class PyMata:
"""
This class contains the complete set of API methods that permit control of an Arduino
Micro-Controller utilizing Firmata or its derivatives.
For information about the Firmata protocol, refer to: http://firmata.org/wiki/Protocol
"""
# some state variables
HIGH = 1 # digital pin state high value
LOW = 0 # digital pin state low value
REPORTING_ENABLE = 1 # enable reporting for REPORT_ANALOG or REPORT_DIGITAL message sent to firmata
REPORTING_DISABLE = 0 # disable reporting for REPORT_ANALOG or REPORT_DIGITAL message sent to firmata
# Shared Resources - data structures, controlling mechanisms, and reference variables
# Commands and data received from Firmata via the serial interface are placed into the command deque.
# The pymata_command_handler class removes and processes this information.
command_deque = deque()
# This is the instance reference to the communications port object
arduino = None
# This is a thread lock to assure data integrity when reading or writing to the data response tables
# (defined in the CommandHandler class). It shared by the pymata class and the pymata_command_handler class.
data_lock = threading.Lock()
# This is the instance reference to the _command_handler
_command_handler = None
# pin modes
INPUT = 0x00 # pin set as input
OUTPUT = 0x01 # pin set as output
ANALOG = 0x02 # analog pin in analogInput mode
PWM = 0x03 # digital pin in PWM output mode
SERVO = 0x04 # digital pin in Servo output mode
I2C = 0x06 # pin included in I2C setup
ONEWIRE = 0x07 # possible future feature
STEPPER = 0x08 # any pin in stepper mode
TONE = 0x09 # Any pin in TONE mode
ENCODER = 0x0a
SONAR = 0x0b # Any pin in SONAR mode
IGNORE = 0x7f
# the following pin modes are not part of or defined by Firmata
# but used by PyMata
DIGITAL = 0x20
# I2C command operation modes
I2C_WRITE = 0B00000000
I2C_READ = 0B00001000
I2C_READ_CONTINUOUSLY = 0B00010000
I2C_STOP_READING = 0B00011000
I2C_READ_WRITE_MODE_MASK = 0B00011000
# Tone commands
TONE_TONE = 0 # play a tone
TONE_NO_TONE = 1 # turn off tone
# Stepper Motor Sub-commands
STEPPER_CONFIGURE = 0 # configure a stepper motor for operation
STEPPER_STEP = 1 # command a motor to move at the provided speed
STEPPER_LIBRARY_VERSION = 2 # used to get stepper library version number
# each byte represents a digital port and its value contains the current port settings
digital_output_port_pins = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
#noinspection PyPep8Naming
def __init__(self, frame, port_id='/dev/ttyUSB0'):
"""
The "constructor" instantiates the entire interface. It starts the operational threads for the serial
interface as well as for the command handler.
@param port_id: Communications port specifier (COM3, /dev/ttyACM0, etc)
"""
# Currently only serial communication over USB is supported, but in the future
# wifi and other transport mechanism support is anticipated
# reference pointer to the text area on the GUI
self.frame = frame
self.frame.show_msg(11)
frame.show_msg(12)
frame.text.see(END)
frame.update_idletasks()
# Instantiate the serial support class
self.transport = PyMataSerial(port_id, self.command_deque, frame)
# Attempt opening communications with the Arduino micro-controller
self.transport.open()
time.sleep(1)
# Start the data receive thread
self.transport.start()
# Instantiate the command handler
self._command_handler = PyMataCommandHandler(self, self.frame)
