def check_initialised(self):
command = AlpesCommand(PREFIXES.LECTURE_REGISTRE,
REGISTRE_INITIALISATION, 1)
self.serial.write(command.pack())
response = AlpesResponse(
self.serial.read(command.expected_response_size))
return response.data[0] == 1
def left_or_right(self):
command = AlpesCommand(PREFIXES.LECTURE_REGISTRE,
1000 + REGISTRES.ID_DROITE_GAUCHE, 1)
self.serial.write(command.pack())
response = AlpesResponse(
self.serial.read(command.expected_response_size))
self.id = 'left' if response.data[0] == 2 else 'right'
return self.id
def __read_registers_consecutively(self, first_register_position,
number_of_registers):
command = AlpesCommand(PREFIXES.LECTURE_REGISTRE,
first_register_position, number_of_registers,
[])
self.serial.write(command.pack())
return AlpesResponse(self.serial.read(
command.expected_response_size)).data
def read_velocities(self): #, get_directions = 'False'):
# Asks the hand and returns angular velocity of the motors in turns/min
command = AlpesCommand(PREFIXES.LECTURE_VITESSE_MOTEUR, 0, 6,
self.current_limit)
self.serial.write(command.pack())
response = AlpesResponse(
self.serial.read(command.expected_response_size)).data
return [d / 100 for d in response] # Conversion to turns/min
def read_positions(self):
command = AlpesCommand(PREFIXES.LECTURE_POSITION_CODEUR, 0, 6,
self.current_limit)
self.serial.write(command.pack())
response = AlpesResponse(
self.serial.read(command.expected_response_size))
# Sometimes when rotating backwards, motors go slightly beyond the origin point of rotation,
# which results in values like 65535 that are, in fact, impossible.
# In my opinion, it only clutters the user's data and therefore I filter it out.
result = list(map(lambda x: x if x < 65500 else 0, response.data))
limits = [21000, 19000, 43000, 43000, 43000, 43000]
result = list(map(lambda x, y: x if x < y else y, result, limits))
return result
def __write_registers_consecutively(self, first_register_position,
number_of_registers, data):
if not isinstance(data, list):
raise ValueError(
'Provided data should be a list, even in single value')
if len(data) != number_of_registers:
raise ValueError(
'Number of registers requested for writing does not match the length of provided data'
)
command = AlpesCommand(PREFIXES.ECRITURE_REGISTRE,
first_register_position, number_of_registers,
data)
self.serial.write(command.pack())
return AlpesResponse(self.serial.read(command.expected_response_size))
def read_velocities_and_directions(self):
# Asks the hand and returns angular velocity of the motors in turns/min
# ATTENTION: this method is left here in case someone wants to re-test it.
# Previous attempts to receive the direction of rotation from the hand were not successful: contents of DIR_MOTEUR_CODEUR do not change in function of direction.
command = AlpesCommand(PREFIXES.LECTURE_VITESSE_MOTEUR, 0, 6,
self.current_limit)
self.serial.write(command.pack())
response = AlpesResponse(
self.serial.read(command.expected_response_size)).data
# Getting sign of velocity is optional since it requires additional reading procedure
# and may slow down the acquisition. In most of the cases, sign can be derived from the command.
directions = self.read_registers_across(REGISTRES.DIR_MOTEUR_CODEUR)
#print('AlpesHand.read_velocities_and_directions:', directions)
signs = [(d & 2) > 0
for d in directions] # Read second bit of the response
for i in range(len(response)):
if not signs[i]:
response[i] *= -1
return response