I2C Extender for VU7C screen

[zyssai]

Edit: Added purchase link at the end of the post

Hi,

If you are using VU7C with ribbon cable (especially more that 3ft), and you are facing this issue:



Or this one:


This is probably due to I2C bus specifications, more information from my friend mctom here, thanks to him.
So to prevent this, we can use LTC4311 chip to enhance data transmission speed and reliability for I2C bus.

Here is signal with and without use of LTC4311 chip:


I have designed a small pcb board, to fit between VU7C screen and N2.
3D model of header is false, pins are longer in reality.





Edit:
Project is done.
Purchase is available here.

[zyssai]

Thank you for sharing a nice solution.

[zyssai]

I have received some PCB pieces.





I will solder components this week and will test it

[mctom]

I suggest you only solder pins that are in use, so the remaining pins will be more flexible and make easier fit to a female IDC connector on a cable.
Lust a loose idea.

[zyssai]

I suggest you only solder pins that are in use, so the remaining pins will be more flexible and make easier fit to a female IDC connector on a cable.
Lust a loose idea.

Thanks

For the first try I soldered all the pins, there is no alignment problem, as long as header comes without bent pins.




Here it is mounted on VU7C



Here, directly on top of N2.


I think I can choose a smaller header. This one have pins of 11mm long.

Unfortunately, I tried but cannot reproduce bad behavior, so I can't confirm for the moment that it works.
But it should, as this is the same schematic as GPIO'4'Cars project, and since I mounted LTC4311 chip on it, I never faced it anymore.

[mctom]

Excellent work! And even such a simple PCB teaches you something new, right?

If you're looking for another thing worth improving, try using less solder for each joint.
Adding more solder doesn't improve electrical or mechanical reliability, but may cause errors that are hard to see later on.
Solder joints on N2+ board below are perfect, but also done by machines and different technique. Nevertheless, this is what we're all trying to achieve when hand soldering.

[zyssai]

You are right. Because of sunlight, I did not clearly saw that solder goes up to the pins, so for the next, I will take care of this