Charactercontroller skin width accurate

I have try to build a 3d sokoban model, I use charactercontroller as for my player prefab with a blocky move(one keypressdown per move at a block distance). When my player touch the wall the actual position is adjust to a (0.99, 0 , 1.01) with a skin width at 0.01. I want the player perfectly touch the wall when a wall ahead and also stand in the center of a floor block instead of keep a 0.01 distance away from the wall. Here is the code I written down for player.

 using UnityEngine;
 using System.Collections;
 
 public class Player : MonoBehaviour {
     
     private int counter;
     private CharacterController controller;
     private string tmp;
     // Use this for initialization
     void Start () {
         this.controller = GetComponent<CharacterController>();
         this.counter = -1;
     }
     
     // Update is called once per frame
     void Update () {
         if (Input.GetKeyDown(KeyCode.UpArrow))
         {
             MoveUp();
         }
         if (Input.GetKeyDown(KeyCode.DownArrow))
         {
             MoveDown();
         }
         if (Input.GetKeyDown(KeyCode.LeftArrow))
         {
             MoveLeft();
         }
         if (Input.GetKeyDown(KeyCode.RightArrow))
         {
             MoveRight();
         }
     }
     //Control player to move up
     void MoveUp()
     {
         controller.Move(Vector3.forward);
     }
     //Control player to move down
     void MoveDown()
     {
         controller.Move(Vector3.back);
     }
     //Control player to move left
     void MoveLeft()
     {
         controller.Move(Vector3.left);
     }
     //control player to move right
     void MoveRight()
     {
          controller.Move(Vector3.right);
     }
 
 
 
    public void OnControllerColliderHit(ControllerColliderHit hit)
     {
         if(hit.gameObject.tag == "Crate")
         {
             Crate crate = hit.gameObject.GetComponent<Crate>();
             Vector3 direction;
             if (tmp == "Up")
             {
                 direction = new Vector3(0, 0, 1);
             } else if (tmp == "Down")
             {
                 direction = new Vector3(0, 0, -1);
             }else if(tmp == "Left")
             {
                 direction = new Vector3(-1, 0, 0);
             }else if(tmp == "Right")
             {
                 direction = new Vector3(1, 0, 0);
             }
             else
             {
                 direction = new Vector3(0, 0, 0);
             }
             Debug.Log(direction);
             Debug.Log(tmp);
             crate.Push(direction);
         }
     }
 
 }
 
 using UnityEngine;
 using System.Collections;
 
 public class Wall : MonoBehaviour {
 
     // Use this for initialization
     void Start () {
     }
     
     // Update is called once per frame
     void Update () {
     
     }
 }
 
 using UnityEngine;
 using System.Collections;
 
 public class Crate : MonoBehaviour {
     private Vector3 targetPosition;
     private bool moving = false;
     // Use this for initialization
     void Start () {
         this.targetPosition = this.transform.position;
     }
     
     // Update is called once per frame
     void Update () {
         if(this.transform.position == this.targetPosition)
         {
             this.moving = false;
             return;
         }
 
         if (this.moving)
         {
             float step = 3.5f * Time.deltaTime;
             this.transform.position = Vector3.MoveTowards(this.transform.position, this.targetPosition, step);
         }
     }
 
     public void Push(Vector3 direction)
     {
         if (this.moving)
             return;
         if (Physics.Raycast(this.transform.position, direction, 0.4f))
         {
             this.moving = false;
             return;
         }
 
         this.moving = true;
         this.targetPosition = transform.position + direction;
         Debug.Log(targetPosition);
     }
 }