Ryno4
Posts: 31
Joined: Tue Apr 26, 2016 9:52 pm

Switching between official 7" display and HDMI TV

Fri May 13, 2016 12:56 am

Hi guys.

I recently hooked up one of the official 7" monitors to my pi so I can make it portable. I am struggling to find it how to switch back to HDMI when I am back home.

I have plug the HDMI cable in, and it registers and switches channel, but the picture is just black and the 7" display is still working.

I was wondering if there is a way of regularly switching between the two, or if it could be done automatically (the second part is not essential)

Thanks.

FredRaspb
Posts: 19
Joined: Wed Mar 16, 2016 8:05 am

Re: Switching between official 7" display and HDMI TV

Fri May 13, 2016 6:19 am

Try add "hdmi_force_hotplug=1" to /boot/config.txt and reboot your Raspberry.

It sets the Raspberry to use HDMI mode even if no HDMI monitor is detected, and should go straight to your LCD via HDMI.

I hope this is what you were looking for.

Regards

Ryno4
Posts: 31
Joined: Tue Apr 26, 2016 9:52 pm

Re: Switching between official 7" display and HDMI TV

Fri May 13, 2016 8:36 am

Thanks for the advice.

Just to clarify, I'm connected to the 7inch monitor via the DSI ribbon. I want to connect to my big TV via HDMI when I'm home.

I'll give it a try later on

Thanks again.

DirkS
Posts: 10347
Joined: Tue Jun 19, 2012 9:46 pm
Location: Essex, UK

Re: Switching between official 7" display and HDMI TV

Fri May 13, 2016 10:44 am

AFAIK the only way to switch to HDMI is to add

Code: Select all

ignore_lcd=1
in /boot/config.txt
See viewtopic.php?f=28&t=121591#p846271

User avatar
procount
Posts: 2209
Joined: Thu Jun 27, 2013 12:32 pm
Location: UK

Re: Switching between official 7" display and HDMI TV

Fri May 13, 2016 10:55 am

You can only switch between the touchscreen and HDMI at boot time.
BUT I have added just this functionality to PINN v1.9.2 for someone who requested the same feature.

See the documentation at https://github.com/procount/pinn/blob/m ... igurations

It assumes the DSI is always connected and it will use it. But if you connect a HDMI monitor, it will be detected and used instead, overriding the touchscreen.
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

Ryno4
Posts: 31
Joined: Tue Apr 26, 2016 9:52 pm

Re: Switching between official 7" display and HDMI TV

Fri May 13, 2016 10:03 pm

DirkS wrote:AFAIK the only way to switch to HDMI is to add

Code: Select all

ignore_lcd=1
in /boot/config.txt
See viewtopic.php?f=28&t=121591#p846271

Just to let you know, im doing all of this straight from the pi, i do not have a PC at home.

Say that this worked, how do i switch back to the LCD?

FYI im a noob at coding :?

thanks

User avatar
procount
Posts: 2209
Joined: Thu Jun 27, 2013 12:32 pm
Location: UK

Re: Switching between official 7" display and HDMI TV

Fri May 13, 2016 11:34 pm

If you are doing it manually, just remove the 'ignore_lcd=1' line from config.txt. But do it whilst the HDMI screen is still attached.

If you were using PINN to switch automatically, then just remove the HDMI screen and it will automatically use the LCD again.
PINN - NOOBS with the extras... https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=142574

Ryno4
Posts: 31
Joined: Tue Apr 26, 2016 9:52 pm

Re: Switching between official 7" display and HDMI TV

Sat May 14, 2016 1:44 am

Thanks for the help guys.

So far I've got it working manually, which is ok for now. One issue that has arisen is that the LCD remains active, even though the picture is going through the HDMI.

It either stays black(which I don't mind) or it flashes bright white and throbs in and out of brightness. Is there a way of stopping this?

I've attached this rough video to show what I mean. https://youtu.be/B2_wKHtDJ-c

Thanks

jmorri36
Posts: 3
Joined: Sun May 29, 2016 3:30 am

Re: Switching between official 7" display and HDMI TV

Sun May 29, 2016 3:33 am

It looks like you just need to turn off the backlight. I've done it before, and it's pretty simple, but I don't have the instructions in front of me. A quick google search should pull up the answer.

Kainam
Posts: 1
Joined: Tue Feb 27, 2018 7:55 am

Re: Switching between official 7" display and HDMI TV

Tue Feb 27, 2018 7:59 am

Easy way to do it manually is just to unplug the 5V+ power lead that connects the two PCBs.

A neater way would be to solder in a SPDT switch in line with that power lead and mount it to the case.

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