Start adding servo to EX-IO

IO_EXIOExpander.h

@@ -49,6 +49,17 @@
  */
 class EXIOExpander : public IODevice {
 public:
+
+  enum ProfileType : uint8_t {
+    Instant = 0,  // Moves immediately between positions (if duration not specified)
+    UseDuration = 0, // Use specified duration
+    Fast = 1,     // Takes around 500ms end-to-end
+    Medium = 2,   // 1 second end-to-end
+    Slow = 3,     // 2 seconds end-to-end
+    Bounce = 4,   // For semaphores/turnouts with a bit of bounce!!
+    NoPowerOff = 0x80, // Flag to be ORed in to suppress power off after move.
+  };
+
   static void create(VPIN vpin, int nPins, uint8_t i2cAddress) {
     if (checkNoOverlap(vpin, nPins, i2cAddress)) new EXIOExpander(vpin, nPins, i2cAddress);
   }
@@ -59,6 +70,11 @@ private:
     _firstVpin = firstVpin;
     _nPins = nPins;
     _i2cAddress = i2cAddress;
+    // To save RAM, space for servo configuration is not allocated unless a pin is used.
+    // Initialise the pointers to NULL.
+    for (int i=0; i<_nPins; i++) {
+      _servoData[i] = NULL;
+    }
     addDevice(this);
   }
 
@@ -121,6 +137,28 @@ private:
         DIAG(F("Vpin %d cannot be used as a digital input pin"), (int)vpin);
         return false;
       }
+    } else if (configType == CONFIGURE_SERVO) {
+      if (paramCount != 5) return false;
+#ifdef DIAG_IO
+      DIAG(F("Servo: Configure VPIN:%d Apos:%d Ipos:%d Profile:%d Duration:%d state:%d"), 
+        vpin, params[0], params[1], params[2], params[3], params[4]);
+#endif
+      struct ServoData *s = _servoData[pin];
+      if (s == NULL) { 
+        _servoData[pin] = (struct ServoData *)calloc(1, sizeof(struct ServoData));
+        s = _servoData[pin];
+        if (!s) return false; // Check for failed memory allocation
+      }
+      s->activePosition = params[0];
+      s->inactivePosition = params[1];
+      s->profile = params[2];
+      s->duration = params[3];
+      int state = params[4];
+      if (state != -1) {
+        // Position servo to initial state
+        IODevice::writeAnalogue(pin, state ? s->activePosition : s->inactivePosition, 0, 0);
+      } 
+      return true;
     } else {
       return false;
     }
@@ -182,13 +220,86 @@ private:
     }
   }
 
