Hi
I am trying to use a tft rgb lcd from focuslcd. It has st7701s controller without ram, i am trying to get it display some line at specific rows, however the rows are getting spread vertically forming bands.
I am using vsync and hsync, generated from a psoc device.
Regards
Ajay Sharma
I moved your topic to an appropriate forum category @contactmeajay .
In the future, please take some time to pick the forum category that best suits the subject of your topic. There is an "About the _____ category" topic at the top of each category that explains its purpose.
This is an important part of responsible forum usage, as explained in the "How to get the best out of this forum" guide. The guide contains a lot of other useful information. Please read it.
Thanks in advance for your cooperation.
Thankyou, i will take care.
Regards
Ajay Sharma
You are asking for trouble with that sort of display. It means that you have to be constantly refreshing the display to see anything. This is going to eat up a lot of processing time. Also if you loose synchronization, like it looks you have done, this is what you get.
What sort of Arduino do you have?
Maybe it is not fast enough to do the data transfer you need to do.
I would advise you to use a display with its own ram so that you only need to transfer the data when the screen changes.
Hi,
Thanks for taking time to consider the issue.
You are right that controller with ram will have no such issue. I have infact one already.
But i had to lock on to this lcd due to its operable temp range and size.
The st7701s(the one wothout ram) controller is infact been used by many other tft lcd manufacturer as well.
This is being signaled by a psoc, with toggling the gpios using the lcdcontroller interface available as design component. The 24 bit R,G,B line gpios are just kept permanently at 00,00,FF.
I am infact refreshing the display at some 60 fps, the timings of vsync, hsync and pixel clock all verified to be ok on oscilloscope.
Your concern regarding syncronization is infact the only reason that i can figure out, but sync part is already verified with signals on mso and the settings programmed in st7701, for horiz, vert porch, display lines etc.
Regards
Ajay Sharma
I was able to solve the issue. The problem was in the initialisation code. Intact I contacted the lcd manufacturer for the initialisation code.
More surprising was that some register settings were missing from the data sheet itself, of the ST7701S controller.
Regards
Ajay
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