diff --git a/FM.cpp b/FM.cpp
index 6fb513a..9c25d83 100644
--- a/FM.cpp
+++ b/FM.cpp
@@ -20,10 +20,8 @@
 #include "Globals.h"
 #include "FM.h"
 
-const uint8_t BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U};
-
-#define WRITE_BIT_AUDIO(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE[(i)&7])
-#define READ_BIT_AUDIO(p,i)    (p[(i)>>3] & BIT_MASK_TABLE[(i)&7])
+const uint16_t FM_TX_BLOCK_SIZE = 250U;
+const uint16_t FM_SERIAL_BLOCK_SIZE = 127U;
 
 CFM::CFM() :
 m_callsign(),
@@ -154,39 +152,51 @@ void CFM::samples(bool cos, const q15_t* samples, uint8_t length)
 
 void CFM::process()
 {
-  if (io.getSpace() > 2 && (m_outputRFRB.getData() >= 250 || m_state != STATE_FM)) {//if we just left FM mode, so write all what is left in buffer, regardless of the amoutn of data
-    uint16_t length = m_outputRFRB.getData();
-    uint16_t space = io.getSpace() - 2;
+  q15_t sample;
+  while (io.getSpace() >= 3U && m_outputRFRB.get(sample))
+    io.write(STATE_FM, &sample, 1U);
 
-    if(length > space)
-      length = space;
+  // if (io.getSpace() > 2 && (m_outputRFRB.getData() >= FM_TX_BLOCK_SIZE || m_state != STATE_FM)) {//if we just left FM mode, so write all what is left in buffer, regardless of the amoutn of data
+  //   uint16_t length = m_outputRFRB.getData();
+  //   uint16_t space = io.getSpace() - 2;
 
-    q15_t samples[length];
-    for(uint16_t i = 0; i < length; i++) {
-      q15_t sample = 0;
-      m_outputRFRB.get(sample);
-      samples[i] = sample;
-    }
+  //   if(length > FM_TX_BLOCK_SIZE)
+  //     length = FM_TX_BLOCK_SIZE;
+  //   if(space > FM_TX_BLOCK_SIZE)
+  //     space = FM_TX_BLOCK_SIZE;
+  //   if(length > space)
+  //     length = space;
 
-    io.write(STATE_FM, samples, length);
-  }
+  //   q15_t samples[FM_TX_BLOCK_SIZE];
+  //   for(uint16_t i = 0; i < length; i++) {
+  //     q15_t sample = 0;
+  //     m_outputRFRB.get(sample);
+  //     samples[i] = sample;
+  //   }
 
-  //Write audio to serial
-  if (m_downsampler.getData() >= 127 || m_state != STATE_FM) {//if we just left FM mode, so write all what is left in buffer, regardless of the amoutn of data
-    uint16_t length = m_downsampler.getData();
+  //   io.write(STATE_FM, samples, length);
+  // }
 
-    if(length > 127U)//max message size on serial is 127
-      length = 127U;
+  // //Write audio to serial
+  // if (m_downsampler.getData() >= 127 || m_state != STATE_FM) {//if we just left FM mode, so write all what is left in buffer, regardless of the amoutn of data
+  //   uint16_t length = m_downsampler.getData();
 
-    uint8_t serialSamples[length];
+  //   if(length > FM_SERIAL_BLOCK_SIZE)//max message size on serial is 127
+  //     length = FM_SERIAL_BLOCK_SIZE;
 
-    for(uint16_t i = 0U; i < length; i++) {
-      uint8_t serialSample = 0U;
-      m_downsampler.getPackedData(serialSample);
-      serialSamples[i] = serialSample;
-    }
-    serial.writeFMData(serialSamples, length);
-  }
+  //   if(length > FM_SERIAL_BLOCK_SIZE)
+  //     length = FM_SERIAL_BLOCK_SIZE;
+
+  //   uint8_t serialSamples[FM_SERIAL_BLOCK_SIZE];
+
+  //   for(uint16_t i = 0U; i < length; i++) {
+  //     uint8_t serialSample = 0U;
+  //     m_downsampler.getPackedData(serialSample);
+  //     serialSamples[i] = serialSample;
+  //   }
+
+  //   serial.writeFMData(serialSamples, length);
+  // }
 }
 
 void CFM::reset()