Berry example: wave file recorder (#21315)

tasmota/berry/audio/wavrec.be

@@ -0,0 +1,73 @@
+#-
+ - WAV recorder driver  Berry - mono only
+ - used from command `wavrec<duration in seconds> <file_name_without_wav_suffix>`
+-#
+
+class WAVREC
+  var in, f
+  var fast
+  var targetSize
+
+  def init(seconds, name)
+    self.in=AudioInputI2S()
+    self.in.begin()
+    self.in.set_gain(60)
+    var r = self.in.get_rate()
+    var bps = self.in.get_bits_per_sample()
+    log(f"WAV: sample rate {r} with {bps} bits")
+    self.f = open(f"{name}.wav", "w")
+    self.targetSize = r * seconds * (bps/8)
+    self.writeHeader(self.targetSize,r, bps)
+    log(f"WAV: will record {seconds} seconds to {name}.wav")
+    self.fast = /->self.record()
+    tasmota.add_fast_loop(self.fast)
+    tasmota.add_driver(self)
+  end
+
+  def record()
+    var b = self.in.read_bytes()
+    if b == nil
+      return
+    end
+    self.targetSize -= size(b)
+    if self.targetSize > 0
+      self.f.write(b)
+    else
+      tasmota.remove_fast_loop(self.fast)
+      self.f.close()
+      log("WAV: closing file")
+      tasmota.remove_driver(self)
+    end
+  end
+
+  def writeHeader(fsize, rate, bps)
+    var header = bytes(44)
+    header.."RIFF"
+    header.add(fsize + 44,4)
+    header.."WAVE"
+    header.."fmt "
+    header.add(bps,4) #sample_bits
+    header..1 # PCM
+    header..0
+    header..1 # mono
+    header..0
+    header.add(rate,4) #sample_bits
+    header.add(rate * 2,4) #(Sample Rate * BitsPerSample * Channels) / 8
+    header..2 # BlockAlign
+    header..0
+    header..bps # sample bits
+    header..0
+    header.."data"
+    header.add(fsize,4) #sample_bits
+    self.f.write(header)
+  end
+
+end
+
+def wav_recorder(cmd, idx, payload, payload_json)
+  tasmota.resp_cmnd_done()
+  return WAVREC(idx, payload)
+end
+
+tasmota.add_cmd('wavrec', wav_recorder)
+# use like: waverec5 /test - > record 5 seconds to /test.wav