swit / gpihdmiout

Enable HDMI output on a GPi Case with a Raspberry Pi Zero or Zero 2 running Retropie.

gpihdmiout

Use these scripts at your own risk. These scripts enable HDMI output on the Retroflag GPi Case running a Raspberry Pi Zero 1 or Zero 2 and Retropie. You will need to cut a hole in the GPi Case Cartridge. The HDMI output and LCD screen CAN NOT both be enabled at the same time. The setup instructions will add a Retropie menu option to Enable and Disable HDMI after powering off. If a HDMI cable is not detected on boot the script will disable HDMI, enable the LCD, and reboot. This can take 30-60 seconds on a RPiZ2.

WARNING: Do not enable HDMI without completely powering off the GPi Case afterwards. Do not use "sudo reboot" or "sudo poweroff". Doing so may leave junk displayed on the GPi's LCD screen that can BURN INTO THE SCREEN after only a few minutes. I know this. I did this. The burned in pattern went away after several hours of the unit resting at room temperature. I got lucky.

Setup

Download and install the GPiCASE patch from https://support.retroflag.com/

Enabling HDMI overwrites /boot/config.txt with /boot/GPi_Case_patch/original_files/config.txt. Disabling HDMI overwrites /boot/config.txt with /boot/GPi_Case_patch/patch_files/config.txt. Make any needed changes to /boot/config.txt and /boot/GPi_Case_patch/patch_files/config.txt or /boot/GPi_Case_patch/original_files/config.txt like overclocking or audio fixes for RPiZ2.

Clone the HDMI output scripts into /home/pi

$ cd /home/pi
$ git clone https://github.com/SWiT/gpihdmiout.git

Add the HDMI detection script to rc.local before "exit 0" line.

$ sudo nano /etc/rc.local

    sudo /home/pi/gpihdmiout/detect.sh

Add Retropie menu option to Enable and Disable HDMI.

$ ln -s /home/pi/gpihdmiout/toggle.sh /home/pi/RetroPie/retropiemenu/"HDMI Output Enable & Disable.sh"

Restart the GPi Case and you are done.

gpihdmiout's Issues

Pi Zero 2 Sound

This breaks sound through the case with a Zero 2 After Using it due to the audio config being different between the two devices

detect.sh issue with Raspberry Pi Zero 2

I recently got a Zero 2 running in my GPi Case: The enable and disable scripts work on it but detect.sh couldn't tell when the HDMI cable was disconnected on boot after enabling HDMI out:

The Zero 2 reports a value of 0x40000 for the $TVCODE variable Line 25 elifs against rather than 0x40001: Changing the value allows the script to work as expected.

Check support for lower resolutions.

The RPi Zero 1 & 2 automatically selects 1080p60 for HDMI out. What if an old monitor or config.txt forces 1080p30, 720p60, or 720p30? There may be performance advantages to supporting lower resolutions and refresh rates.