113 lines
3.7 KiB
C++
113 lines
3.7 KiB
C++
/* keybrd_2_single-layer.ino
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This sketch:
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is firmware for a simple 1-layer keyboard
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runs on two rows and two columns of a breadboard keyboard
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This layout table shows how keys are arranged on the keyboard:
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| Layout | **0** | **1** |
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|:------:|-------|-------|
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| **0** | 1 | 2 |
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| **1** | a | b |
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The layout's row and column numbers are in the headers.
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Each cell in the table's body represents a key.
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The following sketch is annotated with a walk-through narrative enclosed in comment blocks.
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Each comment block explains one or two lines of code after the comnent.
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keybrd objects are instantiated under the "GLOBAL" heading.
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The keyboard runs at the end of the sketch, under the "MAIN" heading.
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*/
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// ################## GLOBAL ###################
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/* ================= INCLUDES ==================
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All the includes in this sketch are to keybrd library classes.
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*/
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#include <Code_Sc.h>
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#include <Row.h>
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#include <Scanner_uC.h>
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#include <ScanDelay.h>
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/* ============ SPEED CONFIGURATION ============
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Keyboard switches are made of moving contacts.
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When the contacts close, they bounce apart one or more times before making steady contact.
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ScanDelay gives the switches time to debounce.
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ScanDelay specifies microsecond between matrix scans.
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*/
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ScanDelay scanDelay(9000);
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/* ================== SCANNER ==================
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Microcontroller pins 14 and 15 are connected to the matrix columns.
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sizeof() is used to compute the number of array elements.
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This eliminates the risk of a programmer forgetting to update a count
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after adding or removing an element from the array.
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*/
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uint8_t readPins[] = {14, 15};
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uint8_t readPinCount = sizeof(readPins)/sizeof(*readPins);
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/*
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Scanner_uC constructor parameters are: activeState, readPins[], readPinCount.
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activeState defines the logic level for strobes, HIGH or LOW.
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"Active low" means that if a switch is pressed (active), the read pin is low.
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The scanner uses readPins and readPinCount to read the colums.
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*/
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Scanner_uC scanner(LOW, readPins, readPinCount);
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/* HOW SCANNER OBJECTS WORK
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The Scanner object strobes a row.
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If a key is pressed, the LOW strobe pulls that readPin LOW.
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Then the scanner reads its readPins.
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*/
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/* =================== CODES ===================
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Four Codes are instantiated, one for each key in the layout.
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The Code object names in this sketch start with a "s_" prefix.
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The Code_Sc constructor takes one scancode ("Sc" means "scancode").
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When Code_Sc is pressed, it sends the scancode.
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*/
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Code_Sc s_a(KEY_A);
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Code_Sc s_b(KEY_B);
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Code_Sc s_1(KEY_1);
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Code_Sc s_2(KEY_2);
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/* =================== ROWS ====================
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Here we pack Code objects into Row objects.
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The Row objects names in this sketch start with a "row_" followed by a row number.
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Row constructor parameters are: scanner, strobePin, ptrsKeys[], keyCount.
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strobePin is the Arduino pin number connected to the row.
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ptrsKeys[] contains all the Code objects of the row, one Code object per key.
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*/
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Key* ptrsKeys_0[] = { &s_1, &s_2 };
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uint8_t keyCount_0 = sizeof(ptrsKeys_0)/sizeof(*ptrsKeys_0);
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Row row_0(scanner, 0, ptrsKeys_0, keyCount_0);
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Key* ptrsKeys_1[] = { &s_a, &s_b };
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uint8_t keyCount_1 = sizeof(ptrsKeys_1)/sizeof(*ptrsKeys_1);
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Row row_1(scanner, 1, ptrsKeys_1, keyCount_1);
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/* ################### MAIN ####################
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setup() is required by Arduino. Some keyboard firmware will initialize objects in setup().
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*/
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void setup()
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{
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}
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/*
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loop() continually scans the matrix, one row at a time.
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Each Row object strobes its strobePin and reads the readPins.
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And when a key press is detected, the row sends the key's scancode.
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scanDelay creates time intervals between matrix scans.
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The delay is needed so that the debouncer is not overwelmed.
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*/
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void loop()
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{
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row_0.process();
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row_1.process();
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scanDelay.delay();
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}
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