Raspberry Pi Forums

Hello,

I have a problem with my 4.3" display, I got a TRRS to RCA cable and I though I was good to go but I seem to be getting a few problems.

I am trying to build a retropie portable console, here's a video of whats happening with the display: https://youtu.be/Omk4kGXj-TY

After the video I tried to go on /boot/config.txt and change the framebuffers to 480 x 272, enabled sdtv_mode=2 and added hdmi_ignore_hotplug=1 but I still get the same thing, can this be a cable related issue?

Thanks

Gomez wrote:Hello,

I have a problem with my 4.3" display, I got a TRRS to RCA cable and I though I was good to go but I seem to be getting a few problems.

I am trying to build a retropie portable console, here's a video of whats happening with the display: https://youtu.be/Omk4kGXj-TY

After the video I tried to go on /boot/config.txt and change the framebuffers to 480 x 272, enabled sdtv_mode=2 and added hdmi_ignore_hotplug=1 but I still get the same thing, can this be a cable related issue?

Thanks

Did you check that it is a TRRS4 cable correctly wired

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

http://www.modmypi.com/raspberry-pi/acc ... 3-x-rca-3m

fruitoftheloom wrote:

Gomez wrote:Hello,

I have a problem with my 4.3" display, I got a TRRS to RCA cable and I though I was good to go but I seem to be getting a few problems.

I am trying to build a retropie portable console, here's a video of whats happening with the display: https://youtu.be/Omk4kGXj-TY

After the video I tried to go on /boot/config.txt and change the framebuffers to 480 x 272, enabled sdtv_mode=2 and added hdmi_ignore_hotplug=1 but I still get the same thing, can this be a cable related issue?

Thanks

Did you check that it is a TRRS4 cable correctly wired

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

http://www.modmypi.com/raspberry-pi/acc ... 3-x-rca-3m

Oh yeah, I am pretty sure that's the problem, I don't have a multimeter with me atm so I can't check if its wired correctly, can I rewire it if its not correct or do I have to buy one that is compatible? I'm new to building projects so I am sorry if this questions sound stupid ahah

Thanks

edit: I mean, if I connect ANY cable to either white or yellow plug from the display, as long as there is any cable in both of them as it is on the youtube video then I get this weird signal on the display... any cable at all gives me this video so I am pretty sure it is not wired correctly and I either need a new cable or rewire it if its possible.. il test it later when i get my hands on a multimeter at school

The crooked, unstable white bar is a 100% positive indicator that your cable is wired incorrectly. It is swapping video and ground. Your display is getting an inverted signal. That white bar is the horizontal sync pulse which should be blacker than black.

drgeoff wrote:The crooked, unstable white bar is a 100% positive indicator that your cable is wired incorrectly. It is swapping video and ground. Your display is getting an inverted signal. That white bar is the horizontal sync pulse which should be blacker than black.

Thanks for the information sir, is the cable possible to be rewired manually or is it better to buy a proper one for raspberry pi?
Thanks

Gomez wrote:Is the cable possible to be rewired manually or is it better to buy a proper one for raspberry pi?
Thanks

Certainly possible, provided you have the tools and dexterity.
But the end result would probably be unsightly and fragile.

"Better" depends on your circumstances, but for most people, buying the correct cable would be better

Burngate wrote:

Gomez wrote:Is the cable possible to be rewired manually or is it better to buy a proper one for raspberry pi?
Thanks

Certainly possible, provided you have the tools and dexterity.
But the end result would probably be unsightly and fragile.

"Better" depends on your circumstances, but for most people, buying the correct cable would be better

Do you think I can solder the wires directly into the raspberry pi board? which means removing the 3.5mm socket itself? I assume that is possible, not sure, on the final design the screen is supposed to be directly above on the raspberry pi so the cable can't even be long, the shorter it is the better it fits into this case I made on Fusion 360.

image

Can I solder it directly on the board or do I just buy a new cable that works properly and then shorten the cable and just connect usually? I assume this last one is safer but less space-efficient in the case..

Thanks

You can solder directly to the underside of the board without removing the 3.5 mm socket.

drgeoff wrote:You can solder directly to the underside of the board without removing the 3.5 mm socket.

I fixed the jack, I'll try it when I get home but I'm pretty sure it's working, it is looking good at least.

http://m.imgur.com/4h9e4KL,GnXKQgB

It is working, I will maybe solder the wires directly to the bottom of the board later, but in testing stages where I am still configuring gpio buttons and other kinds of stuff this is good enough, here's a video ^^

https://www.youtube.com/watch?v=R9VEwJh ... e=youtu.be

Gomez wrote:
It is working
https://www.youtube.com/watch?v=R9VEwJh ... e=youtu.be

Better than I expected. To quote someone else: Not just Good, but Good Enough!

Next time you upload a video, could you clean the lens? There's a splodge of muck just right-of-centre, which annoys the ... out of an ex-broadcast TV engineer

Burngate wrote:

Gomez wrote:
It is working
https://www.youtube.com/watch?v=R9VEwJh ... e=youtu.be

Better than I expected. To quote someone else: Not just Good, but Good Enough!

Next time you upload a video, could you clean the lens? There's a splodge of muck just right-of-centre, which annoys the ... out of an ex-broadcast TV engineer

It is on the inside of the phone's lens, nothing I can do tbh, getting a meizu soon so my next videos will be fine ahah