FFC connectors from HDMI to screen?

[Luis11172]

Hi, Have a question about this.. (kinda really confuses the hell out of me tbh and i don't know how to explain it :I)
i have a raspberry pi project I'm trying to fit into a gameboy sp case.
I'm currently trying to find a screen for this project and hoping that this screen would work using ffc connectors

https://www.ebay.com.au/itm/3-5-inch-480x320-Raspberry-Pi-2-3-B-Touch-Screen-HDMI-LCD-Display-Monitor/253941884501?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=56117&meid=90349043e9464339a967faa1795d430c&pid=100675&rk=3&rkt=15&sd=322563102032&itm=253941884501&_trksid=p2481888.c100675.m4236&_trkparms=pageci:d7554297-530d-11e9-984a-74dbd1806a4a|parentrq:cf8f0c2e1690ad4a860d9160ffecf305|iid:1

but here is my main problem
because of the size of the SP i would need to use ffc connectors/cables (sry if they have another name, i only know them as this)

but if i were to de-solder the hdmi connector from the boards and replace it with ffc connectors? would it work...

i was kinda floating around the internet trying to find out information i need to help me with this.. (originally i was looking at just using the normal hdmi connectors. I brought the male connectors, which never arrived... -_- but couldn't figure out how to connect it to each other even if i did have them)

this when a came across a unanswered old thread on sudomod about about the ffc cables?

and then another page saying does it need a mirrored ffc flex cable @-@ (at this point i didn't even know wth i was doing?)

ummmmm... i guess my question is can someone help me and if this would work how could i get it to?

* EDIT *
kept searching HDMI to HDMI mini pin-out didn't realise adding a c would help
well judging from those numbers -_- rip...

*EDIT*
:I i think i need something like this^^^? but unsure in how to make it ._. cause board in picture isn't crossing one another on the pin just extending the cable :I?

I can't figure how to use any software to attempt making something this... :I
so I just seen the adaptor above randomly looking up rpi's and was think this might work if i cut it up and add them ffc things to it. -_- providing there is some sort of board it in

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*parts list for gameboy :I let me know if im using something to crappy (unrelated to topic??)

screen - MPI3508 3.5 inch 480x320 Raspberry Pi hdmi lcd (haven't brought yet, but seems the way to go)
sound AMP - PAM8403 Amplifier (seems to be default for pi users.... but confused on it also, as this is dual channel and i will only be using mono, and read they break if not on both channels.. something about a resistor, does anyone know what kind i would need? to bridge one of the channels?)
game controller - Arduino micro
battery charger - TP4056 (i know this is probably a bad choice of a charger but it was what i could afford at the time of starting this project :I i can upgrade it now if needed?
battery - ds lite cell (doesn't fit in the battery compartment properly, blocks the battery cover)
speaker - from samsung phone
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[ahrlad]

There are lots of mini-HDMI adapter-ffc connector thingies available since drone people use them:

https://www.aliexpress.com/item/FPV...Ribbon-Flat-HDMI-Cable-Pitch/32948003892.html

I wouldn't try desoldering the hdmi connectors, the traces are too tiny and easily broken

 

[ahrlad]

I dunno much about the PAM8403 but it doesn't seem to support bridge tied loads. Maybe try the PAM8302, that does mono and is also cheaply available on chinese modules?

afaik the tp4056 is a very reliable charger chip, it's just not very effective and not very fast since it's limited to 1A charging current. It also doesn't do voltage boosting so you'll need to make sure your stuff runs on only 3v or so. Maybe get a charge module that does buck/boost to 5v instead, there are lots of cheap modules doing that too.

If you really want to make it as thin as possible, you might want to check out cutting out the lcd driving board entirely. the rpi can output dpi (parallel rgb/ttl) natively, so you only need a backlight driver to make the pixels happen

 

[Luis11172]

yea i was an idiot thinking i could use an ffc port on a raspberry pi zero ... =-= since it is a smaller connector so yea ^ i definitely need to buy that mini adaptor, cheers for the link and info on the charger

yea but i read it's a bit laggy on frames?? I am making a couple of them so i guess ill try both ways ^ tho this one will be messy inside. there is a github that has a full tutorial on how to make one with a dpi screen ._. even a printable Gerber which is really nice

 

[ahrlad]

I don't think dpi could introduce lag even theoretically, it's just configuring the board to pump out raw pixels to the screen in real time. Perhaps they were talking about the SPI interface which is another issue entirely, in that case the display has its own frame buffer which introduces some lag depending on resolution and stuff

 

[RoyalBidoof]

Depending upon the protocol, application, overhead, and available computational power, Raspberry Pis can indeed drive their own displays directly. However, this can cause performance laggs when doing more intensive applications like video games. I remember that the old SPI lcds that can be found on ebay and amazon, though cheap, are notorious for this because they used the SPI bus on the GPIO. New methods drive LCDs directly using an FCC adapter, but I haven't looked into the efficacy of this yet with the lag question. A surefire way of avoiding lag is to use the internal Raspberry Pi HDMI. The LCDS with both HDMI and a GPIO header are using the HDMI for video and the GPIO, along with some special software, to drive a resistive touch display. You can remove the GPIO header, carefully using a dremel to knock it down and then a soldering iron to remove the remaining plastic and pins, and the HDMI will drive the display nicely. Trying to slim down the arrangement more by desoldering the HDMI is possible, but extremely difficult. It is possible to use 32 guage magnet wire to wire a Raspberry Pi 3 to and HDMI LCD direcly (I did that; I also don't recommend it) but the wires can easily come off of the pads if care is not taken to have them stay in place. Ultimately, removing the HDMI connectors removes so little additional height, particularly when gluing down the replacement wire and when a heatsink is still needed for the PI CPU that its much better to use male connectors instead. Meaning, one would acquire some male HDMI connectors by opening a cheap cable, place them into the LCD and the PI with the LCD and the PI arranged roughly where they will be in the final case, measuring the necessary wire length between the two, and then wiring up the male connectors to each other using magnet wire. This is extremely easier just because of the pad size on the male connector! Not every HDMI pin needs to be wired. Some pins are unused by the LCDS and with how short the new 'cable' would be you don't need to wire the Shield pins up either.

Hope that helps!

 

[Fruity_Grebbles]

I mean, this guy did it:
Seems viable, if tough. If you trust your soldering, hey, why not? You'd get to avoid a whole HDMI connector hanging off the board.

Edit: oh. Pi zero. Umm..... Maybe not then? Much finer pitch on the HDMI iirc

 

[Notjohnny]

I guess you dont have enough space but you could put the driver board on the bottom half and run a FCC extender to the lcd itself. That way you don't have to worry about connecting the HDMI properly (maybe some random seller has a U shaped HDMI mini to HDMI?)

 

[KaraPelosi]

Hi...HDMI works at 40-50MHz++ at this frequency level signal, tracks layout and parasitic capacitance from soldering have a big impact on signal quality.
Take a look on RPi board, and check how the tracks are formed for HDMI or camera connector, they got even "zig-zags" to compensate for tracks length (to make both tracks of pair equal in length).

turnkey prototype assembly