-  void _writeAnalogue(VPIN vpin, int value, uint8_t param1, uint16_t param2) override {
+  // void _writeAnalogue(VPIN vpin, int value, uint8_t param1, uint16_t param2) override {
+  void _writeAnalogue(VPIN vpin, int value, uint8_t profile, uint16_t duration) override {
     int pin = vpin - _firstVpin;
+    /* Initial _writeAnalogue here
     _command4Buffer[0] = EXIOWRAN;
     _command4Buffer[1] = pin;
     _command4Buffer[2] = value & 0xFF;
     _command4Buffer[3] = value >> 8;
     I2CManager.write(_i2cAddress, _command4Buffer, 4);
+    */
+    #ifdef DIAG_IO
+    DIAG(F("Servo: WriteAnalogue Vpin:%d Value:%d Profile:%d Duration:%d %S"), 
+      vpin, value, profile, duration, _deviceState == DEVSTATE_FAILED?F("DEVSTATE_FAILED"):F(""));
+    #endif
+    if (_deviceState == DEVSTATE_FAILED) return;
+    int pin = vpin - _firstVpin;
+    if (value > 4095) value = 4095;
+    else if (value < 0) value = 0;
+
+    struct ServoData *s = _servoData[pin];
+    if (s == NULL) {
+      // Servo pin not configured, so configure now using defaults
+      s = _servoData[pin] = (struct ServoData *) calloc(sizeof(struct ServoData), 1);
+      if (s == NULL) return;  // Check for memory allocation failure
+      s->activePosition = 4095;
+      s->inactivePosition = 0;
+      s->currentPosition = value;
+      s->profile = Instant | NoPowerOff;  // Use instant profile (but not this time)
+    }
+
+    // Animated profile.  Initiate the appropriate action.
+    s->currentProfile = profile;
+    uint8_t profileValue = profile & ~NoPowerOff;  // Mask off 'don't-power-off' bit.
+    s->numSteps = profileValue==Fast ? 10 :   // 0.5 seconds
+                  profileValue==Medium ? 20 : // 1.0 seconds
+                  profileValue==Slow ? 40 :   // 2.0 seconds
+                  profileValue==Bounce ? sizeof(_bounceProfile)-1 : // ~ 1.5 seconds
+                  duration * 2 + 1; // Convert from deciseconds (100ms) to refresh cycles (50ms)
+    s->stepNumber = 0;
+    s->toPosition = value;
+    s->fromPosition = s->currentPosition;
+  }
+
+  void updatePosition(uint8_t pin) {
+    struct ServoData *s = _servoData[pin];
+    if (s == NULL) return; // No pin configuration/state data
+
+    if (s->numSteps == 0) return; // No animation in progress
+
+    if (s->stepNumber == 0 && s->fromPosition == s->toPosition) {
+      // Go straight to end of sequence, output final position.
+      s->stepNumber = s->numSteps-1;
+    }
+
+    if (s->stepNumber < s->numSteps) {
+      // Animation in progress, reposition servo
+      s->stepNumber++;
+      if ((s->currentProfile & ~NoPowerOff) == Bounce) {
+        // Retrieve step positions from array in flash
+        uint8_t profileValue = GETFLASH(&_bounceProfile[s->stepNumber]);
+        s->currentPosition = map(profileValue, 0, 100, s->fromPosition, s->toPosition);
+      } else {
+        // All other profiles - calculate step by linear interpolation between from and to positions.
+        s->currentPosition = map(s->stepNumber, 0, s->numSteps, s->fromPosition, s->toPosition);
+      }
+      // Send servo command
+      // _slaveDevice->writeAnalogue(_firstSlavePin+pin, s->currentPosition);
+    } else if (s->stepNumber < s->numSteps + _catchupSteps) {
+      // We've finished animation, wait a little to allow servo to catch up
+      s->stepNumber++;
+    } else if (s->stepNumber == s->numSteps + _catchupSteps 
+              && s->currentPosition != 0) {
+  #ifdef IO_SWITCH_OFF_SERVO
+      if ((s->currentProfile & NoPowerOff) == 0) {
+        // Wait has finished, so switch off PWM to prevent annoying servo buzz
+        // _slaveDevice->writeAnalogue(_firstSlavePin+pin, 0);
+      }
+  #endif
+      s->numSteps = 0;  // Done now.
+    }
   }
 
   void _display() override {
@@ -216,6 +327,35 @@ private:
   byte _receive3Buffer[3];
   uint8_t* _analoguePinMap;
 
+  // Servo specific
+  struct ServoData {
+    uint16_t activePosition : 12; // Config parameter
+    uint16_t inactivePosition : 12; // Config parameter
+    uint16_t currentPosition : 12;
+    uint16_t fromPosition : 12;
+    uint16_t toPosition : 12; 
+    uint8_t profile;  // Config parameter
+    uint16_t stepNumber; // Index of current step (starting from 0)
+    uint16_t numSteps;  // Number of steps in animation, or 0 if none in progress.
+    uint8_t currentProfile; // profile being used for current animation.
+    uint16_t duration; // time (tenths of a second) for animation to complete.
+  }; // 14 bytes per element, i.e. per pin in use
+  
+  struct ServoData *_servoData [16];
+
+  static const uint8_t _catchupSteps = 5; // number of steps to wait before switching servo off
+  static const uint8_t FLASH _bounceProfile[30];
+
+  const unsigned int refreshInterval = 50; // refresh every 50ms
+
+// Profile for a bouncing signal or turnout
+// The profile below is in the range 0-100% and should be combined with the desired limits
+// of the servo set by _activePosition and _inactivePosition.  The profile is symmetrical here,
+// i.e. the bounce is the same on the down action as on the up action.  First entry isn't used.
+const byte FLASH EXIOExpander::_bounceProfile[30] = 
+    {0,2,3,7,13,33,50,83,100,83,75,70,65,60,60,65,74,84,100,83,75,70,70,72,75,80,87,92,97,100};
+
+  // EX-IOExpander protocol flags
   enum {
     EXIOINIT = 0xE0,    // Flag to initialise setup procedure
     EXIORDY = 0xE1,     // Flag we have completed setup procedure, also for EX-IO to ACK setup