########################################################################
# constants defined locally from values contained in the command handler
########################################################################
# Data latch state constants to be used when accessing data returned from get_latch_data methods.
# The get_latch data methods return [pin_number, latch_state, latched_data, time_stamp]
# These three constants define possible values for the second item in the list, latch_state
# this pin will be ignored for latching - table initialized with this value
self.LATCH_IGNORE = self._command_handler.LATCH_IGNORE
# When the next pin value change is received for this pin, if it matches the latch criteria
# the data will be latched.
self.LATCH_ARMED = self._command_handler.LATCH_ARMED
# Data has been latched. Read the data to re-arm the latch.
self.LATCH_LATCHED = self._command_handler.LATCH_LATCHED
#
# These constants are used when setting a data latch.
# Latch threshold types
#
self.DIGITAL_LATCH_HIGH = self._command_handler.DIGITAL_LATCH_HIGH
self.DIGITAL_LATCH_LOW = self._command_handler.DIGITAL_LATCH_LOW
self.ANALOG_LATCH_GT = self._command_handler.ANALOG_LATCH_GT
self.ANALOG_LATCH_LT = self._command_handler.ANALOG_LATCH_LT
self.ANALOG_LATCH_GTE = self._command_handler.ANALOG_LATCH_GTE
self.ANALOG_LATCH_LTE = self._command_handler.ANALOG_LATCH_LTE
# constants to be used to parse the data returned from calling
# get_X_latch_data()
self.LATCH_PIN = 0
self.LATCH_STATE = 1
self.LATCHED_DATA = 2
self.LATCHED_TIME_STAMP = 3
# Start the command processing thread
self._command_handler.start()
# Command handler should now be prepared to receive replies from the Arduino, so go ahead
# detect the Arduino board
frame.show_msg(13)
frame.text.see(END)
frame.update_idletasks()
# perform board auto discovery
if not self._command_handler.auto_discover_board():
# board was not found so shutdown
frame.show_msg(17)
self._command_handler.stop()
self.transport.stop()
self._command_handler.join()
self.transport.join()
time.sleep(2)
def analog_mapping_query(self):
"""
Send an analog mapping query message via sysex. Client retrieves the results with a
call to get_analog_mapping_request_results()
"""
self._command_handler.send_sysex(self._command_handler.ANALOG_MAPPING_QUERY, None)
def analog_read(self, pin):
"""
Retrieve the last analog data value received for the specified pin.
@param pin: Selected pin
@return: The last value entered into the analog response table.
"""
with self.data_lock:
data = self._command_handler.analog_response_table[pin][self._command_handler.RESPONSE_TABLE_PIN_DATA_VALUE]
return data
def analog_write(self, pin, value):
"""
Set the specified pin to the specified value.
@param pin: Pin number
@param value: Pin value
@return: No return value
"""
if self._command_handler.ANALOG_MESSAGE + pin < 0xf0:
command = [self._command_handler.ANALOG_MESSAGE + pin, value & 0x7f, value >> 7]
self._command_handler.send_command(command)
else:
self.extended_analog(pin, value)
def capability_query(self):
"""
Send a Firmata capability query message via sysex. Client retrieves the results with a
call to get_capability_query_results()
The Arduino can be rather slow in responding to this command. For
the Mega 2560 R3 it has taken up to 25 seconds for a response.
"""
self._command_handler.send_sysex(self._command_handler.CAPABILITY_QUERY, None)
def close(self):
"""
This method will close the transport (serial port) and exit
@return: No return value, but sys.exit(0) is called.
"""
self.transport.close()
self.frame.show_msg(14)
self.frame.text.see(END)
self.frame.update_idletasks()
#sys.exit(0)
def digital_read(self, pin):
"""
Retrieve the last digital data value received for the specified pin.
NOTE: This command will return values for digital, pwm, etc, pin types
@param pin: Selected pin
@return: The last value entered into the digital response table.
"""
with self.data_lock:
data = \
self._command_handler.digital_response_table[pin][self._command_handler.RESPONSE_TABLE_PIN_DATA_VALUE]
return data
def digital_write(self, pin, value):
"""
Set the specified pin to the specified value.
@param pin: pin number
@param value: pin value
@return: No return value
"""
# The command value is not a fixed value, but needs to be calculated using the
# pin's port number
#
#
port = pin / 8
calculated_command = self._command_handler.DIGITAL_MESSAGE + port
mask = 1 << (pin % 8)
# Calculate the value for the pin's position in the port mask
if value == 1:
self.digital_output_port_pins[port] |= mask
else:
self.digital_output_port_pins[port] &= ~mask
# Assemble the command
command = (calculated_command, self.digital_output_port_pins[port] & 0x7f,
self.digital_output_port_pins[port] >> 7)
self._command_handler.send_command(command)
def disable_analog_reporting(self, pin):
"""
Disables analog reporting for a single analog pin.
@param pin: Analog pin number. For example for A0, the number is 0.
