RA8875 with image help

Post here about your Arduino projects, get help - for Adafruit customers!

Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.
Locked
User avatar
keaster20
 
Posts: 4
Joined: Sun May 22, 2022 8:17 am

RA8875 with image help

Post by keaster20 »

I'm trying to find out if the imagereader library will work with the RA8875 library to display .bmp images from a SD card.

I have a library that works with jpegs but it's really slow. 100x200 pixel image will take up 5 seconds to display.

Is the imagereader going to load faster? If not then I will just continue to use what I have.

Thanks

User avatar
adafruit_support_mike
 
Posts: 67454
Joined: Thu Feb 11, 2010 2:51 pm

Re: RA8875 with image help

Post by adafruit_support_mike »

The major limit in writing images to a display is usually the speed of the SPI bus.

Trying to do wavelet math would also put a heavy load on the microcontroller though, so it's hard to say what dominates the delay you're seeing.

What microcontroller are you using, and what's your SPI bus speed? Also, have you tried loading a BMP file for comparison?

User avatar
keaster20
 
Posts: 4
Joined: Sun May 22, 2022 8:17 am

Re: RA8875 with image help

Post by keaster20 »

I'm using an ESP8266. Not sure what spi speed is being used. Nothing to do with spi has been changed so let's assume default speed.

User avatar
adafruit_support_mike
 
Posts: 67454
Joined: Thu Feb 11, 2010 2:51 pm

Re: RA8875 with image help

Post by adafruit_support_mike »

The ESP8266 has an 80MHz CPU clock, and SPI is typically half of that (1 cycle to write, 1 cycle to read), so getting data to the display probably isn't the major limit.

The RA8875 library is a subclass of GFX, our graphics primitives library, unlike some of our newer display libraries that are subclasses of SPITFT (which is integrated with GFX). That shouldn't have any effect on the ImageReader library, which mostly talks to the SD card.

The GFX library definitely works with BMP images, so you should be okay.

User avatar
keaster20
 
Posts: 4
Joined: Sun May 22, 2022 8:17 am

Re: RA8875 with image help

Post by keaster20 »

I was able to get this to work testing a ili9341 display but after changing all the requirements in the setup for the RA8875 library when I compile the code this the error I get

cannot convert 'Adafruit_RA8875' to 'Adafruit_SPITFT&'

Locked
Please be positive and constructive with your questions and comments.

Return to “Arduino”