Update image URLs

Give the display some more time to power up

Narrow down SD card init failure/simplify solution ...

- with the radio breakout on the same SPI bus, first 'send idle' command fails
  but second attempt (and remainig intialization) succeeds reliably

Small improvement of SD card init, correct CRC values (#14)

Small improvements ...

- fix comment
- give the display some extra time to power up

Update README.md

Update README.md

Continue impl. of RA8875 + refactoring (#12) ...

- Refactoring: same functions for all drivers
- Paint application basically works with RA8875
- Simple static touch calibration, line thickness relative to screen size
- Verify/test functionality with 320x240 cap touch display

Fix comments

Update README.md

Initial support for RA8875 (#11) ...

- add initial RA8875 support for a 800x480 TFT
- write BMP images to display (incomplete)
- implement touch with RA8875, refactoring row, col -> x, y
- Read touch point coordinates
- Handle full display hflip and vflip
- swap hflip and vflip since it was wrong
- update README.md

Display next image on touch event (#10) ...

- add script to convert images and write them raw to SD card
- disable some emojis to free space
- some minor changes

Implement reading multiple blocks from SD card (#9)

Add info on image conversion to README.md

Fail faster reading a BMP from SD card

Fail faster reading a BMP from SD card

Optimization ...

- reduce time to read, parse and write a 320x240 BMP from 2.85 to 2.61
  seconds, and there is probably still a lot of potential...

Read BMP images from SD card ...

- improve speed of BMP image parsing (3.4s -> 2.85s)
- some refactoring

Read BMP images from SD card ...

- some cleanup

Update README.md

Read BMP images from SD card (#8) ...

- initialization complete, SD card goes in ready state
- read single block
- write single block 
- some refactoring
- read BMP image raw from SD card starting from given address
- re-enable all glyphs and emojis
- sacrifice two emojis for flash space
- update README

Fix pixel shift of uploaded BMP image

Cosmetics ...

- add braces

Update README.md ...

- mention command to start paint application

Optimization ...

- don't swap endianess once and again, use memcpy

Optimization ...

- use union instead of bitshifts to join bytes

Just some cleanup

Just some cleanup/fix rounding

Initial implementation of touch screen (#7) ...

* Initial implementation of touch screen
* Updated NetBeans configuration
* Read number of touch points, cleanup
* Improve touch support

- avoid duplicate touch events by interrupting on falling edge only
- read touch event flags
- refactoring for better code reuse

* Some more refactoring
* Initial function to draw continuous lines

- connect points with a distance > 1 with linear interpolation during
  touch contact

* Fix conversion from 4-Bit greyscale to 16-Bit RGB

- removes reddish antialiasing that was present with some chars

* Add initial paint toy + related refactoring
* Add some tools with icons
* Add more tools + improvements

- draw rectangles
- set line thickness
- account for line thickness in dimensions

* Update README.md, re-enable all glyphs and emojis.

Simplify, simplify!