RA8875 bitmaps

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StanDe
 
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RA8875 bitmaps

Post by StanDe »

Hello,

I am working on a project where I would like to display images/bitmaps? on a screen. After doing some research the easiest thing to do seems to be to get the RA8875 with a 7" display and an Arduino of some sorts. But I am worried that loading the bitmap might take to long (it's for little kids). I would like to keep the resulotion to 800x480 if possible. Is there any way around this? I am pretty familiar to the "Arduino way" of coding and would like to stick to that as much as possible. Do i get a Mega or...? Who can help me?

Thanks in advance!
With kind regards,
Stan Degrande

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adafruit_support_mike
 
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Re: RA8875 bitmaps

Post by adafruit_support_mike »

The RA8875 is an SPI device, so all of the pixel color data has to go one bit at a time. For an 800x480 raster, that's about 1 megabyte of data per screen.

The RA8875's maximum clock speed is 20MHz, and at that rate it would take about half a second to load one full screen of pixel data.

The other option is to use a small RasPi, like the model-A or a Zero, and a TFP401 HDMI converter:

https://www.adafruit.com/product/2218

That combination is fast enough for video.

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RChicou
 
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Re: RA8875 bitmaps

Post by RChicou »

Hello,

I am currently trying to stack a RA8875 and an Adafruit "music maker" shield on an UNO.

My goal is to have the music maker play MP3 files as bitmaps appear on my 5.0" TFT (PID 1680).

I have three main questions:
1) Can the RA8875 read from the SD card in the music maker for the bitmap files.
2) What is the recommended pin layout to make the two boards usable? Then achieve the first question?
3) How do I code the RA8875 to display bitmaps? I have not found a clear answer online on how to do so.

Best

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adafruit_support_mike
 
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Re: RA8875 bitmaps

Post by adafruit_support_mike »

Neither the RA8875 nor the Music Maker's VS1053 know how to talk to an SD card directly. The microcontroller has to read data off the SD card and send it to either the RA8875 or the VS1053.

Our RA8875 library is a subclass of our GFX library, which provides graphics primitives, text, and drawing bitmaps. The same code that draws bitmaps on any other display will work with the RA8875.

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