fixed usart callbacks not working

software/firmware/project_oracle_test_firmware/d21/oracle_test_d21/oracle_test_d21/src/drivers/p_usart.c

@@ -50,6 +50,7 @@ void p_printf(const char* str, ...)
 		return;
 	}
 	usart_write_buffer_wait(&p_debug_inst, pprint_buffer, strsize);
+	usart_read_job(&p_debug_inst, &rx_char);
 }
 
 void p_debug_start_service(void)

software/firmware/project_oracle_test_firmware/d21/oracle_test_d21/oracle_test_d21/src/oracle.c

@@ -32,6 +32,7 @@ void oracle_init(void)
 	disp_drv.buffer = &disp_buf;          /*Assign the buffer to the display*/
 	lv_disp_drv_register(&disp_drv);      /*Finally register the driver*/
 	
+	p_debug_start_service();
 }
 
 void oracle_service(void)