[arm-allstar] HDMI and the PI

[Don Backstrom - AA7AU]

On Fri 09-Feb-18 10:33, "Ken via arm-allstar" wrote:
> On a related note:  for any HDMI display - it seems that if you connect 
> the display after the RPI is up and running, it is not recognized.  It’s 
> as if the DHMI port is turned off.

	In normal config, if the HDMI is not detected during power-up, the Pi 
defaults back to standard video out.

> Is there some option or setting that 
> can force the HDMI port to be “on” or to recognize that something has 
> been plugged in?

	Add these two lines to /boot/config.txt and re-reboot:

hdmi_force_hotplug=1
hdmi_drive=2

Note: config.txt is read by the GPU so it should work on every distro, 
however I haven't tested it on ArchLinux. Works great on Rasparian etc.

hdmi_force_hotplug=1 sets the Pi to use HDMI mode even if no HDMI 
monitor is detected at power-up.

hdmi_drive=2 sets the Pi to normal HDMI mode (Sound will be sent if 
supported and enabled). Without this line, the Pi would switch to DVI 
(with no audio) mode by default.

	- Don - AA7AU