IO_CMRI.cpp

@@ -0,0 +1,324 @@
+/*
+ *  © 2023, 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/>.
+ */
+
+#include "IO_CMRI.h"
+#include "defines.h"
+
+/************************************************************
+ * CMRIbus implementation
+ ************************************************************/
+
+// Constructor for CMRIbus
+CMRIbus::CMRIbus(uint8_t busNo, HardwareSerial &serial, unsigned long baud, uint16_t cycleTimeMS, VPIN transmitEnablePin) {
+  _busNo = busNo;
+  _serial = &serial;
+  _baud = baud;
+  _cycleTime = cycleTimeMS * 1000UL; // convert from milliseconds to microseconds.
+  _transmitEnablePin = transmitEnablePin;
+  if (_transmitEnablePin != VPIN_NONE) {
+    pinMode(_transmitEnablePin, OUTPUT);
+    ArduinoPins::fastWriteDigital(_transmitEnablePin, 0); // transmitter initially off
+  }
+
+  // Max message length is 256+6=262 bytes.  
+  // Each byte is one start bit, 8 data bits and 1 or 2 stop bits, assume 11 bits per byte.  
+  // Calculate timeout based on treble this time.
+  _timeoutPeriod = 3 * 11 * 262 * 1000UL / (_baud / 1000UL);
+#if defined(ARDUINOCMRI_COMPATIBLE)
+  // NOTE: The ArduinoCMRI library, unless modified, contains a 'delay(50)' between 
+  // receiving the end of the prompt message and starting to send the response.  This
+  // is allowed for below.
+  _timeoutPeriod += 50000UL;
+#endif
+  
+  // Calculate the time in microseconds to transmit one byte (11 bits max).
+  _byteTransmitTime = 1000000UL * 11 / _baud;
+  // Postdelay is only required if we need to allow for data still being sent when
+  // we want to switch off the transmitter.  The flush() method of HardwareSerial
+  // ensures that the data has completed being sent over the line.
+  _postDelay = 0;
+  
+  // Add device to HAL device chain
+  IODevice::addDevice(this);
+
+  // Add bus to CMRIbus chain.
+  _nextBus = _busList;
+  _busList = this;
+}
+
+
+// Main loop function for CMRIbus.
+// Work through list of nodes.  For each node, in separate loop entries
+// send initialisation message (once only);  then send
+// output message;  then send prompt for input data, and 
+// process any response data received.
+// When the slot time has finished, move on to the next device.
+void CMRIbus::_loop(unsigned long currentMicros) {
+  
+  _currentMicros = currentMicros;
+
+  while (_serial->available())
+    processIncoming();
+
+  // Send any data that needs sending.
+  processOutgoing();
+
+}
+
+// Send output data to the bus for nominated CMRInode
+uint16_t CMRIbus::sendData(CMRInode *node) {
+  uint16_t numDataBytes = (node->getNumOutputs()+7)/8;
+  _serial->write(SYN);
+  _serial->write(SYN);
+  _serial->write(STX);
+  _serial->write(node->getNodeID() + 65);
+  _serial->write('T'); // T for Transmit data message
+  uint16_t charsSent = 6; // include header and trailer
+  for (uint8_t index=0; index<numDataBytes; index++) {
+    uint8_t value = node->getOutputStates(index);
+    if (value == DLE || value == STX || value == ETX) {
+      _serial->write(DLE); 
+      charsSent++;
+    }
+    _serial->write(value);
+    charsSent++;
+  }
+  _serial->write(ETX);
+  return charsSent;  // number of characters sent
+}
+
+// Send request for input data to nominated CMRInode.
