STM32 (BluePill) GRBL offline Controller test

Testing GRBL Offline controller with STM32 (Bluepill) board
This is an offline controller for a CNC machine with GRBL V1.1 on STM32F103C8T6 blue pill.
It executes the basic functions, such as:
-Displaying the status of the machine
-Move the axes
-Auto Home ($H)
-Unlock grbl ($X)
-Make position 0 (G92 on all axes)
-Read a MicroSD and send the commands to the machine
-Modify in real time the speed of movement of the machine
-Modify in real time the spindle RPM
Components:
-STM32 BluePill
-Rotary encoder
-SPI microSD card reader
-LCD screen with i2c module
You can download source code (bin file) and schematic from here:
github.com/cnc...
this controller is based on Arduino Mega offline controller:
github.com/cgu...