So for my intro to engineering class instead of a final we have to build a robot. My idea is to create a robot that will draw and play tic tac toe. The drawing system is based on the plot clock design. For parts I have 3 momentary push buttons, a 3 x 4 keypad (Membrane 3x4 Matrix Keypad + extras [3x4] : ID 419 : $3.95 : Adafruit Industries, Unique & fun DIY electronics and kits) for the human player to select where they want to play their turn, a handful of LEDs, a light up on/off switch, and 3 servos. I am using the arduino Uno to code this. I am hoping for some gentile nudges in the right direction of what are some ways i can use the 3 buttons to have different game modes (IE one with the robot making random moves based on a random number generator.) (sidenote in the case of the keypad and the random number generator, is it possible to code so that when a number has been used it cannot be played/selected again?) As for the extra buttons on the 3 x 4 keypad I am hoping to hook one up to a loop command so that the whole code is run again as sort of a "play again" button. the LEDs will hopefully be used so that when it is a players turn, the code will tell the LED to light up and then tell it to turn off once a move is made. Would it be possible for the code to identify if there is 3 variables in a row?