diff --git a/pedro/snake/snake.ino b/pedro/snake/snake.ino
new file mode 100644
index 0000000..4e98e7d
--- /dev/null
+++ b/pedro/snake/snake.ino
@@ -0,0 +1,153 @@
+#define BOARD_LENGTH 8
+
+struct pair {
+  int x;
+  int y;
+};
+
+class Snake {
+private:
+  char state;
+  int snake_size;
+  pair pos[64];
+  pair get_next_move(pair p);
+
+public:
+  Snake() {
+    this->state = 'U';
+    this->snake_size = 4;
+    for (int i = snake_size - 1; i >= 0; i--) {
+      pair p;
+      p.x = 5;
+      p.y = i;
+      this->pos[i] = p;
+    }
+  }
+  void change_state(char m);
+  void eat(pair p);
+  void snake_to_matrix(int (*pixels)[BOARD_LENGTH]){
+    for(int i = 0; i < BOARD_LENGTH; i++){
+      for(int j = 0; j < BOARD_LENGTH; j++){
+        pixels[i][j] = HIGH; // CLEAR ALL PIXELS;
+      }
+    }
+    for(int i = 0; i < snake_size; i++) {
+      pair p = pos[i];
+      pixels[p.x][p.y] = LOW; // TURN ON PIXELS OF SNAKE
+    }
+  }
+  void next_move();
+  pair snake_head() {
+    return pos[0];
+  }
+};
+
+pair Snake::get_next_move(pair p) {
+  pair r;
+  switch (state) {
+  case 'U':
+    r.x = (p.x + BOARD_LENGTH - 1) % BOARD_LENGTH;
+    r.y = p.y;
+    break;
+  case 'D':
+    r.x = (p.x + 1) % BOARD_LENGTH;
+    r.y = p.y;
+    break;
+  case 'L':
+    r.x = p.x;
+    r.y = (p.y + 1) % BOARD_LENGTH;
+    break;
+  case 'R':
+    r.x = p.x;
+    r.y = (p.y + BOARD_LENGTH - 1) % BOARD_LENGTH;
+    break;
+  }
+  return r;
+}
+
+void Snake::next_move() {
+  for (int i = snake_size; i > 0; i--) {
+    pos[i] = pos[i - 1];
+  }
+  pos[0] = get_next_move(pos[0]);
+}
+
+void Snake::eat(pair p) { pos[snake_size++] = p; }
+
+const int row[8] = {2, 7, 19, 5, 13, 18, 12, 16};
+
+// 2-dimensional array of column pin numbers:
+const int col[8] = {6, 11, 10, 3, 17, 4, 8, 9};
+
+// 2-dimensional array of pixels:
+int pixels[8][8];
+
+// cursor position:
+int x = 5;
+int y = 5;
+Snake snake;
+
+void setup() {
+  // initialize the I/O pins as outputs
+  // iterate over the pins:
+  for (int thisPin = 0; thisPin < 8; thisPin++) {
+    // initialize the output pins:
+    pinMode(col[thisPin], OUTPUT);
+    pinMode(row[thisPin], OUTPUT);
+    // take the col pins (i.e. the cathodes) high to ensure that
+    // the LEDS are off:
+    digitalWrite(col[thisPin], HIGH);
+  }
+
+  // initialize the pixel matrix:
+  for (int x = 0; x < 8; x++) {
+    for (int y = 0; y < 8; y++) {
+      pixels[x][y] = HIGH;
+    }
+  }
+}
+
+void loop() {
+  // read input:
+  // readSensors();
+  snake.snake_to_matrix(pixels);
+  snake.next_move();
+  // draw the screen:
+  for(int i = 0; i < 100; i++)
+    Display();
+}
+
+void readSensors() {
+  // turn off the last position:
+  pixels[x][y] = HIGH;
+  // read the sensors for X and Y values:
+  x = 7 - map(analogRead(A0), 0, 1022, 0, 7);
+  y = map(analogRead(A1), 0, 1022, 0, 7);
+  // set the new pixel position low so that the LED will turn on
+  // in the next screen refresh:
+  pixels[x][y] = LOW;
+}
+
+void Display()    
+{  
+  for(int c = 0; c<8;c++)  
+  {  
+    digitalWrite(col[c],LOW);//use thr column 
+    //loop
+    for(int r = 0;r<8;r++)  
+    {  
+      digitalWrite(row[r],(pixels[r][c]+1)%2);  
+    }  
+    delay(1);  
+    Clear();  //Remove empty display light
+  }  
+}  
+  
+void Clear()                          //清空显示  
+{  
+  for(int i = 0;i<8;i++)  
+  {  
+    digitalWrite(row[i],LOW);  
+    digitalWrite(col[i],HIGH);  
+  }  
+}