add mcu flash size detect and auto config usart

Src/main.c

@@ -51,16 +51,20 @@ OF SUCH DAMAGE.
 */
 int main(void)
 {
+    led_init();
+    mcu_detect_and_config();
+
     setbuf(stdout, NULL);
 
     systick_config();
 
     rs485_init();
 
-    led_init();
     ultrasonic_config();
     ultrasonic_pwm_out_cycles();
 
+    printf("Flash size: %d Kbytes\n", get_flash_size());
+
 #ifdef DEBUG_VERBOSE
     char hello_world[] = {"Hello World!\r\n"};