@return: No return value
"""
command = [self._command_handler.REPORT_ANALOG + pin, self.REPORTING_DISABLE]
self._command_handler.send_command(command)
def disable_digital_reporting(self, pin):
"""
Disables digital reporting. By turning reporting off for this pin, reporting
is disabled for all 8 bits in the "port" -
@param pin: Pin and all pins for this port
@return: No return value
"""
port = pin / 8
command = [self._command_handler.REPORT_DIGITAL + port, self.REPORTING_DISABLE]
self._command_handler.send_command(command)
def enable_analog_reporting(self, pin):
"""
Enables analog reporting. By turning reporting on for a single pin,
@param pin: Analog pin number. For example for A0, the number is 0.
@return: No return value
"""
command = [self._command_handler.REPORT_ANALOG + pin, self.REPORTING_ENABLE]
self._command_handler.send_command(command)
def enable_digital_reporting(self, pin):
"""
Enables digital reporting. By turning reporting on for all 8 bits in the "port" -
this is part of Firmata's protocol specification.
@param pin: Pin and all pins for this port
@return: No return value
"""
port = pin / 8
command = [self._command_handler.REPORT_DIGITAL + port, self.REPORTING_ENABLE]
self._command_handler.send_command(command)
def encoder_config(self, pin_a, pin_b):
"""
This command enables the rotary encoder (2 pin + ground) and will
enable encoder reporting.
NOTE: This command is not currently part of standard arduino firmata, but is provided for legacy
support of CodeShield on an Arduino UNO.
@param pin_a: Encoder pin 1.
@param pin_b: Encoder pin 2.
@return: No return value
"""
data = [pin_a, pin_b]
self._command_handler.digital_response_table[pin_a][self._command_handler.RESPONSE_TABLE_MODE] \
= self.ENCODER
self._command_handler.digital_response_table[pin_b][self._command_handler.RESPONSE_TABLE_MODE] \
= self.ENCODER
self._command_handler.send_sysex(self._command_handler.ENCODER_CONFIG, data)
def extended_analog(self, pin, data):
"""
This method will send an extended data analog output command to the selected pin
@param pin: 0 - 127
@param data: 0 - 0xfffff
"""
analog_data = [pin, data & 0x7f, (data >> 7) & 0x7f, data >> 14]
self._command_handler.send_sysex(self._command_handler.EXTENDED_ANALOG, analog_data)
def get_analog_latch_data(self, pin):
"""
A list is returned containing the latch state for the pin, the latched value, and the time stamp
[pin_num, latch_state, latched_value, time_stamp]
If the the latch state is LATCH_LATCHED, the table is reset (data and timestamp set to zero)
@param pin: Pin number.
@return: [pin, latch_state, latch_data_value, time_stamp]
"""
return self._command_handler.get_analog_latch_data(pin)
def get_analog_mapping_request_results(self):
"""
Call this method after calling analog_mapping_query() to retrieve its results
@return: raw data returned by firmata
"""
return self._command_handler.analog_mapping_query_results
def get_analog_response_table(self):
"""
This method returns a list of lists representing the current pin mode and
associated data values for all analog pins.
All configured pin types, both input and output will be listed. Output pin data will contain zero.
@return: The last update of the digital response table
"""
return self._command_handler.get_analog_response_table()
def get_capability_query_results(self):
"""
Retrieve the data returned by a previous call to capability_query()
@return: Raw capability data returned by firmata
"""
return self._command_handler.capability_query_results
def get_digital_latch_data(self, pin):
"""
A list is returned containing the latch state for the pin, the latched value, and the time stamp
[pin_num, latch_state, latched_value, time_stamp]
If the the latch state is LATCH_LATCHED, the table is reset (data and timestamp set to zero)
@param pin: Pin number.
@return: [pin, latch_state, latch_data_value, time_stamp]
"""
return self._command_handler.get_digital_latch_data(pin)
def get_digital_response_table(self):
"""
This method returns a list of lists representing the current pin mode
and associated data for all digital pins.
All pin types, both input and output will be listed. Output pin data will contain zero.
