The Merry Yeoman
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Composite Monitor?

Fri Jul 17, 2015 5:51 pm

Help. I have not been able to get a composite monitor to work. I have nothing but a 3000 lumen projector to hook my hdmi up to. I bought an hdmi to composite (av) adapter cord that I wonder if it even legit.
I was under the impression that the 3.5 mm jack was not only audio but also video output. I have tried 3 different cords (3.5mm to AV [rca]) including a specific one from a certain company that was hyperlinked to me in a forum discussion. None work. I am so very frustrated.
There is a huge learning curve for me to begin with and I can't even spend time on the pi to give it a chance. ( I have waited weeks at a time for these specific cords and can't afford to just buy a new monitor with hdmi. Help.

fruitoftheloom
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Re: Composite Monitor?

Fri Jul 17, 2015 6:00 pm

The Merry Yeoman wrote:Help. I have not been able to get a composite monitor to work. I have nothing but a 3000 lumen projector to hook my hdmi up to. I bought an hdmi to composite (av) adapter cord that I wonder if it even legit.
I was under the impression that the 3.5 mm jack was not only audio but also video output. I have tried 3 different cords (3.5mm to AV [rca]) including a specific one from a certain company that was hyperlinked to me in a forum discussion. None work. I am so very frustrated.
There is a huge learning curve for me to begin with and I can't even spend time on the pi to give it a chance. ( I have waited weeks at a time for these specific cords and can't afford to just buy a new monitor with hdmi. Help.
Yes the B+ / 2B have a TRRS4 AV as per:

http://www.raspberrypi-spy.co.uk/2014/0 ... video-jack

...the cable can be checked with a multimeter
Retired disgracefully.....

Tom_A
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Re: Composite Monitor?

Fri Jul 17, 2015 6:05 pm

Check your /boot/config.txt file to make sure you don't have the setting that forces HDMI. If you have a multi-meter, or even just a low voltage lightbulb and batter, you can test the wiring to make sure that it is wired properly. There a couple different versions of the cable. Some will not work and some have the RCA plugs swapped around so you need to experiment to find where the video and each audio channel is set. I'm guessing that your config file is the problem. I think NOOBS may automatically add the setting to force HDMI output.

The Merry Yeoman
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Re: Composite Monitor?

Fri Jul 17, 2015 6:18 pm

I've tried different (audio) plugs from each one as video in case they were switched. One of them was from a camcorder so maybe that would have had a problem. However this one is titled with "Specialized for pi" why doesn't it work?: http://www.dx.com/p/specified-av-cable- ... alHk_lVikp

would this cord even work for anything?: http://www.lightinthebox.com/hdmi-v1-3- ... aQodmD8C1Q
I bought both of the above cords and neither work for me. Am I doing something wrong?

fruitoftheloom
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Re: Composite Monitor?

Fri Jul 17, 2015 6:50 pm

The Merry Yeoman wrote:I've tried different (audio) plugs from each one as video in case they were switched. One of them was from a camcorder so maybe that would have had a problem. However this one is titled with "Specialized for pi" why doesn't it work?: http://www.dx.com/p/specified-av-cable- ... alHk_lVikp

would this cord even work for anything?: http://www.lightinthebox.com/hdmi-v1-3- ... aQodmD8C1Q
I bought both of the above cords and neither work for me. Am I doing something wrong?
Did you follow above advice :?:
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The Merry Yeoman
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Re: Composite Monitor?

Fri Jul 17, 2015 7:07 pm

If you are talking about using a multimeter, I don't have one. I've never used one. And I've been hunting to find where I may have my pi forcing hdmi But I can't find anything that is a boot config file.... Like I said... I have a lot to learn. Also I thank everyone for your help and I am sorry if I'm getting things out of order in the forum. I'll keep looking for the txt file. I do have noobs

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FTrevorGowen
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Re: Composite Monitor?

