diff --git a/Globals.h b/Globals.h
index 1e0b04c..68f0fbe 100644
--- a/Globals.h
+++ b/Globals.h
@@ -146,10 +146,11 @@ extern CIO io;
 
 #if defined(MODE_OLED)
 extern CI2COLED oled;
+extern CI2CPort i2C3;
 #endif
 
 #if defined(I2C_REPEATER)
-extern CI2CPort i2c1;
+extern CI2CPort i2C1;
 #endif
 
 #if defined(MODE_DSTAR)
diff --git a/I2COLED.cpp b/I2COLED.cpp
index da3c156..4706735 100644
--- a/I2COLED.cpp
+++ b/I2COLED.cpp
@@ -21,6 +21,7 @@
 #if defined(MODE_OLED)
 
 #include "I2COLED.h"
+#include "I2CPort.h"
 
 #include "Globals.h"
 
@@ -304,7 +305,6 @@ const uint8_t FONT[] = {
 
 
 CI2COLED::CI2COLED() :
-m_i2c(3U),
 m_oledBuffer(NULL)
 {
   m_oledBuffer = new uint8_t[OLED_BUFFER_SIZE];
@@ -314,7 +314,7 @@ m_oledBuffer(NULL)
 
 bool CI2COLED::init()
 {
-  bool ret = m_i2c.init();
+  bool ret = i2C3.init();
   if (!ret)
     return false;
 
@@ -409,7 +409,7 @@ void CI2COLED::sendCommand(uint8_t c0, uint8_t c1, uint8_t c2)
   buff[4U] = c2;
 
   // Write Data on I2C
-  m_i2c.write(buff, 5U);
+  i2C3.write(buff, 5U);
 }
 
 void CI2COLED::sendCommand(uint8_t c0, uint8_t c1)
@@ -422,7 +422,7 @@ void CI2COLED::sendCommand(uint8_t c0, uint8_t c1)
   buff[3U] = c1;
 
   // Write Data on I2C
-  m_i2c.write(buff, 4U);
+  i2C3.write(buff, 4U);
 }
 
 void CI2COLED::sendCommand(uint8_t c)
@@ -434,7 +434,7 @@ void CI2COLED::sendCommand(uint8_t c)
   buff[2U] = c;
 
   // Write Data on I2C
-  m_i2c.write(buff, 3U);
+  i2C3.write(buff, 3U);
 }
 
 void CI2COLED::sendData(const uint8_t* data, uint16_t length)
@@ -445,8 +445,8 @@ void CI2COLED::sendData(const uint8_t* data, uint16_t length)
   buff[1U] = SSD_Data_Mode;
 
   // Write Data on I2C
-  m_i2c.write(buff, 2U);
-  m_i2c.write(data, length);
+  i2C3.write(buff, 2U);
+  i2C3.write(data, length);
 }
 
 void CI2COLED::clear()
diff --git a/I2COLED.h b/I2COLED.h
index 928788e..b95735d 100644
--- a/I2COLED.h
+++ b/I2COLED.h
@@ -25,8 +25,6 @@
 
 #include <cstdint>
 
-#include "I2CPort.h"
-
 class CI2COLED {
 public:
   CI2COLED();
@@ -36,7 +34,6 @@ public:
   void setMode(int state);
 
 private:
-  CI2CPort m_i2c;
   uint8_t* m_oledBuffer;
 
   void write(const char* text);
diff --git a/I2CPort.cpp b/I2CPort.cpp
index be7ffea..5034ede 100644
--- a/I2CPort.cpp
+++ b/I2CPort.cpp
@@ -1,3 +1,4 @@
+
 /*
  *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
@@ -30,9 +31,54 @@
 #include "stm32f7xx_i2c.h"
 #endif
 
+#include "Globals.h"
+
 const uint32_t I2C_CLK_FREQ = 100000U;	// XXX FIXME
 const uint16_t I2C_ADDR     = 0U;		// XXX FIXME
 
