document

examples/keybrd_shift_register/keybrd_shift_register.ino

@@ -1,8 +1,11 @@
 /* keybrd_shift_reg.ino
 tested on Teensy LC and daisy chained 74HC165 shift registers
-add this line to RowScanner_SPIShiftRegisters::scan():
+
-    //clear unpowered pins (for testing bb)
+the keyboard hardware for this sketch has 4 shift registers,
-    rowState &= 0b01010001000100010001000100010001; //also 31st key
+ with every 4th input pins connected to a pull-down resistor and matrix column.
+unused input pins are not grounded, so add this line to RowScanner_SPIShiftRegisters::scan():
+    //clear unpowered pins (for testing on breadboard)
+    rowState &= 0b01010001000100010001000100010001;
 
 Layout
 | Left  |**0**|**1**| | Right |**0**|**1**|**2**|**3**|**4**|**5**|**6**|**7**|**8**|
@@ -23,14 +26,10 @@ Layout
 #include <Row_ShiftRegisters.h>
 
 // =============== CONFIGURATION ===============
-const unsigned int RowBase::DELAY_MICROSECONDS = 500; //500
+const unsigned int RowBase::DELAY_MICROSECONDS = 0; //500
+const bool RowScanner_PinsArray::ACTIVE_HIGH = 0; //left matrix is active low
 const uint8_t RowScanner_SPIShiftRegisters::SHIFT_LOAD = 10;
 
-//activeLow  has diode cathode (band) on row
-//activeHigh has diode cathode (band) on col, and pull down resistors on cols
-//0=active low, 1= active high
-const bool RowScanner_PinsArray::ACTIVE_HIGH = 0;
-
 Debug debug;
 
 // ================= LEFT PINS =================
@@ -71,6 +70,7 @@ Row_uC row_L1(1, readPins, READ_PIN_COUNT, ptrsKeys_L1);
 //Row_ShiftRegisters(STROBE_PIN, ptrsKeys[], KEY_COUNT)
 //the s_z are place holders and should not print
 
+/*
 //prints 0 1
 Key* ptrsKeys_R0[] = { &s_0, &s_z, &s_z, &s_z, &s_1, &s_z, &s_z, &s_z };
 const uint8_t KEY_R0_COUNT = sizeof(ptrsKeys_R0)/sizeof(*ptrsKeys_R0);
@@ -80,6 +80,7 @@ Row_ShiftRegisters row_R0(8, ptrsKeys_R0, KEY_R0_COUNT);
 Key* ptrsKeys_R1[] = { &s_a, &s_z, &s_z, &s_z, &s_b, &s_z, &s_z, &s_z };
 const uint8_t KEY_R1_COUNT = sizeof(ptrsKeys_R1)/sizeof(*ptrsKeys_R1);
 Row_ShiftRegisters row_R1(9, ptrsKeys_R1, KEY_R1_COUNT);
+*/
 /*
 //prints 0 1 2
 Key* ptrsKeys_R0[] = { &s_0, &s_z, &s_z, &s_z, &s_1, &s_z, &s_z, &s_z,
@@ -103,8 +104,7 @@ const uint8_t KEY_R0_COUNT = sizeof(ptrsKeys_R0)/sizeof(*ptrsKeys_R0);
 Row_ShiftRegisters row_R0(8, ptrsKeys_R0, KEY_R0_COUNT);
 */
 
-/*
+//prints 0 1 2 3 4 5 6 7 8, microseconds_per_scan=87
-//prints 0 1 2 3 4 5 6 7 8
 Key* ptrsKeys_R0[] = { &s_0, &s_z, &s_z, &s_z, &s_1, &s_z, &s_z, &s_z,
                        &s_2, &s_z, &s_z, &s_z, &s_3, &s_z, &s_z, &s_z,
                        &s_4, &s_z, &s_z, &s_z, &s_5, &s_z, &s_z, &s_z,
@@ -119,14 +119,13 @@ Key* ptrsKeys_R1[] = { &s_a, &s_z, &s_z, &s_z, &s_b, &s_z, &s_z, &s_z,
                        &s_g, &s_z, &s_z, &s_z, &s_h, &s_z, &s_i }; //31-key limit because endRow
 const uint8_t KEY_R1_COUNT = sizeof(ptrsKeys_R1)/sizeof(*ptrsKeys_R1);
 Row_ShiftRegisters row_R1(9, ptrsKeys_R1, KEY_R1_COUNT);
-*/
 
 const uint8_t LED_PIN = 16;                     //indicates wait
 
 //sometimes OS takes 6 seconds to recongnize keyboard, LED blinks from the begining
 void wait()
 {
-    for (uint8_t count = 0; count < 7; count++)
+    for (uint8_t count = 0; count < 6; count++)
     {
         //print count
         Keyboard.print(count);
@@ -164,5 +163,5 @@ void loop()
 
 //delay(100);
 //Keyboard.println("");
-//debug.print_microseconds_per_scan();
+debug.print_microseconds_per_scan();
 }

src/RowScanner_SPIShiftRegisters.h

@@ -7,33 +7,27 @@
 #include <RowPort.h>
 #include <ColPort.h>
 
-/* RowScanner_SPIShiftRegisters reads all shift registers in a daisy chain.
+/* RowScanner_SPIShiftRegisters reads shift registers.
+shift registers 74HC165 Parallel-In-Serial-Out (PISO)
+
+in sketch:
+    const uint8_t RowScanner_SPIShiftRegisters::SHIFT_LOAD = 10;
+    call begin() from setup()
+
+Upto 4 shift registers can be in a daisy chained.
 The maximum keys per row is 31, because Arduino's largest type is 32 bits and rowEnd consumes the last bit.
-//todo delete: Assumes only one row of shift registers is connected (no Slave Select).
 
-For active low:
+The shift registers are active high:
-    10k pull-up resistor are connected to power
-    connect controller's MISO pin to shift register's /QH pin
-    in sketch, const bool RowScanner_PinsArray::ACTIVE_HIGH = 0;
-
-For active high:
     10k pull-down resistors are grounded
     connect controller's MISO pin to shift register's QH pin
-    in sketch, const bool RowScanner_PinsArray::ACTIVE_HIGH = 1;
-
-shift registers 74HC165 Parallel-In-Serial-Out (PISO) are Daisy chained
-
-The maximum keys per row is 31, because Arduino's largest type is 32 bits and rowEnd consumes the last bit.
-call begin() from setup()
 
 */
 class RowScanner_SPIShiftRegisters : public RowScannerInterface
 {
     private:
-        //todo static const bool ACTIVE_HIGH;          //logic level of strobe pin: 0=activeLow, 1=activeHigh
+        static const uint8_t SHIFT_LOAD;        //controller's pin number that is connected to shift register's SHIFT_LOAD pin
-        static const uint8_t SHIFT_LOAD;               //controller's pin number that is connected to shift register's SHIFT_LOAD pin
         const uint8_t STROBE_PIN;               //Arduino pin number connected to this row
-        const read_pins_mask_t ROW_END;                //number of keys in row  + 1
+        const read_pins_mask_t ROW_END;         //bitwise, 1 bit marks positioned after last key of row
         const uint8_t BYTE_COUNT;               //number of bytes to read from shift registers
     public:
         RowScanner_SPIShiftRegisters(const uint8_t STROBE_PIN, uint8_t KEY_COUNT);