Fri Jul 17, 2015 7:10 pm

Tom_A wrote:Check your /boot/config.txt file to make sure you don't have the setting that forces HDMI. If you have a multi-meter, or even just a low voltage lightbulb and batter, you can test the wiring to make sure that it is wired properly. There a couple different versions of the cable. Some will not work and some have the RCA plugs swapped around so you need to experiment to find where the video and each audio channel is set. I'm guessing that your config file is the problem. I think NOOBS may automatically add the setting to force HDMI output.
+1
FWIW, I've used an ex-camcorder video cable with "plugs swapped" on both a B+ and P2B:
http://www.cpmspectrepi.webspace.virgin ... e_Video.29
http://www.cpmspectrepi.webspace.virgin ... lPi2B.html

However, as @Tom_A has already suggested, if you're using a NOOBS-based installation (eg. a pre-installed card) then that will default to HDMI unless you select composite video by pressing/toggling either key '3' or '4' during (first) boot up** and make that option permanent as shown in the second link. The latter also shows how to "fine-tune" the video settings by using NOOBS' built-in editing tool.
Trev.
** or after holding/toggling a 'Shift' during to enter recovery mode. TBH, NOOBS is really intended for use with HDMI TV's or (DVI) monitors. Composite video has always been easier to use via a direct (ie. Raspbian or other O.S. *.img file) install where the O.S. (esp. Raspbian) "falls back" into composite mode if there's no HDMI connection present.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

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rpdom
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Re: Composite Monitor?

Fri Jul 17, 2015 7:10 pm

Can you ssh in to your Pi? If so, what does tvservice -s report?

Code: Select all

# When using composite out, I get this
pi@raspi4:~$ tvservice -s
state 0x80001 [PAL 4:3], 720x576 @ 50.00Hz, interlaced

# When using HDMI to a DVI-D monitor, I get this
pi@raspi5 ~ $ tvservice -s
state 0x120016 [DVI DMT (16) RGB full 4:3], 1024x768 @ 60.00Hz, progressive
If you don't see the first version (could be NTSC instead of PAL) your composite output is not enabled.

fruitoftheloom
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Re: Composite Monitor?

Fri Jul 17, 2015 7:13 pm

The Merry Yeoman wrote:If you are talking about using a multimeter, I don't have one. I've never used one. And I've been hunting to find where I may have my pi forcing hdmi But I can't find anything that is a boot config file.... Like I said... I have a lot to learn. Also I thank everyone for your help and I am sorry if I'm getting things out of order in the forum. I'll keep looking for the txt file. I do have noobs
The NOOBS documentation: https://github.com/raspberrypi/noobs

Note that the output mode selected by the user through pressing one of number keys 1 to 4 (for HDMI preferred, HDMI VGA, Composite PAL and Composite NTSC respectively), will be automatically set in the config.txt files of your installed OSes.
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FTrevorGowen
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Re: Composite Monitor?

Fri Jul 17, 2015 7:14 pm

The Merry Yeoman wrote:If you are talking about using a multimeter, I don't have one. I've never used one. And I've been hunting to find where I may have my pi forcing hdmi But I can't find anything that is a boot config file.... Like I said... I have a lot to learn. Also I thank everyone for your help and I am sorry if I'm getting things out of order in the forum. I'll keep looking for the txt file. I do have noobs
(Our posts crossed)
You may find the full NOOBS documentation informative:
https://github.com/raspberrypi/noobs
(There are also other screenshoots etc. of "the NOOBS process/method etc." for several releases/versions within my webpages (see sig.)
Trev.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

The Merry Yeoman
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Re: Composite Monitor?

Fri Jul 17, 2015 7:25 pm

Still doing my best here. I'm on both computers and reading lots of advice (which I appreciate) and don't understand most of it (Merry Yeoman means "Happy Farmer" so...) I will try to read the noobs hyperlink but still don't understand why this cord wouldn't work: http://www.lightinthebox.com/hdmi-v1-3- ... aQodmD8C1Q if it is forcing hdmi.
Also If I type in '/boot/config.txt' my pi tells me that the specified directory is not valid when I am in my file manager.

