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Adding timing based debounce code 

- Uses expiry timer to decide on when to allow a state change
- Initial state transitions are unaffected
- Use MinDebounceTime define in kll to configure
- ms granularity
connect
Jacob Alexander 9 years ago
parent
f708ce720c
commit
98f796d4df
3 changed files with 54 additions and 7 deletions
Split View Show Diff Stats
  1. 7
    0
      Scan/MatrixARM/capabilities.kll
  2. 37
    4
      Scan/MatrixARM/matrix_scan.c
  3. 10
    3
      Scan/MatrixARM/matrix_scan.h

+ 7
- 0
Scan/MatrixARM/capabilities.kll View File

@@ -32,3 +32,10 @@ DebounceThrottleDiv => DebounceThrottleDiv_define;
DebounceThrottleDiv = 0; # Default
#DebounceThrottleDiv = 2; # /4 divider

# This defines the minimum amount of time after a transition until allowing another transition
# Generally switches require a minimum 5 ms debounce period
# Since a decision can usually be made quite quickly, there is little latency on each press
# However, this defines the latency at which the switch state can change
MinDebounceTime => MinDebounceTime_define;
MinDebounceTime = 5; # 5 ms


+ 37
- 4
Scan/MatrixARM/matrix_scan.c View File

@@ -82,6 +82,9 @@ uint16_t matrixMaxScans = 0;
uint16_t matrixCurScans = 0;
uint16_t matrixPrevScans = 0;

// System Timer used for delaying debounce decisions
extern volatile uint32_t systick_millis_count;



// ----- Functions -----
@@ -197,10 +200,11 @@ void Matrix_setup()
// Clear out Debounce Array
for ( uint8_t item = 0; item < Matrix_maxKeys; item++ )
{
Matrix_scanArray[ item ].prevState = KeyState_Off;
Matrix_scanArray[ item ].curState = KeyState_Off;
Matrix_scanArray[ item ].activeCount = 0;
Matrix_scanArray[ item ].inactiveCount = DebounceDivThreshold_define; // Start at 'off' steady state
Matrix_scanArray[ item ].prevState = KeyState_Off;
Matrix_scanArray[ item ].curState = KeyState_Off;
Matrix_scanArray[ item ].activeCount = 0;
Matrix_scanArray[ item ].inactiveCount = DebounceDivThreshold_define; // Start at 'off' steady state
Matrix_scanArray[ item ].prevDecisionTime = 0;
}

// Clear scan stats counters
@@ -262,6 +266,9 @@ void Matrix_scan( uint16_t scanNum )
matrixCurScans++;
}

// Read systick for event scheduling
uint8_t currentTime = (uint8_t)systick_millis_count;

// For each strobe, scan each of the sense pins
for ( uint8_t strobe = 0; strobe < Matrix_colsNum; strobe++ )
{
@@ -305,11 +312,16 @@ void Matrix_scan( uint16_t scanNum )
}

// Check for state change if it hasn't been set
// But only if enough time has passed since last state change
// Only check if the minimum number of scans has been met
// the current state is invalid
// and either active or inactive count is over the debounce threshold
if ( state->curState == KeyState_Invalid )
{
// Determine time since last decision
uint8_t lastTransition = currentTime - state->prevDecisionTime;

// Attempt state transition
switch ( state->prevState )
{
case KeyState_Press:
@@ -320,6 +332,15 @@ void Matrix_scan( uint16_t scanNum )
}
else
{
// If not enough time has passed since Hold
// Keep previous state
if ( lastTransition < MinDebounceTime_define )
{
//warn_print("FAST Release stopped");
state->curState = state->prevState;
continue;
}

state->curState = KeyState_Release;
}
break;
@@ -328,6 +349,15 @@ void Matrix_scan( uint16_t scanNum )
case KeyState_Off:
if ( state->activeCount > state->inactiveCount )
{
// If not enough time has passed since Hold
// Keep previous state
if ( lastTransition < MinDebounceTime_define )
{
//warn_print("FAST Press stopped");
state->curState = state->prevState;
continue;
}

state->curState = KeyState_Press;
}
else
@@ -342,6 +372,9 @@ void Matrix_scan( uint16_t scanNum )
break;
}

// Update decision time
state->prevDecisionTime = currentTime;

// Send keystate to macro module
Macro_keyState( key, state->curState );


+ 10
- 3
Scan/MatrixARM/matrix_scan.h View File

@@ -40,6 +40,12 @@
#error "Debounce threshold is too high... 32 bit max. Check .kll defines."
#endif

#if ( MinDebounceTime_define > 0xFF )
#error "MinDebounceTime is a maximum of 255 ms"
#elif ( MinDebounceTime_define < 0x00 )
#error "MinDebounceTime is a minimum 0 ms"
#endif



// ----- Enums -----
@@ -126,11 +132,12 @@ typedef struct GPIO_Pin {

// Debounce Element
typedef struct KeyState {
KeyPosition prevState;
KeyPosition curState;
DebounceCounter activeCount;
DebounceCounter inactiveCount;
} KeyState;
KeyPosition prevState;
KeyPosition curState;
uint8_t prevDecisionTime;
} __attribute__((packed)) KeyState;