The whole summer has passed and I've finally finished the next version of the toy according to my plan. There are several significant changes which you've probably noticed:
The second change is a new ATmega1284P MCU which replaces the previous ATmega328P one.
It is the most important improvement over the previous versions because of the 32 KiB -> 128 KiB flash memory (the only memory on the board to carry a lot of the graphic sprites, for example). An amount of RAM has also been increased from 2 KiB on ATmega328P to 16 KiB on ATmega1284P.
The third change is almost the same OLED display which color is white now instead of the yellow on the previous prototypes and connected using SPI.
All of the previous displays with SH1106 controller were connected via two-wire interface (TWI, another name for I2C) which is relatively slow comparing to the SPI.
However, a driver for the SH1106-based displays I'm working on doesn't support SPI yet. This is the next step on my way and this new Xling v0.3 will help me testing it.
Anyway, if you have any questions and ideas on your mind, feel free to tell me then.
Have a good time!