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rpdom
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Re: Composite Monitor?

Fri Jul 17, 2015 7:35 pm

That cable will only work if the HDMI output also has an analog composite signal on it. It doesn't contain any electronics to do the real conversion from digital signal to analogue.

The directory is /boot

The file is config.txt in that directory.

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Re: Composite Monitor?

Fri Jul 17, 2015 7:39 pm

The Merry Yeoman wrote:Still doing my best here. I'm on both computers and reading lots of advice (which I appreciate) and don't understand most of it (Merry Yeoman means "Happy Farmer" so...) I will try to read the noobs hyperlink but still don't understand why this cord wouldn't work: http://www.lightinthebox.com/hdmi-v1-3- ... aQodmD8C1Q if it is forcing hdmi.
Also If I type in '/boot/config.txt' my pi tells me that the specified directory is not valid when I am in my file manager.
That cable will never work - it's probably a non-standard cable using an HDMI connector for other purposes. HDMI uses digital signals, composite uses analog signals and active circuitry is needed to convert one to the other.
Trev.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

The Merry Yeoman
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Re: Composite Monitor?

Fri Jul 17, 2015 7:42 pm

Does the pi's HDMI output have an analog composite signal on it?
I am in my directory tree under /boot and there are no files that say config.txt or anything like that.

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Re: Composite Monitor?

Fri Jul 17, 2015 8:06 pm

The Merry Yeoman wrote:Does the pi's HDMI output have an analog composite signal on it?
I am in my directory tree under /boot and there are no files that say config.txt or anything like that.
1) No - composite is only output via the TRRS AV connector instead of HDMI (it's one or the other, you can't have both at the same time)
2) How are you "looking at" /boot eg. from the command line or via a GUI app. and on what computer?
(On the Pi, if logged in via ssh or from the command-line/terminal what does ls -laF /boot report?
Also the output of uname -a may be useful - it will tell us some things about the O.S. version etc.)
Trev.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, A+ and a B2) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm

The Merry Yeoman
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Re: Composite Monitor?

Sat Jul 18, 2015 2:53 am

FTrevorGowen wrote:
The Merry Yeoman wrote:Does the pi's HDMI output have an analog composite signal on it?
I am in my directory tree under /boot and there are no files that say config.txt or anything like that.
1) No - composite is only output via the TRRS AV connector instead of HDMI (it's one or the other, you can't have both at the same time)
2) How are you "looking at" /boot eg. from the command line or via a GUI app. and on what computer?
(On the Pi, if logged in via ssh or from the command-line/terminal what does ls -laF /boot report?
Also the output of uname -a may be useful - it will tell us some things about the O.S. version etc.)
Trev.
Ok, I am excited to be in this position where someone is willing to explain things to me but so far I know:
-O.S. means operating system
-ssh ?
-gui is sometimes pronounced "gooey"
-terminal is where I may be able to code (if I can figure that out)
-what does ls -laF /boot mean? or uname?

... I got into "file manager" on my pi and there was a "directory tree" and /boot was one of the directories. There were many things in the directory, none of which said config.txt

Should I unplug the hdmi so that it has a chance to engage or apply the TRRS?

fruitoftheloom
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Re: Composite Monitor?

Sat Jul 18, 2015 5:13 am

The Merry Yeoman wrote:
FTrevorGowen wrote:
The Merry Yeoman wrote:Does the pi's HDMI output have an analog composite signal on it?
I am in my directory tree under /boot and there are no files that say config.txt or anything like that.
1) No - composite is only output via the TRRS AV connector instead of HDMI (it's one or the other, you can't have both at the same time)
2) How are you "looking at" /boot eg. from the command line or via a GUI app. and on what computer?
(On the Pi, if logged in via ssh or from the command-line/terminal what does ls -laF /boot report?
Also the output of uname -a may be useful - it will tell us some things about the O.S. version etc.)
Trev.
Ok, I am excited to be in this position where someone is willing to explain things to me but so far I know:
-O.S. means operating system
-ssh ?
-gui is sometimes pronounced "gooey"
-terminal is where I may be able to code (if I can figure that out)
-what does ls -laF /boot mean? or uname?

