(almost) One loop to rule all the samples

Avoid looping over and over the samples. One

FMTimeout.cpp

@@ -62,6 +62,26 @@ void CFMTimeout::getAudio(q15_t* samples, uint8_t length)
   }
 }
 
+q15_t CFMTimeout::getAudio(q15_t sample)
+{
+  if (m_pos > 12000U) {
+    q31_t sample = BUSY_AUDIO[m_n] * m_level;
+    sample = q15_t(__SSAT((sample >> 15), 16));
+
+    m_n++;
+    if (m_n >= BUSY_AUDIO_LEN)
+      m_n = 0U;
+  } else {
+    sample = 0U;
+  }
+
+  m_pos++;
+  if (m_pos >= 24000U)
+    m_pos = 0U;
+
+    return sample;
+}
+
 void CFMTimeout::start()
 {
   m_running = true;