HDMI to RGB interface Converter fro LCD Display

Thread Starter

Kyle M 1

Joined Feb 9, 2019
4
I have recently started a project and am using a round 4.21 in 720x720 display and cant find a way of converting from HDMI to RGB interface for the LCD. If you have any boards that would work or anyway i can just use/modify a exciting board on the market or someone i can talk to about this please let me know. Anything is Helpful
Here is a link to the datasheet for the display.
https://drive.google.com/file/d/15OzodyILr0LROBNJlj5ouSnHjpNvs3Fj/view?usp=sharing
 

ronsimpson

Joined Oct 7, 2019
170
Do you have a HDMI output that is in a 720x720 format? My windows computer can't make that.
I did not look at details. I have used boards like this. It converts DHMI to TTL. It will not change the timing or resolution. You must have the video in 720x720 mode.
1572027386769.png
 
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Thread Starter

Kyle M 1

Joined Feb 9, 2019
4
Do you have a HDMI output that is in a 720x720 format? My windows computer can't make that.
I did not look at details. I have used boards like this. It converts DHMI to TTL. It will not change the timing or resolution. You must have the video in 720x720 mode.
View attachment 189696
So what your saying is if i were to change the resolution output on my raspberry pi it will work in theory also the LCD has 45 pins on it
 

ronsimpson

Joined Oct 7, 2019
170
Look at the 40 pin connector on the blue board and you will see the same names as on the 45 pin connector on the LCD. The pin out is not the same.
You will see G0-7 which is the 8 wires for green. B0-7 and R0-7. There should be H, V, Clk. Every thing you need.
The format I think you can control from the Pi.
 

Thread Starter

Kyle M 1

Joined Feb 9, 2019
4
Look at the 40 pin connector on the blue board and you will see the same names as on the 45 pin connector on the LCD. The pin out is not the same.
You will see G0-7 which is the 8 wires for green. B0-7 and R0-7. There should be H, V, Clk. Every thing you need.
The format I think you can control from the Pi.
OK thank you so if i where to convert the 40 pin to the pin out of the 45 pin connector it should work if i scale the output resolution
 

ronsimpson

Joined Oct 7, 2019
170
I don't know how to make the Pi work. Set the size to 720x720 and see what happens. Do you have a way to measure the DCLK? You need it to be +/-10% of 38mhz. It looks like the LDC is pretty forgiving on many of the numbers.
There is a good chance the picture will not be centered horizontally. You may need to play with H-back porch or H-front porch.
1572053711262.png
 
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Thread Starter

Kyle M 1

Joined Feb 9, 2019
4
I don't know how to make the Pi work. Set the size to 720x720 and see what happens. Do you have a way to measure the DCLK? You need it to be +/-10% of 38mhz. It looks like the LDC is pretty forgiving on many of the numbers.
There is a good chance the picture will not be centered horizontally. You may need to play with H-back porch or H-front porch.
View attachment 189706
ok thank you ill try a few different thing when i receive the display
 
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