@return: The last update of the digital response table
"""
return self._command_handler.get_digital_response_table()
def get_firmata_version(self):
"""
Retrieve the firmata version information returned by a previous call to refresh_report_version()
@return: Firmata_version list [major, minor] or None
"""
return self._command_handler.firmata_version
def get_firmata_firmware_version(self):
"""
Retrieve the firmware id information returned by a previous call to refresh_report_firmware()
@return: Firmata_firmware list [major, minor, file_name] or None
"""
return self._command_handler.firmata_firmware
def get_pin_state_query_results(self):
"""
This method returns the results of a previous call to pin_state_query() and then resets
the pin state query data to None
@return: Raw pin state query data
"""
r_data = self._command_handler.last_pin_query_results
self._command_handler.last_pin_query_results = []
return r_data
#noinspection PyMethodMayBeStatic
def get_pymata_version(self):
"""
Returns the PyMata version number in a list: [Major Number, Minor Number]
@return:
"""
return [1, 57]
# noinspection PyMethodMayBeStatic
def get_sonar_data(self):
"""
Retrieve Ping (HC-SR04 type) data. The data is presented as a dictionary.
The 'key' is the trigger pin specified in sonar_config() and the 'data' is the
current measured distance (in centimeters)
for that pin. If there is no data, the value is set to IGNORE (127).
@return: active_sonar_map
"""
return self._command_handler.active_sonar_map
def get_stepper_version(self, timeout=20):
"""
@param timeout: specify a time to allow arduino to process and return a version
@return: the stepper version number if it was set.
"""
# get current time
start_time = time.time()
# wait for up to 20 seconds for a successful capability query to occur
while self._command_handler.stepper_library_version <= 0:
if time.time() - start_time > timeout:
self.frame.show_msg(16)
return
else:
pass
return self._command_handler.stepper_library_version
def i2c_config(self, read_delay_time=0, pin_type=None, clk_pin=0, data_pin=0):
"""
NOTE: THIS METHOD MUST BE CALLED BEFORE ANY I2C REQUEST IS MADE
This method initializes Firmata for I2c operations.
It allows setting of a read time delay amount, and to optionally track
the pins as I2C in the appropriate response table.
To track pins: Set the pin_type to ANALOG or DIGITAL and provide the pin numbers.
If using ANALOG, pin numbers use the analog number, for example A4: use 4.
@param read_delay_time: an optional parameter, default is 0
@param pin_type: ANALOG or DIGITAL to select response table type to track pin numbers
@param clk_pin: pin number (see comment above).
@param data_pin: pin number (see comment above).
@return: No Return Value
"""
data = [read_delay_time & 0x7f, read_delay_time >> 7]
self._command_handler.send_sysex(self._command_handler.I2C_CONFIG, data)
# If pin type is set, set pin mode in appropriate response table for these pins
if pin_type:
if pin_type == self.DIGITAL:
self._command_handler.digital_response_table[clk_pin][self._command_handler.RESPONSE_TABLE_MODE] \
= self.I2C
self._command_handler.digital_response_table[data_pin][self._command_handler.RESPONSE_TABLE_MODE] \
= self.I2C
else:
self._command_handler.analog_response_table[clk_pin][self._command_handler.RESPONSE_TABLE_MODE] \
= self.I2C
self._command_handler.analog_response_table[data_pin][self._command_handler.RESPONSE_TABLE_MODE] \
= self.I2C
def i2c_read(self, address, register, number_of_bytes, read_type):
"""
This method requests the read of an i2c device. Results are retrieved by a call to
i2c_get_read_data()
@param address: i2c device address
@param register: register number (can be set to zero)
@param number_of_bytes: number of bytes expected to be returned
@param read_type: I2C_READ or I2C_READ_CONTINUOUSLY
"""
data = [address, read_type, register & 0x7f, register >> 7,
number_of_bytes & 0x7f, number_of_bytes >> 7]
self._command_handler.send_sysex(self._command_handler.I2C_REQUEST, data)
def i2c_write(self, address, *args):
"""
Write data to an i2c device.
@param address: i2c device address
@param args: A variable number of bytes to be sent to the device
"""
data = [address, self.I2C_WRITE]
for item in args:
data.append(item)
self._command_handler.send_sysex(self._command_handler.I2C_REQUEST, data)
def i2c_stop_reading(self, address):
"""
This method stops an I2C_READ_CONTINUOUSLY operation for the i2c device address specified.
@param address: address of i2c device
"""
data = [address, self.I2C_STOP_READING]
self._command_handler.send_sysex(self._command_handler.I2C_REQUEST, data)
def i2c_get_read_data(self, address):
"""
This method retrieves the i2c read data as the result of an i2c_read() command.
