AVRTFT

Simple project to drive a TFT LCD with an AVR MCU (ATmega328P) and avr-libc.

Currently supported displays/drivers:

Currently implemented features:

Mostly complete UTF-8 set (code points U+0000 to U+00FF) of Hack font with antialiasing (4-Bit greyscale)
Some emojis (16-Bit RGB)
Write text in Hack including emojis 🙂
Draw bitmaps
Write text and bitmaps via USART
Upload BMP images via USART (16-Bit 5/6/5 RGB)
Process touch events (FT6206)
Very basic paint application
Logging via USART

The AVR is clocked with a crystal for reliable communication via USART.

RAM usage currently is 210 bytes. Program memory is fully used, mainly by font and emoji bitmaps.

Ideas:

Read pictures from SD Card
Display 4K@50Hz videos...

IMG_20231125_011054

Write something via USART

Connect to the controller with for example GTKTerm (38400 Baud).
Write some text and a bitmap, and upload a BMP image:

c 0xffff // clear display
d // display the demo
t 0 0 Just some text // write text in Hack to row 0 column 0
b 0 0 1 // write bitmap with index 1 (tiny Linus cat) to row 0 column 0
p 0 0 // prepare to "stream" a 16-Bit (5/6/5) RGB BMP image to row 0 column 0
cat Bali160x128.bmp > /dev/ttyUSB0 // upload a BMP image
a // start paint application

Enter emojis

Emojis are entered with a tabulation char + their "code", i.e. Smile!<TAB>s for a smiling emoji.

IMG_20231129_004922

Paint application

A super basic paint application created to learn about processing touch events and draw something on the screen.

The FT6206 based touch screen of the Adafruit 2.8" Color TFT LCD with Cap Touch 320x240 ILI9341 works quite well but at least for me the coordinates of touches close to the long edges of the screen are a bit off (too close to the edge) and there seems to be no calibration capability - the data sheet mentions "auto calibration".

But still it is fun and it should be possible to create an application supporting touch with reliable usability.

IMG_20240103_134738