Computer interface with hardwire button array

Abstract

The invention is a computer interface with a hardwired button array on the computer chassis for simulating the apparatus of common consumer electronic devices. Each button of the array of buttons is connected to at least two wires, with the depression of a button causing an electrical connection between the corresponding two wires. The voltage on one of these wires is forced to a steady-state logic low, while the voltage on the other wire is allowed to float electrically free. Nonetheless, the second wire is at a steady-state high voltage due to that wire's connection through a pull-up resistor to a voltage source. Upon electrical connection, the wire that is floating free acquires a logic low voltage. In response, a line state detector sends an interrupt signal to a microprocessor, which transitions the voltage on the wires forced to a steady-state logic low from a logic low to a free floating state. If the transitioned wire is connected to the depressed switch, the voltage on it rises since it is now connected through a pull-up resistor to a voltage source. Thus, the system can detect which button has been depressed since the system discerns both of the wires connected to the depressed button.