class EBB(object):
"""Talk to the EiBotBoard"""
def __init__(self, port="/dev/ttyACM0", storedir=DEFAULT_STORE):
self.serial = serial.Serial(port, 9600, parity='N', rtscts=False, xonxoff=False, timeout=2)
self.newline_str = '\r\n'
self.storedir = storedir
self.max_resends = 1
self.maxmotors = 2
if not os.path.isdir(storedir):
os.mkdir(storedir)
self.persistent_state = PersistentDict(os.path.join(self.storedir, "EBBMotorState.json"), format="json")
# initialize motor states if they are not there already
self.persistent_state.setdefault("1", DEFAULT_MOTOR_CONFIG)
self.persistent_state.setdefault("2", DEFAULT_MOTOR_CONFIG)
self.persistent_state.setdefault("microsteps", 16) # must use the same value for both motors
self.persistent_state.sync()
self.pushEnabledState()
def readline(self):
# with this board, always seems to be 2 delimiters but the order varies.
line = ''
reply = ''
delim_count=0
while delim_count < 2:
reply = self.serial.read(1)
if reply == '\r' or reply == '\n':
delim_count += 1
line += reply
return line
def sendCMD(self, text_cmd = '', resend_number=0):
self.serial.flushInput() # get rid of lingering replies before new command
if DEBUG: print 'writing command: ' + text_cmd
self.serial.write(text_cmd + self.newline_str)
if DEBUG: print 'flushing...'
self.serial.flush()
if DEBUG: print 'reading reply...'
#reply = self.serial.readline(eol='\r')
reply = self.readline()
if DEBUG: print 'reply = ' + str(reply)
self.reply = reply
self.serial.flush()
return reply.rstrip()
def GetCurrent(self):
""" get the output current to the motor
(changed by pot on EBB surface) """
result = self.sendCMD("QC")
currint, V0 = result.split(',')
curr = float(currint) / 1023.0 * EBB_MAX_CURRENT
return curr
################### MOTOR FUNCTIONS #######################
def GetMotorPos(self, motornum):
state = self.persistent_state[str(motornum)]
return state["position"]
def SetMotorPos(self, motornum, position):
self.persistent_state[str(motornum)]["stepzero_position"] = position
self.persistent_state[str(motornum)]["position"] = position
self.persistent_state[str(motornum)]["steps"] = 0
self.persistent_state.sync()
return 0
def EnableMotor(self, motornum):
# this is done by the board with every move command;
# the command would be "EM,<enable 1>,<enable 2>\r\n"
self.persistent_state[str(motornum)]["enabled"] = True
self.persistent_state.sync()
self.pushEnabledState()
return 1
def GetEnabled(self, motornum):
return self.persistent_state[str(motornum)]["enabled"]
def DisableMotor(self, motornum):
self.persistent_state[str(motornum)]["enabled"] = False
self.persistent_state.sync()
self.pushEnabledState()
return 0
def pushEnabledState(self):
microsteps = self.persistent_state["microsteps"]
if not (microsteps in MICROSTEPS_CODES):
error_msg = "error: inconsistent microsteps number %d\n" % (microsteps,)
error_msg += "\nAllowed values: %s" % (str(MICROSTEPS_CODES.keys()))
print(error_msg)
return
enableCode = MICROSTEPS_CODES[microsteps]
m1en = enableCode if self.persistent_state["1"]["enabled"] else 0
m2en = enableCode if self.persistent_state["2"]["enabled"] else 0
self.sendCMD("EM,%d,%d" % (m1en, m2en))
def MoveMotor(self, motornum, position):
state = self.persistent_state[str(motornum)]
microsteps = int(self.persistent_state["microsteps"])
spd = float(state["stepsPerDegree"])
szero = float(state["stepzero_position"])
steps = int(state["steps"])
speed = float(state["speed"])
old_pos = (float(steps) / spd) + szero
posdelta = float(position - old_pos)
pdelta = int(posdelta * spd * microsteps/16)
new_steps = steps + int(pdelta * 16/microsteps)
tdelta = int(abs(posdelta / speed * 1000.0)) # milliseconds
axes = {"1": 0, "2": 0} # motor move distance
axes[str(motornum)] = pdelta
if pdelta == 0:
print("already there.")
return
if self.CheckAnyMoving():
print("error: already moving")
return
self.sendCMD("SM,%d,%d,%d" % (tdelta, axes["1"], axes["2"]))
self.persistent_state[str(motornum)]["steps"] = new_steps
actual_pos = (float(new_steps) / spd) + szero
self.persistent_state[str(motornum)]["position"] = actual_pos
self.persistent_state["1"]["enabled"] = True
self.persistent_state["2"]["enabled"] = True
self.persistent_state.sync()
def StopMotor(self, motornum):
#print("stopping...")
self.sendCMD('ES')
#self.sendCMD('EM,0,0')
#self.pushEnabledState()
#print "not implemented: no stopping with EBB!"
return 0
def CheckHardwareLimits(self, motornum):
return False
def CheckAnyMoving(self):
reply = self.sendCMD('QM')
moving = reply.split(',')[1].strip() == '1'
return moving
def CheckMoving(self, motornum):
reply = self.sendCMD('QM')
moving = reply.split(',')[motornum+1].strip() == '1'
return moving
