#define DATA_PORT PORTC
#define DATA_DDR DDRC
#define DATA_PIN 7
+#define DATA_OUT PINC
#define CLOCK_PORT PORTC
#define CLOCK_DDR DDRC
volatile uint8_t KeyIndex_Add_InputSignal; // Used to pass the (click/input value) to the keyboard for the clicker
volatile uint8_t currentWaveState = 0;
+volatile uint8_t currentWaveDone = 0;
+volatile uint8_t positionCounter = 0;
// Buffer Signals
if ( currentWaveState )
{
CLOCK_PORT &= ~(1 << CLOCK_PIN);
- currentWaveState--;
+ currentWaveState--; // Keeps track of the clock value (for direct clock output)
+ currentWaveDone--; // Keeps track of whether the current falling edge has been processed
+ positionCounter++; // Counts the number of falling edges, reset is done by the controlling section (reset, or main scan)
}
else
{
// Setup Timer Pulse (16 bit)
// TODO Clock can be adjusted to whatever (read chip datasheets for limits)
- // 16 MHz / (2 * Prescaler * (1 + OCR1A)) = 1200.1 baud
+ // This seems like a good scan speed, as there don't seem to be any periodic
+ // de-synchronization events, and is fast enough for scanning keys
+ // Anything much more (100k baud), tends to cause a lot of de-synchronization
+ // 16 MHz / (2 * Prescaler * (1 + OCR1A)) = 10k baud
// Prescaler is 1
- // Twice every 1200 baud (actually 1200.1, timer isn't accurate enough)
- // This is close to 820 us, but a bit slower
cli();
TCCR1B = 0x09;
- OCR1AH = 0x01;
- OCR1AL = 0x09;
+ OCR1AH = 0x03;
+ OCR1AL = 0x1F;
TIMSK1 = (1 << OCIE1A);
CLOCK_DDR = (1 << CLOCK_PIN);
sei();
// Initially buffer doesn't need to be cleared (it's empty...)
BufferReadyToClear = 0;
- // InputSignal is off by default
- KeyIndex_Add_InputSignal = 0x00;
-
// Reset the keyboard before scanning, we might be in a wierd state
scan_resetKeyboard();
}
// Once the end of the packet has been detected (always the same length), decode the pressed keys
inline uint8_t scan_loop()
{
- return 0;
-}
-
-void processKeyValue( uint8_t keyValue )
-{
- // Interpret scan code
- switch ( keyValue )
+ // Read on each falling edge/after the falling edge of the clock
+ if ( !currentWaveDone )
{
- case 0x00: // Break code from input?
- break;
- default:
- // Make sure the key isn't already in the buffer
- for ( uint8_t c = 0; c < KeyIndex_BufferUsed + 1; c++ )
+ // Sample the current value 50 times
+ // If there is a signal for 40/50 of the values, then it is active
+ // This works as a very simple debouncing mechanism
+ // XXX Could be done more intelligently:
+ // Take into account the frequency of the clock + overhead, and space out the reads
+ // Or do something like "dual edge" statistics, where you query the stats from both rising and falling edges
+ // then make a decision (probably won't do much better against the last source of noise, but would do well for debouncing)
+ uint8_t total = 0;
+ uint8_t c = 0;
+ for ( ; c < 50; c++ )
+ if ( DATA_OUT & (1 << DATA_PIN) )
+ total++;
+
+
+ // Only use as a valid signal
+ if ( total >= 40 )
{
- // Key isn't in the buffer yet
- if ( c == KeyIndex_BufferUsed )
+ // Reset the scan counter, all the keys have been iterated over
+ // Ideally this should reset at 128, however
+ // due to noise in the cabling, this often moves around
+ // The minimum this can possibly set to is 124 as there
+ // are keys to service at 123 (0x78)
+ // Usually, unless there is lots of interference,
+ // this should limit most of the noise.
+ if ( positionCounter >= 124 )
{
- bufferAdd( keyValue );
+ positionCounter = 0;
- // Only send data if enabled
- if ( KeyIndex_Add_InputSignal )
- scan_sendData( KeyIndex_Add_InputSignal );
- break;
+ // Clear key buffer
+ KeyIndex_BufferUsed = 0;
}
+ // Key Press Detected
+ else
+ {
+ char tmp[15];
+ hexToStr( positionCounter, tmp );
+ dPrintStrsNL( "Key: ", tmp );
- // Key already in the buffer
- if ( KeyIndex_Buffer[c] == keyValue )
- break;
+ bufferAdd( positionCounter );
+ }
}
- break;
+
+ // Wait until the next falling clock edge for the next DATA scan
+ currentWaveDone++;
}
-}
-void removeKeyValue( uint8_t keyValue )
-{
- // Check for the released key, and shift the other keys lower on the buffer
- uint8_t c;
- for ( c = 0; c < KeyIndex_BufferUsed; c++ )
+ // Check if the clock de-synchronized
+ // And reset
+ if ( positionCounter > 128 )
{
- // Key to release found
- if ( KeyIndex_Buffer[c] == keyValue )
- {
- // Shift keys from c position
- for ( uint8_t k = c; k < KeyIndex_BufferUsed - 1; k++ )
- KeyIndex_Buffer[k] = KeyIndex_Buffer[k + 1];
+ char tmp[15];
+ hexToStr( positionCounter, tmp );
+ erro_dPrint( "De-synchronization detected at: ", tmp );
+ errorLED( 1 );
- // Decrement Buffer
- KeyIndex_BufferUsed--;
+ positionCounter = 0;
+ KeyIndex_BufferUsed = 0;
- break;
- }
+ // A keyboard reset requires interrupts to be enabled
+ sei();
+ scan_resetKeyboard();
+ cli();
}
- // Error case (no key to release)
- if ( c == KeyIndex_BufferUsed + 1 )
- {
- errorLED( 1 );
- char tmpStr[6];
- hexToStr( keyValue, tmpStr );
- erro_dPrint( "Could not find key to release: ", tmpStr );
- }
+ // Regardless of what happens, always return 0
+ return 0;
}
// Send data
}
// Reset/Hold keyboard
-// NOTE: Does nothing with the BETKB
+// NOTE: Does nothing with the HP150
void scan_lockKeyboard( void )
{
}
-// NOTE: Does nothing with the BETKB
+// NOTE: Does nothing with the HP150
void scan_unlockKeyboard( void )
{
}
// Reset Keyboard
void scan_resetKeyboard( void )
{
- // TODO Determine the scan period, and the interval to scan each bit
+ info_print("Attempting to synchronize the keyboard, do not press any keys...");
+ errorLED( 1 );
+
+ // Do a proper keyboard reset (flushes the ripple counters)
+ RESET_PORT |= (1 << RESET_PIN);
+ _delay_us(10);
+ RESET_PORT &= ~(1 << RESET_PIN);
+
+ // Delay main keyboard scanning, until the bit counter is synchronized
+ uint8_t synchronized = 0;
+ while ( !synchronized )
+ {
+ // Read on each falling edge/after the falling edge of the clock
+ if ( !currentWaveDone )
+ {
+ // Read the current data value
+ if ( DATA_OUT & (1 << DATA_PIN) )
+ {
+ // Check if synchronized
+ // There are 128 positions to scan for with the HP150 keyboard protocol
+ if ( positionCounter == 128 )
+ synchronized = 1;
+
+ positionCounter = 0;
+ }
+
+ // Wait until the next falling clock edge for the next DATA scan
+ currentWaveDone++;
+ }
+ }
+
+ info_print("Keyboard Synchronized!");
}
projects / kiibohd-controller.git / blobdiff