+uint16_t CMRIbus::requestData(CMRInode *node) {
+  _serial->write(SYN);
+  _serial->write(SYN);
+  _serial->write(STX);
+  _serial->write(node->getNodeID() + 65);
+  _serial->write('P'); // P for Poll message
+  _serial->write(ETX);
+  return 6;  // number of characters sent
+}
+
+// Send initialisation message
+uint16_t CMRIbus::sendInitialisation(CMRInode *node) {
+  _serial->write(SYN);
+  _serial->write(SYN);
+  _serial->write(STX);
+  _serial->write(node->getNodeID() + 65);
+  _serial->write('I'); // I for initialise message
+  _serial->write(node->getType());  // NDP
+  _serial->write((uint8_t)0);  // dH
+  _serial->write((uint8_t)0);  // dL
+  _serial->write((uint8_t)0);  // NS
+  _serial->write(ETX);
+  return 10;  // number of characters sent
+}
+
+void CMRIbus::processOutgoing() {
+  uint16_t charsSent = 0;
+  if (_currentNode == NULL) {
+    // If we're between read/write cycles then don't do anything else.
+    if (_currentMicros - _cycleStartTime < _cycleTime) return;
+    // ... otherwise start processing the first node in the list
+  DIAG(F("CMRInode: 138  _nodeListEnd:%d "),  _nodeListEnd);    
+  DIAG(F("CMRInode: 139  _currentNode:%d "),  _currentNode);        
+    _currentNode = _nodeListStart;
+  DIAG(F("CMRInode: 141  _currentNode:%d "),  _currentNode);    
+    _transmitState = TD_INIT;
+    _cycleStartTime = _currentMicros;
+  }
+  if (_currentNode == NULL) return;
+  switch (_transmitState) {
+    case TD_IDLE:
+    case TD_INIT:
+      enableTransmitter();
+      if (!_currentNode->isInitialised()) {
+        charsSent = sendInitialisation(_currentNode);
+        _currentNode->setInitialised();
+  DIAG(F("CMRInode: 153  _currentNode:%d "),  _currentNode);         
+        _transmitState = TD_TRANSMIT;
+        delayUntil(_currentMicros+_byteTransmitTime*charsSent);
+        break;
+      }
+      /* fallthrough */
+    case TD_TRANSMIT:
+      charsSent = sendData(_currentNode);
+      _transmitState = TD_PROMPT;
+      // Defer next entry for as long as it takes to transmit the characters, 
+      // to allow output queue to empty.  Allow 2 bytes extra.
+      delayUntil(_currentMicros+_byteTransmitTime*(charsSent+2));
+      break;
+    case TD_PROMPT:
+      charsSent = requestData(_currentNode);
+      disableTransmitter();
+      _transmitState = TD_RECEIVE;
+      _timeoutStart = _currentMicros; // Start timeout on response
+      break;
+    case TD_RECEIVE: // Waiting for response / timeout
+      if (_currentMicros - _timeoutStart > _timeoutPeriod) { 
+        // End of time slot allocated for responses.
+        _transmitState = TD_IDLE;
+        // Reset state of receiver
+        _receiveState = RD_SYN1;
+        // Move to next node
+     DIAG(F("CMRInode: 179  node:%d "),  _currentNode);
+        _currentNode = _currentNode->getNext();
+     DIAG(F("CMRInode: 181  node:%d "),  _currentNode);
+      }
+      break;
+  }
+}
+
+// Process any data bytes received from a CMRInode.
+void CMRIbus::processIncoming() {
+  int data = _serial->read();
+  if (data < 0) return;     // No characters to read
+
+    DIAG(F("CMRInode: 192  node:%d "),  _currentNode);
+  if (_transmitState != TD_RECEIVE || !_currentNode) return;   // Not waiting for input, so ignore.
+
+  uint8_t nextState = RD_SYN1;  // default to resetting state machine
+  switch(_receiveState) {
+    case RD_SYN1: 
+      if (data == SYN) nextState = RD_SYN2; 
+      break;
+    case RD_SYN2:
+      if (data == SYN) nextState = RD_STX; else nextState = RD_SYN2;
+      break;
+    case RD_STX:
+      if (data == STX) nextState = RD_ADDR;
+      break;
+    case RD_ADDR:
+      // If nodeID doesn't match, then ignore everything until next SYN-SYN-STX.
