Ok, this IC seems to fit the bill for a single ended to differential HDMI line driver:

https://www.ti.com/lit/ds/symlink/ds90lv047a.pdf?ts=1726209882189

It is low cost and LCSC currently shows some stock:

https://www.lcsc.com/search?q=ds90lv047a

It's even available on a handy (but expensive) break-out board.  The board is intended for I2S over HDMI cable, but the pin-outs seem to match what we need (I had to look at multiple listings to even figure out what the connections are):

https://www.ebay.com/itm/354879832003

Caution:  The breakout boards seem to be available in both "Transmit" and "Receive" versions!  Some of the sellers don't even seem to know what they are offering.  I believe that the Transmit version is what I need for testing, but the listings are somewhat confusing.  When I get it all sorted, I will likely order a board for some initial testing.


Edit:  Now I am seeing that this IC is designed for differential voltage output of only 300mV.  Perhaps not as interesting as I thought.
Edited 2024-09-14 03:55 by Sasquatch

  Bleep said  

Here is the version of Bubble that will work on the 2350.
It is calculating and updating 2700 points at around 4Hz.
I haven't attempted any optimisation for the 2350; yet.
bubble2350.bas.zip

very colourful and fast but how to make it circular?
'calculate centre and scale factor
xc=MM.HRes\2-10:yc=MM.VRes\2
xs=MM.HRes\5:ys=MM.VRes\5

I've just tried again, this time with 5V on the HDMI. My monitor goes into widescreen but synch isn't quite right. The image starts to jump after a few seconds. Do I need any other excuses to buy a new monitor?


:)

Hi Mick,
Did you see Carl's post I was going to give this a try tomorrow hopefully.
Regards Kevin.

Yep. As I've said though, I have no trouble using widescreen mode on a TV. There can't be much wrong with the signal. However, this monitor is a bit of an unknown when it comes to anything apart from bog standard HDMI modes. It might be that this is 50R and the TV is 60R - I dunno. I've no intention of messing up the PCB traces at this point anyway. No point as I've no control over whatever is already on the Pico 2.

As a matter of interest, Alpha isn't using a breakout board. It's a normal HDMI socket.

  Mixtel90 said  

I've just tried again, this time with 5V on the HDMI. My monitor goes into widescreen but synch isn't quite right. The image starts to jump after a few seconds. Do I need any other excuses to buy a new monitor?


:)

no, go to currys and get ripped off
there's tv with 1080 hdmi and an old one will have vga.scart,phono video
yours should work with pico hdmi some way . what is it?

is it a pc monitor? with hdmi or dvi?

The TV is used as such upstairs. My monitor is in the living room downstairs. I'd swap them over but the TV is too big.

The monitor is an AOC with two HDMIs and a VGA. It was an ebay buy just as my last one was dying and I was getting desperate. :) I have another monitor I can try but it's in a bit of an awkward position until my son moves out in a couple of weeks. I think that has DVI and VGA inputs IIRC.

only my olimex 2350 pico2 has hdmi but syncs fine on tvs with hdmi.
never seen dvi on a tv, only hp pc monitors.
never seen hdmi on pc monitor only vga.
tried a different hdmi source to test the monitor? if it works then why pico hdmi not working?