This CC:10 contest was a pretty hard contest, and also it was done during the final months of school. These two factors made it hard for people to compete in it or make a working robot for it. I was one of only four or five people making an ATM. Unfortunatley no one else was able to complete their ATM, so I have the only entry.

This is RTM, my ATM machine.

The money dispensers work like this: The three types of bills (tens, fives, and ones) are placed in three different bins, stacked vertically above a container. A motorized wheel is positioned above the stack of bills in each container. To dispense money, the wheel - which is built so that it can exert pressure on the top bill no matter how high or low the stack is - rotates, pushing the top bill through a complex route, thereby seperating it from the rest of the bills. It pushes the bill out of the container, down a chute, and into the container below, where the user can take the money. The same method is used for all three money bins.

I made the card reader so that, when a user inserts a card, a motor brings it in at an even rate over a light sensor. Each of the three cards starts out with a black block and then a white block. With this knowledge, the card reader measures how much time it needs to wait before checking the color code again. This eliminates the problem of the battery level making the card go in too fast or too slow. The light sensor reads the card by scanning the color code, and detects which account it is if the card is a correct one. If it's a false card, RTM beeps, ejects the card, and makes the user start over. If correct, RTM ejects the card and the user can enter the PIN.

The keypad is composed of three buttons: a "switch", "select", and "enter" button. The display (on an RCX) shows a 0 at first. When the user presses the "select" button, the display changes to 1, then 2, 3, and so on, up to 9. Then it resets back to 0. When the user gets to the desired digit, he presses the "select" button, which selects that digit, moves it to the left, and lets him select another digit. For the PIN, after 5 digits have been selected, RTM reads the number, and if it matches with the card's account it gives the user access to the money withdrawal.

The money withdrawal feature works much the same way as the PIN, except that when a desired amount of money is entered, the user presses "Enter" to enter that amount. If that amount isn't over the amount of money in the users account, RTM breaks down the number into 10's, 5's, and 1's, in the least number of bills (so it will dispense the most tens, then fives, and the rest out of ones) and then dispenses them into a small container.

To reload money into RTM, a door in back can be opened, revealing three slots that go into the money bins. Bills can be slid through these slots into the bins, from which they are dispensed.

Interesting Notes:

 -The accounts PINs and amounts of money:
  #1: 35182 - $100.00
  #2: 27435 - $110.00
  #3: 57293 - $30.00

 -Parts used: 2 RCX's, 4 motors, 2 sensors, hundreds of legos.

 -Used NQC as programming language