve found there are a few common pitfalls when setting up the GPi 2 case so here’s a quick step-by-step process and the symptoms of common issues.

  1. Flash your SD card using Raspberry Pi Imager with your choice of Recalbox or RetroPie (found in the Emulation and game OS submenu). Choose the Pi4/400 version as it’s most similar to the CM4.

  2. Download the GPi 2 display patch from Retroflag’s website or the link below.
    This patch causes the display to default to the GPi 2 LCD instead of HDMI

  3. unzip the patch and follow the instructions in the readme file which are:

  • copy the folder matching your OS image into the root directory of your SD card
  • open the patch folder on the SD card and run install_patch.bat
  1. You can now fit the SD card to the GPi 2 case, the top of the SD card holder swings out from the PCB. Slide it down slightly to unlock, add your SD card then press gently and slide up to lock the SD in place.

  2. Fit your CM4 to the GPi 2 case by orienting it to match the white trace lines with the component clusters on the CM4. There are two connectors that need to be pressed in until they lock with the GPi 2 case. The GPi 2 is shown with the back case removed below for better visibility of the outlines and connectors.

  3. You can now boot up the GPi 2 and install the safe shutdown scripts using the instructions found here GitHub - RetroFlag/GPiCase2-Script: RetroFlag GPiCase 2 CM4 Safeshutdown with automatically switch LCD and HDMI display script

Common issues:

Symptom: No display on GPi 2 LCD
Cause: GPi 2 patch is not installed, or CM4 connectors may not be fully seated.

Symptom: No response from GPi 2 at all, backlight is not lit.
Cause: GPi 2 battery may be flat.

Symptom: GPi 2 display works but doesn’t switch to HDMI when placed into dock
Cause: The HDMI is not hot-swappable on the GPi 2, you need to power the GPi 2 down, fit the dock, then reboot it to use the dock’s HDMI output.

Symptom: Display is rotated sideways and odd white lines on half of display
Cause: GPi 1 patch was installed on GPi 2 case (don’t ask me how I know).