Morse code sample application

source/samples/MorseCode.cpp

@@ -0,0 +1,185 @@
+#include "Tests.h"
+
+#include <cctype>
+
+// Based off: https://github.com/WarwickDCSiLab/arduino-morse-code/blob/master/morse.ino
+
+// Morse code timing constants
+// Time differences come from the international standard
+constexpr int FRAME_LENGTH = 280;
+constexpr int MAX_FRAME_LENGTH = 500;
+constexpr int MIN_FRAME_LENGTH = 10;
+
+static_assert(FRAME_LENGTH >= MIN_FRAME_LENGTH);
+static_assert(FRAME_LENGTH <= MAX_FRAME_LENGTH);
+
+#define DOT_TIME FRAME_LENGTH
+#define DASH_TIME DOT_TIME*3
+#define INNER_SEP_TIME DOT_TIME*1
+#define LETTER_SEP_TIME DOT_TIME*3
+#define WORD_SEP_TIME DOT_TIME*7
+
+// Morse symbol values
+constexpr int term = 0;
+constexpr int dit = 1;
+constexpr int dah = 2;
+
+// Morse letter definitions
+constexpr int A[] = { dit, dah, term };
+constexpr int B[] = { dah, dit, dit, dit, term };
+constexpr int C[] = { dah, dit, dah, dit, term };
+constexpr int D[] = { dah, dit, dit, term };
+constexpr int E[] = { dit, term };
+constexpr int F[] = { dit, dit, dah, dit, term };
+constexpr int G[] = { dah, dah, dit, term };
+constexpr int H[] = { dit, dit, dit, dit, term };
+constexpr int I[] = { dit, dit, term };
+constexpr int J[] = { dit, dah, dah, dah, term };
+constexpr int K[] = { dah, dit, dah, term };
+constexpr int L[] = { dit, dah, dit, dit, term };
+constexpr int M[] = { dah, dah, term };
+constexpr int N[] = { dah, dit, term };
+constexpr int O[] = { dah, dah, dah, term };
+constexpr int P[] = { dit, dah, dah, dit, term };
+constexpr int Q[] = { dah, dah, dit, dah, term };
+constexpr int R[] = { dit, dah, dit, term };
+constexpr int S[] = { dit, dit, dit, term };
+constexpr int T[] = { dah, term };
+constexpr int U[] = { dit, dit, dah, term };
+constexpr int V[] = { dit, dit, dit, dah, term };
+constexpr int W[] = { dit, dah, dah, term };
+constexpr int X[] = { dah, dit, dit, dah, term };
+constexpr int Y[] = { dah, dit, dah, dah, term };
+constexpr int Z[] = { dah, dah, dit, dit, term };
+
+const int* morse_code_letters[] =
+{
+    A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z
+};
+
+const char* morse_code_numbers[] =
+{
+    "ZERO",
+    "ONE",
+    "TWO",
+    "THREE",
+    "FOUR",
+    "FIVE",
+    "SIX",
+    "SEVEN",
+    "EIGHT",
+    "NINE"
+};
+
+constexpr int C5 = 523;
+
+// From source/samples/AudioTest.cpp
+static void analogPitch(int frequency) {
+    constexpr uint8_t pitchVolume = 0xA0;
+
+    if (frequency <= 0 || pitchVolume == 0) {
+        uBit.audio.virtualOutputPin.setAnalogValue(0);
+    } else {
+        // I don't understand the logic of this value.
+        // It is much louder on the real pin.
+        int v = 1 << (pitchVolume >> 5);
+        // If you flip the order of these they crash on the real pin with E030.
+        uBit.audio.virtualOutputPin.setAnalogValue(v);
+        uBit.audio.virtualOutputPin.setAnalogPeriodUs(1000000/frequency);
+    }
+}
+
+static void on()
+{
+    analogPitch(C5);
+    uBit.io.col1.setDigitalValue(0);
+    uBit.io.col2.setDigitalValue(0);
+    uBit.io.col3.setDigitalValue(0);
+    uBit.io.col4.setDigitalValue(0);
+    uBit.io.col5.setDigitalValue(0);
+}
+
+static void off()
+{
+    uBit.io.col1.setDigitalValue(1);
+    uBit.io.col2.setDigitalValue(1);
+    uBit.io.col3.setDigitalValue(1);
+    uBit.io.col4.setDigitalValue(1);
+    uBit.io.col5.setDigitalValue(1);
+
+    uBit.audio.virtualOutputPin.setAnalogValue(0);
+}
+
+// Outputs a single letter of a word from array constants
+static void blinkLetter(const int* morse)
+{
+    int i = 0;
+    while (morse[i] != term)
+    {
+        switch (morse[i])
+        {
+        case dit:
+            on();
+            uBit.sleep(DOT_TIME);
+            off();
+            uBit.sleep(INNER_SEP_TIME);
+            break;
+        case dah:
+            on();
+            uBit.sleep(DASH_TIME);
+            off();
+            uBit.sleep(INNER_SEP_TIME);
+            break;
+        }
+        i++;
+    }
+
+    uBit.sleep(LETTER_SEP_TIME);
+}
+
+// Convert single digit to Morse Code
+static void blinkDigit(int n)
+{
+    const char* letters = morse_code_numbers[n];
+    const size_t letters_length = strlen(letters);
+    for(size_t i = 0; i < letters_length; i++)
+    {
+        blinkLetter(morse_code_letters[letters[i]-'A']);
+    }
+    uBit.sleep(WORD_SEP_TIME);
+}
+
+void morse_code()
+{
+    const char message[] = "LANCASHIRE";
+
+    uBit.display.disable();
+    uBit.io.row1.setDigitalValue(1);
+    uBit.io.row2.setDigitalValue(1);
+    uBit.io.row3.setDigitalValue(1);
+    uBit.io.row4.setDigitalValue(1);
+    uBit.io.row5.setDigitalValue(1);
+
+    while (true)
+    {
+        for (char ch : message)
+        {
+            if (isdigit(ch))
+            {
+                blinkDigit(ch - '0');
+            }
+            else if (isalpha(ch))
+            {
+                ch = (char)toupper(ch);
+                blinkLetter(morse_code_letters[ch - 'A']);
+            }
+            else
+            {
+                // Skip
+            }
+        }
+
+        // Wait before starting again
+        uBit.sleep(5 * 1000);
+    }
+}

source/samples/Tests.h

@@ -105,5 +105,6 @@ void stream_test_getValue_interval();
 void stream_test_record();
 void stream_test_recording_sample_rates();
 void stream_test_all();
+void morse_code();
 
 #endif