... I got into "file manager" on my pi and there was a "directory tree" and /boot was one of the directories. There were many things in the directory, none of which said config.txt

Should I unplug the hdmi so that it has a chance to engage or apply the TRRS?
As you have used NOOBS to install Raspbian then looking in File Manager is pointless, you were pointed to the NOOBS page where it states how to force Composite Out, but you appear to be ignoring any advice ;)
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rpdom
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Re: Composite Monitor?

Sat Jul 18, 2015 6:09 am

fruitoftheloom wrote:As you have used NOOBS to install Raspbian then looking in File Manager is pointless
Why? The OP said they were using File Manager on the Pi, not on Windows, so it should see the correct /boot - unless it is one of the installs that didn't set up the fstab correctly.

@The Merry Yeoman The terminal is what you get if you click on the LXTerminal icon or select LXTerminal from the menus. You can type commands in that. Can you try this command and show what it gives you, please

Code: Select all

grep boot /etc/fstab
It should give a line that mentions something like /dev/mmcblk0p6 (or is it p5?). If it says /dev/mmcblk0p1 it is wrong (for a NOOBS install) and needs changing.

SSH means Secure SHell and is a way of securely connecting to a Computer from another computer. There is a program for Windows called Putty that provides SSH. SSH will normally give you a text terminal window to use.

"-what does ls -laF /boot mean? or uname?"
They are commands that you would type into your text terminal or SSH session.

The first one is the "ls" command, which is an abbreviation of "list". It is like the DIR command on the Windows/DOS command line. It lists out the files in a directory (folder). The -laF bit are options to that command. -l means "Long listing" (gives more details. -a means "all" (show hidden files as well. Hidden files in Linux are ones that start with a ".", like ".profile"), "-F" means "classify, which means stick a special character on the end to show the file type.

If you type "man ls" in the terminal you will get the full manual, or go here man page for ls.

"uname" gives some basic information about the OS you are running. Mostly what sort of CPU and which kernel version

Code: Select all

pi@raspi2 ~ $ uname -a
Linux raspi2 3.18.11+ #781 PREEMPT Tue Apr 21 18:02:18 BST 2015 armv6l GNU/Linux
pi@raspi2 ~ $ uname -r
3.18.11+
You can see I'm running a "Linux" system, on a machine called "raspi2", the kernel release is "3.18.11+" and the version is "#781 PREEMPT Tue Apr 21 18:02:18 BST 2015". The machine name (hardware/cpu) is "armv6l". The Operating System is "GNU/Linux". man uname for more info. :)

fruitoftheloom
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Re: Composite Monitor?

Sat Jul 18, 2015 6:46 am

NOOBS has its own config.txt editor ;)

Easy Config File Editor

The built-in config file editor allows you to edit the config file of the OS currently highlighted in the OS list. This allows you to easily add license keys to different OS installs through the same interface.

Note that the output mode selected by the user through pressing one of number keys 1 to 4 (for HDMI preferred, HDMI VGA, Composite PAL and Composite NTSC respectively), will be automatically set in the config.txt files of your installed OSes. This means that you shouldn't have to worry about manually changing your display settings to get your installed OS to display correctly on your display device.
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Jednorozec
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Re: Composite Monitor?

Sat Jul 18, 2015 9:44 am

The Merry Yeoman wrote:If you are talking about using a multimeter, I don't have one. I've never used one.
You should get yourself a cheap multimeter. Besides checking your cables you can use it for testing batteries.
The most important leg of a three legged stool is the one that's missing.
It's called thinking. Why don't you try it sometime?

The Merry Yeoman
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Re: Composite Monitor?

