diff --git a/IOSTM_CMSIS.cpp b/IOSTM_CMSIS.cpp
index b669d07..ce498d4 100644
--- a/IOSTM_CMSIS.cpp
+++ b/IOSTM_CMSIS.cpp
@@ -369,7 +369,9 @@ void CIO::interrupt()
 {
   uint8_t control  = MARK_NONE;
   uint16_t sample  = DC_OFFSET;
+#if defined(SEND_RSSI_DATA)
   uint16_t rawRSSI = 0U;
+#endif
   bitband_t eoc = (bitband_t)BITBAND_PERIPH(&ADC1->SR, ADC_SR_EOS_Pos);
   bitband_t adon = (bitband_t)BITBAND_PERIPH(&ADC1->CR2, ADC_CR2_ADON_Pos);
 #if defined(SEND_RSSI_DATA)
diff --git a/Makefile.CMSIS b/Makefile.CMSIS
index a4ee604..3573d6f 100644
--- a/Makefile.CMSIS
+++ b/Makefile.CMSIS
@@ -65,7 +65,7 @@ COMMON_FLAGS =-mthumb -mlittle-endian -mcpu=$(MCPU)
 COMMON_FLAGS+= -Wall
 COMMON_FLAGS+= -I. -I$(CMSISDIR)/Include -I$(CMSISDIR)/Device/ST/STM32F1xx/Include -I$(SYSDIR)
 COMMON_FLAGS+=  $(addprefix -I,$(INCDIR))
-COMMON_FLAGS+= -D$(MCU)
+COMMON_FLAGS+= -D$(MCU) -DMADEBYMAKEFILE
 COMMON_FLAGS+= -Os -flto -ffunction-sections -fdata-sections
 COMMON_FLAGS+= -g
 # Assembler flags
@@ -91,7 +91,7 @@ DEPENDS:=$(CSRC:%.c=$(OBJDIR)/%.d) $(CXXSRC:%.cpp=$(OBJDIR)/%.d)
 
 # Targets
 .PHONY: all
-all: $(DIS) $(HEX)
+all: GitVersion.h $(DIS) $(HEX)
 	$(SIZE) $(ELF)
 
 .PHONY: program
@@ -116,7 +116,7 @@ debug: $(ELF)
 
 .PHONY: clean
 clean:
-	$(RM) $(OBJ) $(HEX) $(ELF) $(DIS) $(MAP) $(DEPENDS)
+	$(RM) $(OBJ) $(HEX) $(ELF) $(DIS) $(MAP) $(DEPENDS) GitVersion.h
 
 # implicit rules
 .elf.hex:
@@ -149,3 +149,17 @@ $(DIS): $(ELF)
 
 # include dependecies
 -include $(DEPENDS)
+
+# Export the current git version if the index file exists, else 000...
+GitVersion.h:
+ifdef SYSTEMROOT
+	echo #define GITVERSION "0000000" > $@
+else ifdef SystemRoot
+	echo #define GITVERSION "0000000" > $@
+else
+ifneq ("$(wildcard .git/index)","")
+	echo "#define GITVERSION \"$(shell git rev-parse --short HEAD)\"" > $@
+else
+	echo "#define GITVERSION \"0000000\"" > $@
+endif
+endif
diff --git a/P25Defines.h b/P25Defines.h
index e4fa287..bb44914 100644
--- a/P25Defines.h
+++ b/P25Defines.h
@@ -47,6 +47,11 @@ const unsigned int P25_TSDU_FRAME_LENGTH_BITS      = P25_TSDU_FRAME_LENGTH_BYTES
 const unsigned int P25_TSDU_FRAME_LENGTH_SYMBOLS   = P25_TSDU_FRAME_LENGTH_BYTES * 4U; 
 const unsigned int P25_TSDU_FRAME_LENGTH_SAMPLES   = P25_TSDU_FRAME_LENGTH_SYMBOLS * P25_RADIO_SYMBOL_LENGTH;
 
