Data commit

Task/Morse-code/Lua/morse-code-1.lua

@@ -0,0 +1,93 @@
+local M = {}
+
+-- module-local variables
+local BUZZER = pio.PB_10
+local dit_length, dah_length, word_length
+
+-- module-local functions
+local buzz, dah, dit, init, inter_element_gap, medium_gap, pause, sequence, short_gap
+
+buzz = function(duration)
+  pio.pin.output(BUZZER)
+  pio.pin.setlow(BUZZER)
+  tmr.delay(tmr.SYS_TIMER, duration)
+  pio.pin.sethigh(BUZZER)
+  pio.pin.input(BUZZER)
+end
+
+dah = function()
+  buzz(dah_length)
+end
+
+dit = function()
+  buzz(dit_length)
+end
+
+init = function(baseline)
+  dit_length = baseline
+  dah_length = 2 * baseline
+  word_length = 4 * baseline
+end
+
+inter_element_gap = function()
+  pause(dit_length)
+end
+
+medium_gap = function()
+  pause(word_length)
+end
+
+pause = function(duration)
+  tmr.delay(tmr.SYS_TIMER, duration)
+end
+
+sequence = function(codes)
+  if codes then
+    for _,f in ipairs(codes) do
+      f()
+      inter_element_gap()
+    end
+    short_gap()
+  end
+end
+
+short_gap = function()
+  pause(dah_length)
+end
+
+local morse = {
+  a = { dit, dah }, b = { dah, dit, dit, dit }, c = { dah, dit, dah, dit },
+  d = { dah, dit, dit }, e = { dit }, f = { dit, dit, dah, dit },
+  g = { dah, dah, dit }, h = { dit, dit, dit ,dit }, i = { dit, dit },
+  j = { dit, dah, dah, dah }, k = { dah, dit, dah }, l = { dit, dah, dit, dit },
+  m = { dah, dah }, n = { dah, dit }, o = { dah, dah, dah },
+  p = { dit, dah, dah, dit }, q = { dah, dah, dit, dah }, r = { dit, dah, dit },
+  s = { dit, dit, dit }, t = { dah }, u = { dit, dit, dah },
+  v = { dit, dit, dit, dah }, w = { dit, dah, dah }, x = { dah, dit, dit, dah },
+  y = { dah, dit, dah, dah }, z = { dah, dah, dit, dit },
+
+  ["0"] = { dah, dah, dah, dah, dah }, ["1"] = { dit, dah, dah, dah, dah },
+  ["2"] = { dit, dit, dah, dah, dah }, ["3"] = { dit, dit, dit, dah, dah },
+  ["4"] = { dit, dit, dit, dit, dah }, ["5"] = { dit, dit, dit, dit, dit },
+  ["6"] = { dah, dit, dit, dit, dit }, ["7"] = { dah, dah, dit, dit, dit },
+  ["8"] = { dah, dah, dah, dit, dit }, ["9"] = { dah, dah, dah, dah, dit },
+
+  [" "] = { medium_gap }
+}
+
+-- public interface
+M.beep = function(message)
+  message = message:lower()
+  for _,ch in ipairs { message:byte(1, #message) } do
+    sequence(morse[string.char(ch)])
+  end
+end
+
+M.set_dit = function(duration)
+  init(duration)
+end
+
+-- initialization code
+init(50000)
+
+return M