Composite output problems

[BluRazPi]

Hi all, so I'm new to raspberry pi and have another small but rather irritating problem. When I first got it, I set my pi up with a small 5" composite screen, but have lately been using it on my plasma screen(way more screen real estate!) with HDMI, but now when I go to run it on my 5" screen, I get no display signal whatsoever. I read online a bunch and learned how to tweak the config.txt file, and learned that if the pi doesn't detect HDMI, it should fallback to composite, but it is not doing that lately. Isn't there some way to force composite just like you can force HDMI? By the way, there is no "sdtv-aspect=" line in my config.txt file. Do I just add it to be able to change the aspect ratio? I want be able to set the composite output to 16:9 because my 5" screen is 16:9 ratio(I bought it that way on purpose!).
Any help is greatly appreciated!
BluRazPi

[andrum99]

The Pi originally did detect whether there was anything plugged into the HDMI port and produce its display on the composite port if none was found. (That is the official version. I actually observed that if there was also nothing connected to the composite port at boot time then there would be no output on the composite port either). Since the advent of NOOBS this is no longer the case. If you have NOOBS installed on your Pi you will only get output on the HDMI port, unless you edit the config.txt file.

To force the Pi to output PAL on the composite port, add the following line to /boot/config.txt:

Code: Select all

sdtv_mode=2

To force the aspect ratio to 16:9 add this line:

Code: Select all

sdtv_aspect=3

For more information see http://raspberrypi.stackexchange.com/ta ... g.txt/info

To change the port NOOBS uses to output its display, use the 1, 2, 3 and 4 keys on your keyboard while NOOBS is running (not while it is booting). These select:

1 - HDMI preferred mode
2 - HDMI safe mode
3 - composite PAL
4 - composite NTSC

The Pi can only output to either the HDMI port OR the composite port, not both at the same time.

[FTrevorGowen]

The Pi originally did detect whether there was anything plugged into the HDMI port and produce its display on the composite port if none was found. (That is the official version. I actually observed that if there was also nothing connected to the composite port at boot time then there would be no output on the composite port either). Since the advent of NOOBS this is no longer the case. If you have NOOBS installed on your Pi you will only get output on the HDMI port, unless you edit the config.txt file.
...

Not quite the "whole truth". Editing the config.txt file is only necessary if, having selected one of the composite video modes (key '3' or key '4') when first booting NOOBS (and before installing an O.S.) you choose not to make that (new) video mode "permanent" as shown here:
http://www.cpmspectrepi.webspace.virgin ... ellow.html
(ie. NOOBS always defaults to HDMI unless instructed not to do so)
W.r.t. Raspbian (not installed via NOOBS) falling back to composite video in the absence of an HDMI connection that can still happen so long as the HDMI display/cable combination provides a "hot-plug" signal - the absence of which triggers the "fallback" unless config.txt contains an active (uncommented) "hdmi_force_hotplug=1" line, which forces HDMI output.
Trev.

[BluRazPi]

Hi again, sorry to bother you, but just after I posted the question, I discovered that the NOOBS default settings in the config.txt had a " force HDMI hot-plug" line that wasn't commented. I commented it and bingo, everything seems to be back to normal, the composite output is working, and also, I put in "sdtv-aspect=3" in the config.txt and that also seemed to work! Thank you for the help anyway!
BluRazPi