diff --git a/IODevice.h b/IODevice.h
index 74fe49b..d12fafd 100644
--- a/IODevice.h
+++ b/IODevice.h
@@ -542,8 +542,10 @@ protected:
 #include "IO_MCP23017.h"
 #include "IO_PCF8574.h"
 #include "IO_PCF8575.h"
+#include "IO_PCA9555.h"
 #include "IO_duinoNodes.h"
 #include "IO_EXIOExpander.h"
+#include "IO_trainbrains.h"
 
 
 #endif // iodevice_h
diff --git a/IO_trainbrains.h b/IO_trainbrains.h
new file mode 100644
index 0000000..058fe02
--- /dev/null
+++ b/IO_trainbrains.h
@@ -0,0 +1,98 @@
+/*
+ *  © 2023, Chris Harlow. All rights reserved.
+ *  © 2021, Neil McKechnie. All rights reserved.
+ *  
+ *  This file is part of DCC++EX API
+ *
+ *  This is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  It is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with CommandStation.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef io_trainbrains_h
+#define io_trainbrains_h
+
+#include "IO_GPIOBase.h"
+#include "FSH.h"
+
+/////////////////////////////////////////////////////////////////////////////////////////////////////
+/*
+ * IODevice subclass for trainbrains 3-block occupancy detector.
+ * For details see http://trainbrains.eu
+ */
+ 
+ enum TrackUnoccupancy
+{
+    TRACK_UNOCCUPANCY_UNKNOWN = 0,
+    TRACK_OCCUPIED = 1,
+    TRACK_UNOCCUPIED = 2
+};
+
+class Trainbrains02 : public GPIOBase<uint16_t> {
+public:
+  static void create(VPIN vpin, uint8_t nPins, I2CAddress i2cAddress) {
+    if (checkNoOverlap(vpin, nPins, i2cAddress)) new Trainbrains02(vpin, nPins, i2cAddress);
+  }
+
+private:  
+  // Constructor
+  Trainbrains02(VPIN vpin, uint8_t nPins, I2CAddress i2cAddress, int interruptPin=-1) 
+    : GPIOBase<uint16_t>((FSH *)F("Trainbrains02"), vpin, nPins, i2cAddress, interruptPin) 
+  {
+    requestBlock.setRequestParams(_I2CAddress, inputBuffer, sizeof(inputBuffer),
+      outputBuffer, sizeof(outputBuffer));
+    
+     outputBuffer[0] = (uint8_t)_I2CAddress; // strips away the mux part.
+     outputBuffer[1] =14;
+     outputBuffer[2] =1;
+     outputBuffer[3] =0;  // This is the channel updated at each poling call
+     outputBuffer[4] =0;
+     outputBuffer[5] =0;
+     outputBuffer[6] =0;
+     outputBuffer[7] =0;
+     outputBuffer[8] =0;
+     outputBuffer[9] =0;
+  }
+  
+  void _writeGpioPort() override {}
+
+  void _readGpioPort(bool immediate) override {
+    // cycle channel on device each time 
+    outputBuffer[3]=channelInProgress+1; // 1-origin 
+    channelInProgress++;
+    if(channelInProgress>=_nPins) channelInProgress=0; 
+    
+    if (immediate) {
+      _processCompletion(I2CManager.read(_I2CAddress, inputBuffer, sizeof(inputBuffer), 
+                                   outputBuffer, sizeof(outputBuffer)));
+    } else {
+      // Queue new request
+      requestBlock.wait(); // Wait for preceding operation to complete
+      // Issue new request to read GPIO register
+      I2CManager.queueRequest(&requestBlock);
+    }
+  }
+
+  // This function is invoked when an I/O operation on the requestBlock completes.
+  void _processCompletion(uint8_t status) override {
+    if (status != I2C_STATUS_OK) inputBuffer[6]=TRACK_UNOCCUPANCY_UNKNOWN;  
+    if (inputBuffer[6] == TRACK_UNOCCUPIED ) _portInputState |=  0x01 <<channelInProgress;
+    else _portInputState &=  ~(0x01 <<channelInProgress);
+  }
+
+  uint8_t channelInProgress=0; 
+  uint8_t outputBuffer[10];
+  uint8_t inputBuffer[10];
+  
+};
+
+#endif
\ No newline at end of file
diff --git a/version.h b/version.h
index 2d89cd0..3937937 100644
--- a/version.h
+++ b/version.h
@@ -3,7 +3,9 @@
 
 #include "StringFormatter.h"
 
-#define VERSION "5.2.9"
+#define VERSION "5.2.10"
+// 5.2.10 - Include trainbrains.eu block unoccupancy driver
+//        - include IO_PCA9555  
 // 5.2.9  - Bugfix LCD startup with no LCD, uses <@
 // 5.2.9  - EXRAIL STASH feature 
 // 5.2.8  - Bugfix: Do not turn off all tracks on change