+      if (data == _currentNode->getNodeID() + 65) nextState = RD_TYPE;
+      break;
+    case RD_TYPE:
+      _receiveDataIndex = 0;  // Initialise data pointer
+      if (data == 'R') nextState = RD_DATA;
+      break;
+    case RD_DATA: // data body
+      if (data == DLE) // escape next character
+        nextState = RD_ESCDATA;
+      else if (data == ETX) { // end of data
+        // End of data message.  Protocol has all data in one
+        // message, so we don't need to wait any more.  Allow
+        // transmitter to proceed with next node in list.
+    DIAG(F("CMRInode: 221  node:%d "),  _currentNode);        
+        _currentNode = _currentNode->getNext();
+    DIAG(F("CMRInode: 223  node:%d "),  _currentNode);
+        _transmitState = TD_IDLE;
+      } else {
+        // Not end yet, so save data byte
+        _currentNode->saveIncomingData(_receiveDataIndex++, data);
+        nextState = RD_DATA; // wait for more data
+      }
+      break;
+    case RD_ESCDATA: // escaped data byte
+      _currentNode->saveIncomingData(_receiveDataIndex++, data);
+      nextState = RD_DATA;
+      break;
+  }
+  _receiveState = nextState;
+}
+
+// If configured for half duplex RS485, switch RS485 interface
+// into transmit mode.
+void CMRIbus::enableTransmitter() {
+  if (_transmitEnablePin != VPIN_NONE) 
+    ArduinoPins::fastWriteDigital(_transmitEnablePin, 1);
+  // If we need a delay before we start the packet header, 
+  // we can send a character or two to synchronise the 
+  // transmitter and receiver.
+  // SYN characters should be used, but a bug in the
+  // ArduinoCMRI library causes it to ignore the packet if
+  // it's preceded by an odd number of SYN characters.
+  // So send a SYN followed by a NUL in that case.
+  _serial->write(SYN);
+#if defined(ARDUINOCMRI_COMPATIBLE)
+  _serial->write(NUL);  // Reset the ArduinoCMRI library's parser
+#endif
+}
+
+// If configured for half duplex RS485, switch RS485 interface
+// into receive mode.
+void CMRIbus::disableTransmitter() {
+  // Wait until all data has been transmitted.  On the standard
+  // AVR driver, this waits until the FIFO is empty and all
+  // data has been sent over the link.
+  _serial->flush();
+  // If we don't trust the 'flush' function and think the 
+  // data's still in transit, then wait a bit longer.
+  if (_postDelay > 0)
+    delayMicroseconds(_postDelay);
+  // Hopefully, we can now safely switch off the transmitter.
+  if (_transmitEnablePin != VPIN_NONE) 
+    ArduinoPins::fastWriteDigital(_transmitEnablePin, 0);
+}    
+
+// Link to chain of CMRI bus instances
+CMRIbus *CMRIbus::_busList = NULL;
+
+
+/************************************************************
+ * CMRInode implementation
+ ************************************************************/
+
+// Constructor for CMRInode object
+CMRInode::CMRInode(VPIN firstVpin, int nPins, uint8_t busNo, uint8_t nodeID, char type, uint16_t inputs, uint16_t outputs) {
+  _firstVpin = firstVpin;
+  _nPins = nPins;
+  _busNo = busNo;
+  _nodeID = nodeID;
+  _type = type;
+
+  switch (_type) {
+    case 'M': // SMINI, fixed 24 inputs and 48 outputs
+      _numInputs = 24;
+      _numOutputs = 48;
+      break;
+    case 'C': // CPNODE with 16 to 144 inputs/outputs using 8-bit cards
+      _numInputs = inputs;
+      _numOutputs = outputs;
+      break;
+    case 'N': // Classic USIC and SUSIC using 24 bit i/o cards
+    case 'X': // SUSIC using 32 bit i/o cards
+    default:
+      DIAG(F("CMRInode: bus:%d nodeID:%d ERROR unsupported type %c"), _busNo, _nodeID, _type);
+      return; // Don't register device.
