add RowBase::wait()

src/Row.cpp

@@ -30,31 +30,6 @@ need a larger SAMPLE_COUNT for reliability.
 Larger SAMPLE_COUNTs are more reliable but consume more memory, where
      SAMPLE_COUNT*ROW_COUNT = bytes of memory consumed by keyboard
 SAMPLE_COUNT = 4 is very reliable for a keyboard.
-
-Avoid sampling the switch input at a rate synchronous to events in the environment
- that might create periodic EMI. For instance, 50 and 60 Hz.
-
-A keyboard with a faster scan rate responds faster.
-Follow these step to tune DELAY_MICROSECONDS for maximum scan rate for a given SAMPLE_COUNT:
-Initialize DELAY_MICROSECONDS in your sketch:
-    const unsigned int Row::DELAY_MICROSECONDS = 1000;
-Add this to the sketch's loop() function:
-    debug.print_microseconds_per_scan();
-Compile and load the sketch into the microcontroller; microseconds_per_scan is printed every second.
-Adjust the value of DELAY_MICROSECONDS and repeat until:
-    debug.print_microseconds_per_scan() <= DEBOUNCE_TIME / SAMPLE_COUNT
-
-DEBOUNCE_TIME can be obtained from the switch's datasheet.  Some switch bounce times are:
-Cherry MX specifies 5msec bounce time http://www.cherrycorp.com/english/switches/key/mx.htm
-hasu measured Cherry MX bounce times .3ms to 1.4ms http://geekhack.org/index.php?topic=42385.0
-Tactile switch MJTP series bounce 10 ms http://www.apem.com/files/apem/brochures/MJTP_6MM.pdf 
-
-Polling I2C may slow the scan rate enough so that no additional delay is needed:
-    const unsigned int Row::DELAY_MICROSECONDS = 0;
-
-Slow-scan trick for debug messages that print too fast:
-    change DELAY_MICROSECONDS to a large number like 10000
-That way debug messages are printed at a managable rate.
 */
 /* debounce() function
 Parameter rowState is bitwise, 1 means pressed, 0 means released.

src/Row.h

@@ -33,7 +33,6 @@ Number of ColPort::colPins should equal number of keys in Row::ptrsKeys array
 class Row : public RowBase
 {
     private:
-        static const unsigned int DELAY_MICROSECONDS; //delay between each Row scan for debouncing
         uint8_t samples[SAMPLE_COUNT];          //bitwise, one bit per key, most recent readings
         uint8_t samplesIndex;                   //samples[] current write index
         virtual uint8_t debounce(const uint8_t rowState);

src/RowBase.cpp

@@ -9,12 +9,44 @@ void RowBase::process(const bool activeHigh)
     uint16_t rowEnd;                            //1 bit marks positioned after last key of row
     uint8_t debouncedChanged;                   //1 means debounced changed
 
+    wait();
     scan(activeHigh);                           //save column-port-pin values to portState
     rowState = getRowState(rowEnd, activeHigh);
     debouncedChanged = debounce(rowState);
     pressRelease(rowEnd, debouncedChanged);
 }
 
+/* wait() delay's scan to give switches time to debounce.
+This version of wait() is very simple.  More sophisticated versions can override this one.
+
+For fastest response time, wait() should be placed before scan() or after pressRelease()
+ (waiting between strobe and send would unnecessarily delay send).
+
+A keyboard with a faster scan rate responds faster.
+Follow these step to tune DELAY_MICROSECONDS for maximum scan rate for a given SAMPLE_COUNT:
+Initialize DELAY_MICROSECONDS in your sketch:
+    const unsigned int Row::DELAY_MICROSECONDS = 1000;
+Add this to the sketch's loop() function:
+    debug.print_microseconds_per_scan();
+Compile and load the sketch into the microcontroller; microseconds_per_scan is printed every second.
+Adjust the value of DELAY_MICROSECONDS and repeat until:
+    debug.print_microseconds_per_scan() <= DEBOUNCE_TIME / SAMPLE_COUNT
+
+DEBOUNCE_TIME can be obtained from the switch's datasheet.  Some switch bounce times are:
+Cherry MX specifies 5msec bounce time http://www.cherrycorp.com/english/switches/key/mx.htm
+hasu measured Cherry MX bounce times .3ms to 1.4ms http://geekhack.org/index.php?topic=42385.0
+Tactile switch MJTP series bounce 10 ms http://www.apem.com/files/apem/brochures/MJTP_6MM.pdf 
+
+Avoid sampling the switch input at a rate synchronous to events in the environment
+ that might create periodic EMI. For instance, 50 and 60 Hz.
+
+Polling I2C may slow the scan rate enough so that no additional delay is needed:
+    const unsigned int Row::DELAY_MICROSECONDS = 0;
+
+Slow-scan trick for debug messages that print too fast:
+    change DELAY_MICROSECONDS to a large number like 10000
+That way debug messages are printed at a managable rate.
+*/
 void RowBase::wait()
 {
     delayMicroseconds(DELAY_MICROSECONDS);      //delay between Row scans to debounce switches

src/RowBase.h

@@ -11,6 +11,7 @@
 class RowBase
 {
     private:
+        static const unsigned int DELAY_MICROSECONDS; //delay between each Row scan for debouncing
         Key *const *const ptrsKeys;         //array of Key pointers
 
         RowPort &refRowPort;                //this row's IC port
@@ -19,6 +20,7 @@ class RowBase
         ColPort *const *const ptrsColPorts; //array of column ports
         const uint8_t colPortCount;
 
+        void wait();
         void scan(const bool activeHigh);
         uint8_t getRowState(uint16_t& rowEnd, const bool activeHigh);
         virtual uint8_t debounce(const uint8_t rowState)=0;