+const unsigned int P25_PDU_HDR_FRAME_LENGTH_BYTES = 45U;
+const unsigned int P25_PDU_HDR_FRAME_LENGTH_BITS = P25_PDU_HDR_FRAME_LENGTH_BYTES * 8U;
+const unsigned int P25_PDU_HDR_FRAME_LENGTH_SYMBOLS = P25_PDU_HDR_FRAME_LENGTH_BYTES * 4U;
+const unsigned int P25_PDU_HDR_FRAME_LENGTH_SAMPLES = P25_PDU_HDR_FRAME_LENGTH_SYMBOLS * P25_RADIO_SYMBOL_LENGTH;
+
 const unsigned int P25_SYNC_LENGTH_BYTES   = 6U;
 const unsigned int P25_SYNC_LENGTH_BITS    = P25_SYNC_LENGTH_BYTES * 8U;
 const unsigned int P25_SYNC_LENGTH_SYMBOLS = P25_SYNC_LENGTH_BYTES * 4U;
diff --git a/P25RX.cpp b/P25RX.cpp
index 54d4237..d322db0 100644
--- a/P25RX.cpp
+++ b/P25RX.cpp
@@ -199,7 +199,19 @@ void CP25RX::processHdr(q15_t sample)
                 serial.writeP25Hdr(frame, P25_HDR_FRAME_LENGTH_BYTES + 1U);
             }
             break;
-        case P25_DUID_TSDU: {
+		case P25_DUID_PDU: {
+				calculateLevels(m_hdrSyncPtr, P25_PDU_HDR_FRAME_LENGTH_SYMBOLS);
+
+				DEBUG4("P25RX: sync found in PDU pos/centre/threshold", m_hdrSyncPtr, m_centreVal, m_thresholdVal);
+
+				uint8_t frame[P25_PDU_HDR_FRAME_LENGTH_BYTES + 1U];
+				samplesToBits(m_hdrSyncPtr, P25_PDU_HDR_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centreVal, m_thresholdVal);
+
+				frame[0U] = 0x01U;
+				serial.writeP25Hdr(frame, P25_PDU_HDR_FRAME_LENGTH_BYTES + 1U);
+			}
+			break;
+		case P25_DUID_TSDU: {
                 calculateLevels(m_hdrStartPtr, P25_TSDU_FRAME_LENGTH_SYMBOLS);
 
                 DEBUG4("P25RX: sync found in TSDU pos/centre/threshold", m_hdrSyncPtr, m_centreVal, m_thresholdVal);
diff --git a/SerialPort.cpp b/SerialPort.cpp
index 9c47cba..daf9a1e 100644
--- a/SerialPort.cpp
+++ b/SerialPort.cpp
@@ -103,7 +103,7 @@ const uint8_t MMDVM_DEBUG5       = 0xF5U;
 const char HARDWARE[] = concat(HW_TYPE, DESCRIPTION, TCXO, GITVERSION);
 #else
 #define concat(h, a, b, c, d) h " " a " " b " (Build: " c " " d ")"
-const char HARDWARE[] = concat(DESCRIPTION, TCXO, __TIME__, __DATE__);
+const char HARDWARE[] = concat(HW_TYPE, DESCRIPTION, TCXO, __TIME__, __DATE__);
 #endif
 
 const uint8_t PROTOCOL_VERSION   = 1U;
diff --git a/SerialRB.h b/SerialRB.h
index ee244d2..7b6b7b9 100644
--- a/SerialRB.h
+++ b/SerialRB.h
@@ -32,11 +32,7 @@ Boston, MA  02110-1301, USA.
 #include <Arduino.h>
 #endif
 
-#if defined(STM32F105xC) || defined(__MK20DX256__)
 const uint16_t SERIAL_RINGBUFFER_SIZE = 370U;
-#else
-const uint16_t SERIAL_RINGBUFFER_SIZE = 1000U;
-#endif
 
 class CSerialRB {
 public: