Matrix of toggle switches and tactile buttons

hi,
i working on project in need read state 80 momentary , toggle switches.
i decided organize them in matrix.
so designed pcb there 80 molex 1x2 molex connectors in 8 cols , 10 rows connect switches. each has diode , connected, prevent masking , ghosting.
and contain 10x1 , 8x1 connector connect rows , cols arduino.
for created prototype on perfboard 2*8 matrix.
i need check switch states every loop , if state of switch has changed need send message pc on serial. wrote code uses internal pullup resistors of arduino.
it works well, message twice, me means switches bouncing...
the problem have no idea how correctly debounce matrix.
and have no idea if idea put momentary , toggle switches in same matrix.
i think debounce should done checking switch states out bit later , if state still same, not because of bouncing, cannot use delay() because other inputs , outputs should not blocked. (i need add several leds , servos later project...)

my code is:

code: [select]

//initialise matrix switches , push buttons
const byte switch_panel_rows = 2;
const byte switch_panel_cols = 8;

byte switch_panel_row_pins[switch_panel_rows] = {2, 3};
byte switch_panel_col_pins[switch_panel_cols] = {14,15,16,17,18,19,20,21};

//create array store states of switches
bool switchpanellaststate[switch_panel_rows][switch_panel_cols];

//settings serial
const int baud_rate = 9600;
const int serial_timeout = 50;

//is pc connected?
bool iscomputerconnected = false;

//declare functions
void scanswitchpanel(bool initialscan = false);
//end of declare

void setup()
{
  //first set row pins
  for(byte i=0; < switch_panel_rows; i++)
  {
    pinmode(switch_panel_row_pins[i], input_pullup);
  }

  scanswitchpanel(true);
 
  //start serial testing
  serial.begin(baud_rate);
  serial.settimeout(serial_timeout);
}

void loop() {
  //read message pc if available
  if(serial.available())
  {
    char commandbuffer = serial.read();
    int valuebuffer = serial.parseint();
//if c1 means simconnect client app
//on pc wants connect arduino
//c0 means, softaware on pc has quited
    if(commandbuffer == 'c')
    {
if(valuebuffer == 1)
{
iscomputerconnected = true;
serial.print('c');
serial.print(1);
serial.print('\n');
//then need send initial states of switches
for (byte r = 0; r < switch_panel_rows; r++)
{
for (byte c = 0; c < switch_panel_cols; c++)
{
serial.print('s');
serial.print(r);
serial.print(',');
serial.print(c);
serial.print(',');
serial.print(switchpanellaststate[r][c] ? 1 : 0);
serial.print(';');
}
}
//then indicate finished transmission
serial.print('i');
serial.print(';');
}
else if (valuebuffer == 0)
{
iscomputerconnected = false;
}
    }
  }
  scanswitchpanel();
}

void scanswitchpanel(bool initialscan )
{
for (byte c = 0; c < switch_panel_cols; c++)
{
//we set column value low
pinmode(switch_panel_col_pins[c], output);
digitalwrite(switch_panel_col_pins[c], low);

//read row values
for (byte r = 0; r < switch_panel_rows; r++)
{
if (initialscan)
{
//if first scan of switches save values
switchpanellaststate[r][c] = //we need negate becuase read
!((bool)digitalread(switch_panel_row_pins[r])); //high if switch off , low when on :)
}
else
{
//otherwise save if has changed
if (switchpanellaststate[r][c] != !((bool)digitalread(switch_panel_row_pins[r])))
{
//we save value
switchpanellaststate[r][c] = !((bool)digitalread(switch_panel_row_pins[r]));
//and send serial message if pc connected
if (iscomputerconnected)
{
serial.print('s');
serial.print(r);
serial.print(',');
serial.print(c);
serial.print(';');
//serial.flush();
}
}
}
}

//set high
digitalwrite(switch_panel_col_pins[c], high);
pinmode(switch_panel_col_pins[c], input);

}

}

and enclosing schematics of board.


what suggestions debouncing matrix?

thanks in advance help!

hi,
try library called keypad.

http://playground.arduino.cc/code/keypad

it uses matrix arrangement have.

tom...

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