Uploaded February 2020 | Updated September 2026, 1 week ago

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Parts:
- ST7789 IPS display
- Arduino Pro Mini
- DS1307 or DS3231 RTC module
- a button

AVR version of STM32 project: youtu.be/35Z0enhEYqM

Features:
- watch dial bitmap is reduced to 2 bits per pixel (4 colors) to fit in Arduino Pro Mini flash memory
- the bitmap in 240x240x2 bits uses only 14400 bytes, full project uses 30700 bytes
- a few alternative 2-bit dials
- watch hands are are vector based
- no floating-point arithmetic and slow trigonometric functions were used

Source code and connections:
github.com/cbm80amiga/ST7789_Watch_2bit

More ST7735 and ST7789 videos:
youtube.com/watch?v=o3AqITHf0mo&list=PLxb1losWErZ6y6GombzvtwRZ2l7brPv1s
youtube.com/watch?v=GciLKcWQZK4&list=PLxb1losWErZ7thUyB05phRR3DoiYN_kcD

If you find it useful and you want to buy me a coffee or a beer:
paypal.me/cbm80amiga