@param address: i2c device address
@return: raw data read from device
"""
if address in self._command_handler.i2c_map:
return self._command_handler.i2c_map[address]
def pin_state_query(self, pin):
"""
This method issues a pin state query command. Data returned is retrieved via
a call to get_pin_state_query_results()
@param pin: pin number
"""
self._command_handler.send_sysex(self._command_handler.PIN_STATE_QUERY, [pin])
def play_tone(self, pin, tone_command, frequency, duration):
"""
This method will call the Tone library for the selected pin.
If the tone command is set to TONE_TONE, then the specified tone will be played.
Else, if the tone command is TONE_NO_TONE, then any currently playing tone will be disabled.
It is intended for a future release of Arduino Firmata
@param pin: Pin number
@param tone_command: Either TONE_TONE, or TONE_NO_TONE
@param frequency: Frequency of tone
@param duration: Duration of tone in milliseconds
@return: No return value
"""
# convert the integer values to bytes
if tone_command == self.TONE_TONE:
# duration is specified
if duration:
data = [tone_command, pin, frequency & 0x7f, frequency >> 7, duration & 0x7f, duration >> 7]
else:
data = [tone_command, pin, frequency & 0x7f, frequency >> 7, 0, 0]
self._command_handler.digital_response_table[pin][self._command_handler.RESPONSE_TABLE_MODE] = \
self.TONE
# turn off tone
else:
data = [tone_command, pin]
self._command_handler.send_sysex(self._command_handler.TONE_PLAY, data)
def refresh_report_version(self):
"""
This method will query firmata for the report version.
Retrieve the report version via a call to get_firmata_version()
"""
command = [self._command_handler.REPORT_VERSION]
self._command_handler.send_command(command)
def refresh_report_firmware(self):
"""
This method will query firmata to report firmware. Retrieve the report via a
call to get_firmata_firmware_version()
"""
self._command_handler.send_sysex(self._command_handler.REPORT_FIRMWARE, None)
def reset(self):
"""
This command sends a reset message to the Arduino. The response tables will be reinitialized
@return: No return value.
"""
# set all output pins to a value of 0
for pin in range(0, self._command_handler.total_pins_discovered):
if self._command_handler.digital_response_table[self._command_handler.RESPONSE_TABLE_MODE] \
== self.PWM:
self.analog_write(pin, 0)
elif self._command_handler.digital_response_table[self._command_handler.RESPONSE_TABLE_MODE] \
== self.SERVO:
self.analog_write(pin, 0)
elif self._command_handler.digital_response_table[self._command_handler.RESPONSE_TABLE_MODE] \
== self.TONE:
data = [self.TONE_NO_TONE, pin]
self._command_handler.send_sysex(self._command_handler.TONE_PLAY, data)
else:
self.digital_write(pin, 0)
self._command_handler.system_reset()
def set_analog_latch(self, pin, threshold_type, threshold_value):
"""
This method "arms" an analog pin for its data to be latched and saved in the latching table
@param pin: Analog pin number (value following an 'A' designator, i.e. A5 = 5
@param threshold_type: ANALOG_LATCH_GT | ANALOG_LATCH_LT | ANALOG_LATCH_GTE | ANALOG_LATCH_LTE
@param threshold_value: numerical value - between 0 and 1023
@return: True if successful, False if parameter data is invalid
"""
if self.ANALOG_LATCH_GT <= threshold_type <= self.ANALOG_LATCH_LTE:
if 0 <= threshold_value <= 1023:
self._command_handler.set_analog_latch(pin, threshold_type, threshold_value)
return True
else:
return False
def set_digital_latch(self, pin, threshold_type):
"""
This method "arms" a digital pin for its data to be latched and saved in the latching table
@param pin: Digital pin number
@param threshold_type: DIGITAL_LATCH_HIGH | DIGITAL_LATCH_LOW
@return: True if successful, False if parameter data is invalid
"""
if 0 <= threshold_type <= 1:
self._command_handler.set_digital_latch(pin, threshold_type)
return True
else:
return False
def set_pin_mode(self, pin, mode, pin_type):
"""
This method sets a pin to the desired pin mode for the pin_type.
It automatically enables data reporting.
NOTE: DO NOT CALL THIS METHOD FOR I2C. See i2c_config().
