In this chapter you will
- Learn how to connect numeric keypads to your Arduino
- Read values from the keypad in a sketch
- Expand on decision systems with the
- Create a PIN-controlled lock or switch
Using a Numeric Keypad
As your projects become more involved, you might want to accept numeric input from users when your Arduino isn’t connected to a device with a keyboard. For example, you might like the ability to turn something on or off by entering a secret number. One option would be to wire up 10 or more push buttons to various digital input pins (for the numbers 0 through 9), but it’s much easier to use a numeric keypad like the one shown in Figure 11-1.
One of the ...