As far as I can tell, no schematic has been released anywhere.
This seems to be loosely based on the T-OI-PLUS which does have a released schematic.
Based on some brief research, the major changes seem to be:
Completely eliminating the analogue input circuitry
Connecting almost all the I/O pins to the keyboard, i.e. 12 I/O pins hooked up directly to the columns and rows, and pin 9 hooked to some circuitry to drive the keyboard's backlight
Connecting the remaining I/O pins to the T-0.99-TFT module which also contains the expansion connector
The ESP32-C3 has a grand total of 22 available I/O pins including 4-7 for the program flash and 2 for the serial port, leaving a grand total of 13-16 usable pins. We have assignments for 17.
This means that there are simply no I/O pins left to dedicate to the keyboard's microphone or the battery management. Which means that the only way those could be connected to the microcontroller would be if they're doing something seriously tricky to hook these functions up to one of the ADC pins: 0-5.
As far as I can tell, no schematic has been released anywhere.
This seems to be loosely based on the T-OI-PLUS which does have a released schematic.
Based on some brief research, the major changes seem to be:
The ESP32-C3 has a grand total of 22 available I/O pins including 4-7 for the program flash and 2 for the serial port, leaving a grand total of 13-16 usable pins. We have assignments for 17.
This means that there are simply no I/O pins left to dedicate to the keyboard's microphone or the battery management. Which means that the only way those could be connected to the microcontroller would be if they're doing something seriously tricky to hook these functions up to one of the ADC pins: 0-5.