I have a project where in I have to count number of rotations the wheel makes. So i have put up an IR sensor and using Arduino UNo i am counting the rotations made by the wheel. Now after I shut down the board I want to start counting from where i have left from the previous count. Please help me with this.What should be the code for this? I am new to Arduino so I dont know many libraries and the access to it. Please help me asap..