Automated switch scanning matrix for obtaining user input

Abstract

This invention is an automated switch scanning matrix for obtaining user input. The invention comprises an integrated circuit with an output register and an input register, the output register is operatively connected to one or more user switches or encoders and the switches or encoders are further operatively connected to the integrated circuit input register. A voltage is pulsed from the output register of the integrated circuit which then flows through closed contacts of the switches or encoders in the switching matrix and is then detected at the input registers of the integrated circuit. The switch position inputs are saved in a switch save register. The integrated circuit sets an interrupt bit if any of the switch positions in the matrix have changed. This, in turn, causes the microcontroller to read the switch save registers thereby saving time for the microcontroller by not having to continually read the switch inputs.

1 . A household appliance comprising: 
 a switch matrix for obtaining user input on the household appliance wherein the switch matrix comprises;    an integrated circuit with a logic hardware block, the logic hardware block having a source output register and a sense input register;    the source output register operatively connected to one or more user operative switches;    the switches further operatively connected to the logic hardware block sense input register.    
   
   
       2 . The appliance of  claim 1 , wherein the switch matrix further comprises a rotary encoder.  
   
   
       3 . The appliance of  claim 1 , wherein the switch matrix has a diode operatively connected between a switch and the sense input register.  
   
   
       4 . The appliance of  claim 1 , wherein a voltage is pulsed from the source register outputs.  
   
   
       5 . The appliance of  claim 4 , wherein the voltage is detected at the sense register inputs to determine if one or more of the switches has closed contacts.  
   
   
       6 . The appliance of  claim 4 , wherein the voltage pulsed is between 3 and 25 volts.  
   
   
       7 . The appliance of  claim 1  further comprising: 
 a pull-down circuit on at least one of the sense register inputs.    
   
   
       8 . The appliance of  claim 1 , further comprising a de-bounce circuit on at least one of the sense register inputs.  
   
   
       9 . The appliance of  claim 1 , wherein the integrated circuit is an application specific integrated circuit (ASIC).  
   
   
       10 . The appliance of  claim 1 , wherein at least one switch further comprises a common terminal and at least one throw terminal; the switch's common terminal is operatively connected to the integrated circuit's source register and at least one of the switch's throw terminals is operatively connected to the integrated circuit's sense register.  
   
   
       11 . The appliance of  claim 1 , wherein the appliance is from the group consisting of a washing appliance, a drying appliance, a refrigeration appliance, and a cooking appliance.  
   
   
       12 . An automated switch scanning matrix for obtaining user input on household appliances comprising: 
 a logic hardware block operatively connected to a switching matrix;    the switching matrix further comprising one or more switches;    the logic hardware block configured to scan switch positions of the switches, store information of switch positions, and determine if any of the switch positions have changed.    
   
   
       13 . The automated switch scanning matrix for obtaining user input on household appliances of  claim 12  wherein the logic hardware block sets an interrupt bit if any of the switch positions have changed.  
   
   
       14 . The automated switch scanning matrix for obtaining user input on household appliances of  claim 13  wherein the interrupt bit may be enabled or not enabled.  
   
   
       15 . The automated switch scanning matrix for obtaining user input on household appliances of  claim 13  wherein the interrupt bit causes a microcontroller to read the stored information of switch positions.  
   
   
       16 . The automated switch scanning matrix for obtaining user input on household appliances of  claim 12  wherein the logic hardware block is within an application specific integrated circuit (ASIC).  
   
   
       17 . The automated switch scanning matrix for obtaining user input on household appliances of  claim 12  wherein the household appliance is a washing appliance.  
   
   
       18 . The automated switch scanning matrix for obtaining user input on household appliances of  claim 12  wherein the switching matrix is operatively connected to the logic hardware block source register output and sense register input.  
   
   
       19 . The automated switch scanning matrix for obtaining user input on household appliances of  claim 18  wherein switches which are not part of the switching matrix are connected to the logic hardware block sense register input.  
   
   
       20 . A method of obtaining user input on household appliances comprising the steps of: 
 operatively connecting a household appliance to an integrated circuit;    operatively connecting a switching matrix to a source output register and a sensing input register of the integrated circuit;    pulsing signals from the integrated circuit's source output register to the switch matrix;    detecting signals coming from the switching matrix to the integrated circuit's sense input register;    determining what signals are being received at the integrated circuit's sense input register for each pulse of the integrated circuit's source output register outputs;    storing the switch position inputs in switch save registers;    determining if any of the switch's positions have changed; and    if the switch positions have changed, setting a status bit that a change has occurred.    
   
   
       21 . The method of  claim 20  further comprising the step of detecting if switches which are not part of the switch matrix, but are connected to the integrated circuit's sense input register have changed position.  
   
   
       22 . The method of  claim 20  further comprising the step of interrupting a processor when the switch positions have changed.  
   
   
       23 . The method of  claim 22  further comprising the step of reading the switch save registers with the processor.