Sat Jul 18, 2015 2:02 pm

OK I will try to do that later with the codes in LXTerminal
I don't understand why there is a second code link (maybe just trying to process what the first one means)
OP?
fstab?
addressing ssh - I haven't connected two computers yet. but still I guess the "shell" in LXTerminal?
I'm not ignoring anyone. I have so many new things to learn that I didn't notice I had missed something.
as far as the noobs thing goes... I'm not online with my pi nor on the "ssh" so... it would be knowledge I would learn from this site? Or is it supposed to do something with the computer that reaches the site?
I did get on the site but with no direction on my end it was like narnia with all new friends and enemies.
I'm not trying to be annoying -I just want you to understand who you are talking to and I was marketed into this stuff as if it were designed for children. Bear with me as my children lost interest a while back.

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rpdom
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Re: Composite Monitor?

Sat Jul 18, 2015 5:04 pm

OP means "Original Poster" - The person who started the thread. That's you :)

fstab is a file /etc/fstab which contains a list of devices that contain filesystems and the directories that they will be "mounted" on. It's short for "File System TABle".

Yes, when you connect from one machine to another with SSH (or using a program like "Putty"), you get something like the LXTerminal window to type commands in.

I find the children pick up a lot of the stuff easier than the adults - even the old fogies like me ;)

The Merry Yeoman
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Re: Composite Monitor?

Sun Jul 19, 2015 2:57 am

rpdom wrote:
fruitoftheloom wrote:As you have used NOOBS to install Raspbian then looking in File Manager is pointless
Why? The OP said they were using File Manager on the Pi, not on Windows, so it should see the correct /boot - unless it is one of the installs that didn't set up the fstab correctly.

@The Merry Yeoman The terminal is what you get if you click on the LXTerminal icon or select LXTerminal from the menus. You can type commands in that. Can you try this command and show what it gives you, please

Code: Select all

grep boot /etc/fstab
It should give a line that mentions something like /dev/mmcblk0p6 (or is it p5?). If it says /dev/mmcblk0p1 it is wrong (for a NOOBS install) and needs changing.

In this case it needs changing because it says:
/dev/mmcblk0p1

and on the same line it says /boot vfat defaults 0 2
(to be fair I was roughly estimating the spaces)

I will try to figure out how to change it tonight. However any advice is still greatly appreciated. Thanks for your help!

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rpdom
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Re: Composite Monitor?

Sun Jul 19, 2015 9:25 am

The Merry Yeoman wrote:In this case it needs changing because it says:
/dev/mmcblk0p1

and on the same line it says /boot vfat defaults 0 2
(to be fair I was roughly estimating the spaces)

I will try to figure out how to change it tonight. However any advice is still greatly appreciated. Thanks for your help!
You can change it using "sudo nano /etc/fstab" to get the editor, then make the changes, write out (Ctrl+O), and exit (Ctrl-X). The size of the paces are unimportant, as long as there is at least one space or tab between each field.

You'll need to change it to /dev/mmcblk0p5. Here's another way to do that, without using the editor (or rebooting):

Code: Select all

pi@raspi2 ~ $ grep boot /etc/fstab  # Just to show you what is there now
/dev/mmcblk0p1  /boot           vfat    defaults          	0       2
pi@raspi2 ~ $ sudo umount /boot
pi@raspi2 ~ $ sudo sed -i "s/blk0p1/blk0p5/" /etc/fstab
pi@raspi2 ~ $ grep boot /etc/fstab
/dev/mmcblk0p5  /boot           vfat    defaults          	0       2
pi@raspi2 ~ $ sudo mount /boot
pi@raspi2 ~ $
and now you should see the correct /boot/config.txt file :)

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Re: Composite Monitor?

Mon Jul 20, 2015 4:10 pm

American user here. Do I need to worry about PAL/NTSC regions when planning to use a Raspberry Pi 2 on composite cables?
May I have an internet please? One internet here. Thanks.

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