Liudr,
Thank you for the firmware.
I will be ordering at least one rotary encoder keypad kit from your InMojo store.
I have built several Arduino projects that require a menu system user interface. I used MENWIZ for the last one. Your Phi hardware products and Phi libraries offer (IMHO) very elegant solutions and many options. The serial LCD backpack and rotary encoder keypad fits my next project perfectly. I like the fact that it frees up so many pins on my main Arduino and doesn't burden it with LCD and encoder I/O. Using Basic ASCII control characters and ANSI escape sequences will make it easy to communicate with the display. Reminds me of my days making user menus on VT 100's.
Keep up the good work!
Igor27