+  }
+  if ((unsigned int)_nPins < _numInputs + _numOutputs)
+    DIAG(F("CMRInode: bus:%d nodeID:%d WARNING number of Vpins does not cover all inputs and outputs"), _busNo, _nodeID);
+
+  // Allocate memory for states
+  _inputStates = (uint8_t *)calloc((_numInputs+7)/8, 1);
+  _outputStates = (uint8_t *)calloc((_numOutputs+7)/8, 1);
+  if (!_inputStates || !_outputStates) {
+    DIAG(F("CMRInode: ERROR insufficient memory"));
+    return;
+  }
+
+  // Add this device to HAL device list
+  IODevice::addDevice(this);
+
+  // Add CMRInode to CMRIbus object.
+  CMRIbus *bus = CMRIbus::findBus(_busNo);
+  if (bus != NULL) {
+    bus->addNode(this);
+    return;
+  }
+}

IO_CMRI.h

@@ -0,0 +1,292 @@
+/*
+ *  © 2023, 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/>.
+ */
+
+/*
+ * CMRIbus
+ * =======
+ * To define a CMRI bus, example syntax:
+ *    CMRIbus::create(bus, serial, baud[, cycletime[, pin]]);
+ * 
+ * bus = 0-255
+ * serial = serial port to be used (e.g. Serial3)
+ * baud = baud rate (9600, 19200, 28800, 57600 or 115200)
+ * cycletime = minimum time between successive updates/reads of a node in millisecs (default 500ms)
+ * pin = pin number connected to RS485 module's DE and !RE terminals for half-duplex operation (default VPIN_NONE)
+ * 
+ * Each bus must use a different serial port.
+ * 
+ * IMPORTANT: If you are using ArduinoCMRI library code by Michael Adams, at the time of writing this library
+ * is not compliant with the LCS-9.10.1 specification for CMRInet protocol.  
+ * Various work-arounds may be enabled within the driver by adding the following line to your config.h file,
+ * to allow nodes running the ArduinoCMRI library to communicate:
+ * 
+ *  #define ARDUINOCMRI_COMPATIBLE
+ * 
+ * CMRINode
+ * ========
+ * To define a CMRI node and associate it with a CMRI bus,
+ *    CMRInode::create(firstVPIN, numVPINs, bus, nodeID, type [, inputs, outputs]);
+ * 
+ * firstVPIN = first vpin in block allocated to this device
+ * numVPINs = number of vpins (e.g. 72 for an SMINI node)
+ * bus = 0-255
+ * nodeID = 0-127
+ * type = 'M' for SMINI (fixed 24 inputs and 48 outputs)
+ *        'C' for CPNODE (16 to 144 inputs/outputs in groups of 8)
+ *        (other types are not supported at this time).
+ * inputs = number of inputs (CPNODE only)
+ * outputs = number of outputs (CPNODE only)
+ * 
+ * Reference: "LCS-9.10.1
+ *             Layout Control Specification: CMRInet Protocol
+ *             Version 1.1 December 2014."
+ */
+
+#ifndef IO_CMRI_H
+#define IO_CMRI_H
+
+#include "IODevice.h"
+
+/**********************************************************************
+ * CMRInode class
+ * 
+ * This encapsulates the state associated with a single CMRI node, 
+ * which includes the nodeID type, number of inputs and outputs, and
+ * the states of the inputs and outputs.
+ **********************************************************************/
+class CMRInode : public IODevice {
+private:
+  uint8_t _busNo;
+  uint8_t _nodeID;
+  char _type;
+  CMRInode *_next = NULL;
+  uint8_t *_inputStates = NULL;
+  uint8_t *_outputStates = NULL;
+  uint16_t _numInputs = 0;
+  uint16_t _numOutputs = 0;
+  bool _initialised = false;
+
+public:
+  static void create(VPIN firstVpin, int nPins, uint8_t busNo, uint8_t nodeID, char type, uint16_t inputs=0, uint16_t outputs=0) {
+    if (checkNoOverlap(firstVpin, nPins)) new CMRInode(firstVpin, nPins, busNo, nodeID, type, inputs, outputs);
+  }
+  CMRInode(VPIN firstVpin, int nPins, uint8_t busNo, uint8_t nodeID, char type, uint16_t inputs=0, uint16_t outputs=0);
+
+  uint8_t getNodeID() {
+    return _nodeID;
+  }
+  CMRInode *getNext() {
+    return _next;
+  }
+  void setNext(CMRInode *node) {
+    _next = node;
+  }
+  bool isInitialised() {
+    return _initialised;
+  }
+  void setInitialised() {
+    _initialised = true;
+  }
+
+  void _begin() {
+    _initialised = false;
+  }
+
+  int _read(VPIN vpin) {
+    // Return current state from this device
+    uint16_t pin = vpin - _firstVpin;
+    if (pin < _numInputs) {
+      uint8_t mask = 1 << (pin & 0x7);
+      int index = pin / 8;
+      return (_inputStates[index] & mask) != 0;
+    } else
+      return 0;
+  }
+
+  void _write(VPIN vpin, int value) {
+    // Update current state for this device, in preparation the bus transmission
+    uint16_t pin = vpin - _firstVpin - _numInputs;
+    if (pin < _numOutputs) {
+      uint8_t mask = 1 << (pin & 0x7);
+      int index = pin / 8;
+      if (value)
+        _outputStates[index] |= mask;
+      else
+        _outputStates[index] &= ~mask;
+    }
+  }
+
+  void saveIncomingData(uint8_t index, uint8_t data) {
+    if (index < (_numInputs+7)/8)
+      _inputStates[index] = data;
+  }
+
+  uint8_t getOutputStates(uint8_t index) {
+    if (index < (_numOutputs+7)/8)
+      return _outputStates[index];
+    else
+      return 0;
+  }
+
+  uint16_t getNumInputs() {
+    return _numInputs;
+  }
+
+  uint16_t getNumOutputs() {
+    return _numOutputs;
+  }
+
+  char getType() {
+    return _type; 
+  }
+
+  uint8_t getBusNumber() {
+    return _busNo;
+  }
+
+  void _display() override {
+    DIAG(F("CMRInode type:'%c' configured on bus:%d nodeID:%d VPINs:%u-%u (in) %u-%u (out)"),
+      _type, _busNo, _nodeID, _firstVpin, _firstVpin+_numInputs-1,
+      _firstVpin+_numInputs, _firstVpin+_numInputs+_numOutputs-1);
+  }
+
+};
+
+/**********************************************************************
+ * CMRIbus class
+ * 
+ * This encapsulates the properties state of the bus and the
+ * transmission and reception of data across that bus.  Each CMRIbus
+ * object owns a set of CMRInode objects which represent the nodes
+ * attached to that bus.
+ **********************************************************************/
+class CMRIbus : public IODevice {
+private:
+  // Here we define the device-specific variables.  
+  uint8_t _busNo;
+  HardwareSerial *_serial;
+  unsigned long _baud;
+  VPIN _transmitEnablePin = VPIN_NONE;
+  CMRInode *_nodeListStart = NULL, *_nodeListEnd = NULL;
+  CMRInode *_currentNode = NULL;
+
+  // Transmitter state machine states
+  enum {TD_IDLE, TD_PRETRANSMIT, TD_INIT, TD_TRANSMIT, TD_PROMPT, TD_RECEIVE};
+  uint8_t _transmitState = TD_IDLE;
+  // Receiver state machine states.
+  enum {RD_SYN1, RD_SYN2, RD_STX, RD_ADDR, RD_TYPE, 
+      RD_DATA, RD_ESCDATA, RD_SKIPDATA, RD_SKIPESCDATA, RD_ETX};
+  uint8_t _receiveState = RD_SYN1;
+  uint16_t _receiveDataIndex = 0;  // Index of next data byte to be received.
+  CMRIbus *_nextBus = NULL;  // Pointer to next bus instance in list.
+  unsigned long _cycleStartTime = 0;
+  unsigned long _timeoutStart = 0;
+  unsigned long _cycleTime; // target time between successive read/write cycles, microseconds
+  unsigned long _timeoutPeriod; // timeout on read responses, in microseconds.
+  unsigned long _currentMicros;  // last value of micros() from _loop function.
+  unsigned long _postDelay; // delay time after transmission before switching off transmitter (in us)
+  unsigned long _byteTransmitTime; // time in us for transmission of one byte
+
+  static CMRIbus *_busList; // linked list of defined bus instances
+
+  // Definition of special characters in CMRInet protocol
+  enum : uint8_t {
+    NUL = 0x00,
+    STX = 0x02,
+    ETX = 0x03,
+    DLE = 0x10,
+    SYN = 0xff,
+  };
+
+public:
+  static void create(uint8_t busNo, HardwareSerial &serial, unsigned long baud, uint16_t cycleTimeMS=500, VPIN transmitEnablePin=VPIN_NONE) {
+    new CMRIbus(busNo, serial, baud, cycleTimeMS, transmitEnablePin);
+  } 
+
+  // Device-specific initialisation
+  void _begin() override {
+    // CMRInet spec states one stop bit, JMRI and ArduinoCMRI use two stop bits
+#if defined(ARDUINOCMRI_COMPATIBLE)
+    _serial->begin(_baud, SERIAL_8N2);
+#else
+    _serial->begin(_baud, SERIAL_8N1);
+#endif
+  #if defined(DIAG_IO)
+    _display();
+  #endif
+  }
+
+  // Loop function (overriding IODevice::_loop(unsigned long))
+  void _loop(unsigned long currentMicros) override;
+
+  // Display information about the device
+  void _display() override {
+    DIAG(F("CMRIbus %d configured, speed=%d baud, cycle=%d ms"), _busNo, _baud, _cycleTime/1000);
+  }
+
+  // Locate CMRInode object with specified nodeID.
+  CMRInode *findNode(uint8_t nodeID) {
+    for (CMRInode *node = _nodeListStart; node != NULL; node = node->getNext()) {
+      if (node->getNodeID() == nodeID) 
+        return node;
+    }
+    return NULL;
+  }
+
+  // Add new CMRInode to the list of nodes for this bus.
+  void addNode(CMRInode *newNode) {
+    if (!_nodeListStart)
+      _nodeListStart = newNode;
+    if (!_nodeListEnd) 
+      _nodeListEnd = newNode;
+    else
+      _nodeListEnd->setNext(newNode);
+  DIAG(F("bus: 260h nodeID: _nodeListStart:%d _nodeListEnd:%d"), _nodeListStart, _nodeListEnd);
+  }
+
+protected:
+  CMRIbus(uint8_t busNo, HardwareSerial &serial, unsigned long baud, uint16_t cycleTimeMS, VPIN transmitEnablePin);
+  uint16_t sendData(CMRInode *node);
+  uint16_t requestData(CMRInode *node);
+  uint16_t sendInitialisation(CMRInode *node);
+
+  // Process any data bytes received from a CMRInode.
+  void processIncoming();
+  // Process any outgoing traffic that is due.
+  void processOutgoing();
+  // Enable transmitter
+  void enableTransmitter();
+  // Disable transmitter and enable receiver
+  void disableTransmitter();
+
+
+public:
+  uint8_t getBusNumber() {
+    return _busNo;
+  }
+
+  static CMRIbus *findBus(uint8_t busNo) {
+    for (CMRIbus *bus=_busList; bus!=NULL; bus=bus->_nextBus) {
+      if (bus->_busNo == busNo) return bus;
+    }
+    return NULL;
+  }
+};
+
+#endif // IO_CMRI_H