This is a handy Java GUI utility to convert a BMP file into the array code necessary to display the image with the drawBitmap function. Check out the code at ehubin’s GitHub repository: https://github.com/ehubin/Adafruit-GFX-Library/tree/master/Img2Code Note that this is a java-based program and you might need to install java from http://www.java.com/en/download/ if you haven’t already done so. Another tool, did not try. One more http://en.radzio.dxp.pl/bitmap_converter/ for windows?

1. Download the utility from above link

2. Run the java utility

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   java -jar Image2Code.jar

3. Click choose file to convert, copy the code, and paste it into Arduino sketch.

   

NB: DrawBitmap in Arduino Sketch

1. Add following (otherwise it will display garbage) in front of the array:

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   static const uint8_t  PROGMEM myBitmap[] = {0xff...

   and draw with following code:

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   tft.drawBitmap(220, 160, myBitmap, 82, 77, BLACK); //make sure the width and height is exactly the dimension of the image, drawXBitmap does NOT work

2. screenshots with Adafruit and Arch Linux logos

   

You can use the GIMP photo editor to save a .xbm file and use the array saved in the file to draw a bitmap with the drawXBitmap function. See the pull request here for more details: https://github.com/adafruit/Adafruit-GFX-Library/pull/31

Usage:

1. Export from GIMP to *.xbm, rename *.xbm to *.c and open in editor.
2. C Array can be directly used with this function

3. Arduino Sketch

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   static const uint8_t  PROGMEM myBitmap[] = {0xff...

   and draw with following code:

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   tft.drawXBitmap(220, 160, myBitmap, 82, 77, BLACK); //drawXBitmap