Added sentrybot control test.

sentrybot.py

@@ -0,0 +1,159 @@
+#SentryBot control prototype.
+
+#todo: Rotate head to max range
+#  if head hits torso turn range, rotate torso
+#  Do same for tilt.
+
+#todo: May need to smooth out input.  Simple way is to average n values (3?)
+
+#todo: May need to ease in/out of movement in addition to time scaling.
+
+import pyb
+from pca9865 import pca9865
+import joystick
+
+def moveto( aSource, aTarget, aRate ) :
+  '''Move from aSource to aTarget by given rate.'''
+  if aTarget < 0 :
+    aSource = aTarget
+  else:
+    diff = (aTarget - aSource) * aRate
+    aSource += diff
+    if diff < 0 :
+      aSource = max(aSource, aTarget)
+    else:
+      aSource = min(aSource, aTarget)
+
+  return aSource
+
+def clamp( aValue, aRange ) :
+  '''Clamp value between +/- aRange.'''
+  s = -1.0 if aValue < 0.0 else 1.0
+  aValue = min(abs(aValue), aRange)
+  return aValue * s
+
+def smooth( aValue ) :
+  '''If value isn't above a certain threshold just return 0.0'''
+  return aValue if abs(aValue) > 0.2 else 0.0
+
+class bot(pca9865) :
+  _HEAD_TURN_RANGE = 45.0
+  _HEAD_TILT_RANGE = 20.0
+  _HEAD_TILT_CENTER = -90.0 + _HEAD_TILT_RANGE
+  _TORSO_TURN_START = 30.0
+  _TORSO_TURN_RANGE = 85.0
+  _TORSO_TILT_START = 10.0
+  _TORSO_TILT_RANGE = 10.0
+  _TORSO_TILT_CENTER = -90.0 + _TORSO_TILT_RANGE
+  _WHEEL_TURN_START = 80.0
+
+  #Center value % for wheels.
+  _LEFT_WHEEL_CENTER = -9.0 #45.0% = 81.0 deg or -9.0 if +/- 90.0
+  _RIGHT_WHEEL_CENTER = -4.0 #48.0% = 86.4 deg or -4.0 if +/- 90.0
+
+  _pcaloc = const(2)
+
+  #Servo indexes.
+  _ttwist = const(0)
+  _ttilt = const(1)
+  _htwist = const(2)
+  _htilt = const(3)
+  _lwheel = const(4)
+  _rwheel = const(5)
+
+  _updatefreq = const(16) #ms = 60hz.
+
+  #torso twist, tilt, head twist, tilt, l wheel, r wheel.
+  _servopinA = [12, 13, 14, 15, 8, 9]
+  #turn rate in degrees/second.
+  _servorateA = [66.0, -33.0, 66.0, -33.0, 11.0, 11.0]
+  _servocenterA = [0.0, _TORSO_TILT_CENTER, 0.0, _HEAD_TILT_CENTER, _LEFT_WHEEL_CENTER, _RIGHT_WHEEL_CENTER]
+
+  def __init__( self ) :
+    super().__init__(_pcaloc)  #init PCA 9865
+    self._joystick = joystick.joystick(pyb.Pin.board.Y11, pyb.Pin.board.Y12, pyb.Pin.board.X8)
+    #Values +/-90 deg.  -100 = off.
+    self._servoA = [0.0, -bot._TORSO_TILT_RANGE, 0.0, 0.0, 0.0, 0.0]
+    self._time = pyb.millis()
+    self.updateservos()
+
+  def updateservos( self ) :
+    '''Iterate through all servo angles and write to servo.'''
+    for i, s in enumerate(self._servoA) :
+      a = bot._servocenterA[i] + s
+      self.setangle(bot._servopinA[i], a)
+
+  def updatehead( self, aDT ) :
+    '''Update movement from joystick.  aDT is seconds passed since last update.'''
+    x = self._joystick.x
+    y = self._joystick.y
+
+    #Get turn/tilt rate for head.
+    turn = x * bot._servorateA[_htwist] * aDT
+    tilt = y * bot._servorateA[_htilt] * aDT
+
+    #Move turn/tilt by the desired rate from the joystick input.
+    h = clamp(self._servoA[_htwist] + turn, bot._HEAD_TURN_RANGE)
+    self._servoA[_htwist] = h
+    self._servoA[_htilt] = clamp(self._servoA[_htilt] + tilt, bot._HEAD_TILT_RANGE)
+
+    #Now get the turn rate for torso.
+    turn = x * bot._servorateA[_ttwist] * aDT
+
+    th = self._servoA[_ttwist]
+
+    #If head turn is > torso turn start angle and moving in the right direction then update torso turn.
+    if abs(h) >= bot._TORSO_TURN_START and h * turn > 0 :
+      th = clamp(th + turn, bot._TORSO_TURN_RANGE)
+      self._servoA[_ttwist] = th
+
+    lw = -1000.0
+    rw = -1000.0
+
+    if abs(th) >= bot._WHEEL_TURN_START and th * turn > 0 :
+      lw = bot._servorateA[_lwheel]
+      if th < 0 :
+        lw = -lw
+
+      rw = lw
+
+    self._servoA[_lwheel] = lw
+    self._servoA[_rwheel] = rw
+
+  def updatetime( self ) :
+    '''Update the time, then return delta time in seconds.'''
+    delay = 1
+
+    #Loop until we hit or exceed the target frame rate.
+    while delay > 0 :
+      ms = pyb.millis()
+      dt = ms - self._time
+      delay = _updatefreq - dt
+
+      #If we need to wait longer then do so.
+      if delay > 0 :
+        pyb.delay(delay)
+
+    self._time = ms
+    return dt / 1000.0  #Convert ms to seconds.
+
+  def update( self ) :
+    dt = self.updatetime()
+
+    #Read input and convert to rotations.
+    self._joystick.update()
+
+    #todo: Move wheels based on what input?
+
+    #Apply rotations to head and torso.
+    self.updatehead(dt)
+    #Write values to the servos.
+    self.updateservos()
+
+def run(  ) :
+  b = bot()
+  while True :
+    b.update()
+
+
+