+
+extern "C" {
+#if defined(I2C_REPEATER)
+  void I2C1_EV_IRQHandler(void)
+  {
+    i2C1.eventHandler();
+  }
+
+  void I2C1_ER_IRQHandler(void)
+  {
+    if (I2C_GetITStatus(I2C1, I2C_IT_AF))
+      I2C_ClearITPendingBit(I2C1, I2C_IT_AF);
+  }
+#endif
+
+#ifdef notdef
+  void I2C2_EV_IRQHandler(void)
+  {
+    i2C2.eventHandler();
+  }
+
+  void I2C2_ER_IRQHandler(void)
+  {
+    if (I2C_GetITStatus(I2C2, I2C_IT_AF))
+      I2C_ClearITPendingBit(I2C2, I2C_IT_AF);
+  }
+#endif
+
+#if defined(MODE_OLED)
+  void I2C3_EV_IRQHandler(void)
+  {
+    i2C3.eventHandler();
+  }
+
+  void I2C3_ER_IRQHandler(void)
+  {
+    if (I2C_GetITStatus(I2C3, I2C_IT_AF))
+      I2C_ClearITPendingBit(I2C3, I2C_IT_AF);
+  }
+#endif
+}
+
+
 CI2CPort::CI2CPort(uint8_t n) :
 m_n(n),
 m_ok(false),
@@ -129,6 +175,75 @@ uint8_t CI2CPort::write(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
+void CI2CPort::eventHandler()
+{
+  I2C_TypeDef* i2CPort = NULL;
+
+  switch (m_n) {
+    case 1U:
+      i2CPort = I2C1;
+      break;
+    case 2U:
+      i2CPort = I2C2;
+      break;
+    case 3U:
+      i2CPort = I2C3;
+      break;
+    default:
+      return;
+  }
+
+  uint32_t event = I2C_GetLastEvent(i2CPort);
+
+  switch (event) {
+    case I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED:
+    case I2C_EVENT_SLAVE_BYTE_TRANSMITTED:
+      if (fifoLevel() > 0U) {
+        I2C_SendData(i2CPort, m_fifo[m_fifoTail]);
+        m_fifoTail++;
+        if (m_fifoTail >= I2C_TX_FIFO_SIZE)
+          m_fifoTail = 0U;
+      } else
+        I2C_SendData(i2CPort, 0U);
+      break;
+
+    case I2C_EVENT_SLAVE_STOP_DETECTED:
+      clearFlag();
+      break;
+  }
+}
+
+void CI2CPort::clearFlag()
+{
+  I2C_TypeDef* i2CPort = NULL;
+
+  switch (m_n) {
+    case 1U:
+      i2CPort = I2C1;
+      break;
+    case 2U:
+      i2CPort = I2C2;
+      break;
+    case 3U:
+      i2CPort = I2C3;
+      break;
+    default:
+      return;
+  }
+
+  // Clear ADDR flag
+  while((i2CPort->SR1 & I2C_SR1_ADDR) == I2C_SR1_ADDR) {
+    i2CPort->SR1;
+    i2CPort->SR2;
+  }
+
+  // Clear STOPF flag
+  while((i2CPort->SR1 & I2C_SR1_STOPF) == I2C_SR1_STOPF) {
+    i2CPort->SR1;
+    i2CPort->CR1 |= 0x1;
+  }
+}
+
 uint16_t CI2CPort::fifoLevel()
 {
   uint32_t tail = m_fifoTail;
diff --git a/I2CPort.h b/I2CPort.h
index a6c12be..9e525ed 100644
--- a/I2CPort.h
+++ b/I2CPort.h
@@ -36,6 +36,8 @@ public:
 
   uint8_t write(const uint8_t* data, uint8_t length);
 
+  void eventHandler();
+
 private:
   uint8_t m_n;
   bool    m_ok;
@@ -45,6 +47,7 @@ private:
 
   uint16_t fifoLevel();
   bool     fifoPut(uint8_t next);
+  void     clearFlag();
 };
 
 #endif
diff --git a/IOSTM.cpp b/IOSTM.cpp
index 62f6582..ab5570c 100644
--- a/IOSTM.cpp
+++ b/IOSTM.cpp
@@ -196,7 +196,7 @@ void CIO::initInt()
 #endif
 
 #if defined(I2C_REPEATER)
-  i2c1.init();
+  i2C1.init();
 #endif
 }
 
diff --git a/MMDVM.cpp b/MMDVM.cpp
index a4a3593..a3f39ac 100644
--- a/MMDVM.cpp
+++ b/MMDVM.cpp
@@ -43,10 +43,11 @@ bool m_dcd = false;
 
 #if defined(MODE_OLED)
 CI2COLED oled;
+CI2CPort i2C3(3U);
 #endif
 
 #if defined(I2C_REPEATER)
-CI2CPort i2c1(1U);
+CI2CPort i2C1(1U);
 #endif
 
 #if defined(MODE_DSTAR)
diff --git a/MMDVM.ino b/MMDVM.ino
index cd63b42..c119fb8 100644
--- a/MMDVM.ino
+++ b/MMDVM.ino
@@ -40,6 +40,7 @@ bool m_dcd = false;
 
 #if defined(MODE_OLED)
 CI2COLED oled;
+CI2CPort i2C3(3U);
 #endif
 
 #if defined(I2C_REPEATER)
diff --git a/SerialPort.cpp b/SerialPort.cpp
index 5c01c35..13c5ae8 100644
--- a/SerialPort.cpp
+++ b/SerialPort.cpp
@@ -1313,7 +1313,7 @@ void CSerialPort::processMessage(uint8_t type, const uint8_t* buffer, uint16_t l
 
 #if defined(I2C_REPEATER)
     case MMDVM_I2C_DATA: {
-        err = i2c1.write(buffer, length);
+        err = i2C1.write(buffer, length);
         if (err != 0U) {
           DEBUG2("Received invalid I2C data", err);
           sendNAK(err);
diff --git a/Version.h b/Version.h
index 0972132..7c3f717 100644
--- a/Version.h
+++ b/Version.h
@@ -19,7 +19,6 @@
 #if !defined(VERSION_H)
 #define  VERSION_H
 
-#define VERSION "20201120"
+#define VERSION "20201123"
 
 #endif
-