@param pin: Pin number (for analog use the analog number, for example A4: use 4)
@param mode: INPUT, OUTPUT, PWM, SERVO, ENCODER or TONE
@param pin_type: ANALOG or DIGITAL
@return: No return value
"""
command = [self._command_handler.SET_PIN_MODE, pin, mode]
self._command_handler.send_command(command)
#enable reporting for input pins
if mode == self.INPUT:
if pin_type == self.ANALOG:
# set analog response table to show this pin is an input pin
self._command_handler.analog_response_table[pin][self._command_handler.RESPONSE_TABLE_MODE] = \
self.INPUT
self.enable_analog_reporting(pin)
# if not analog it has to be digital
else:
self._command_handler.digital_response_table[pin][self._command_handler.RESPONSE_TABLE_MODE] = \
self.INPUT
self.enable_digital_reporting(pin)
else: # must be output - so set the tables accordingly
if pin_type == self.ANALOG:
self._command_handler.analog_response_table[pin][self._command_handler.RESPONSE_TABLE_MODE] = mode
else:
self._command_handler.digital_response_table[pin][self._command_handler.RESPONSE_TABLE_MODE] = mode
def set_sampling_interval(self, interval):
"""
This method sends the desired sampling interval to Firmata.
Note: Standard Firmata will ignore any interval less than 10 milliseconds
@param interval: Integer value for desired sampling interval in milliseconds
@return: No return value.
"""
data = [interval & 0x7f, interval >> 7]
self._command_handler.send_sysex(self._command_handler.SAMPLING_INTERVAL, data)
def servo_config(self, pin, min_pulse=544, max_pulse=2400):
"""
Configure a pin as a servo pin. Set pulse min, max in ms.
@param pin: Servo Pin.
@param min_pulse: Min pulse width in ms.
@param max_pulse: Max pulse width in ms.
@return: No return value
"""
self.set_pin_mode(pin, self.SERVO, self.OUTPUT)
command = [pin, min_pulse & 0x7f, min_pulse >> 7, max_pulse & 0x7f,
max_pulse >> 7]
self._command_handler.send_sysex(self._command_handler.SERVO_CONFIG, command)
def sonar_config(self, trigger_pin, echo_pin, ping_interval=50, max_distance=200):
"""
Configure the pins,ping interval and maximum distance for an HC-SR04 type device.
Single pin configuration may be used. To do so, set both the trigger and echo pins to the same value.
Up to a maximum of 6 SONAR devices is supported
If the maximum is exceeded a message is sent to the console and the request is ignored.
NOTE: data is measured in centimeters
@param trigger_pin: The pin number of for the trigger (transmitter).
@param echo_pin: The pin number for the received echo.
@param ping_interval: Minimum interval between pings. Lowest number to use is 33 ms.Max is 127
@param max_distance: Maximum distance in cm. Max is 200.
"""
if max_distance > 200:
max_distance = 200
max_distance_lsb = max_distance & 0x7f
max_distance_msb = max_distance >> 7
data = [trigger_pin, echo_pin, ping_interval, max_distance_lsb, max_distance_msb]
self.set_pin_mode(trigger_pin, self.SONAR, self.INPUT)
self.set_pin_mode(echo_pin, self.SONAR, self.INPUT)
# update the ping data map for this pin
if len(self._command_handler.active_sonar_map) > 6:
self.frame.show_msg(15)
return
else:
with self.data_lock:
self._command_handler.active_sonar_map[trigger_pin] = self.IGNORE
self._command_handler.send_sysex(self._command_handler.SONAR_CONFIG, data)
def stepper_config(self, steps_per_revolution, stepper_pins):
"""
Configure stepper motor prior to operation.
@param steps_per_revolution: number of steps per motor revolution
@param stepper_pins: a list of control pin numbers - either 4 or 2
"""
data = [self.STEPPER_CONFIGURE, steps_per_revolution & 0x7f, steps_per_revolution >> 7]
for pin in range(len(stepper_pins)):
data.append(stepper_pins[pin])
self._command_handler.send_sysex(self._command_handler.STEPPER_DATA, data)
def stepper_step(self, motor_speed, number_of_steps):
"""
Move a stepper motor for the number of steps at the specified speed
@param motor_speed: 21 bits of data to set motor speed
@param number_of_steps: 14 bits for number of steps & direction
positive is forward, negative is reverse
"""
if number_of_steps > 0:
direction = 1
else:
direction = 0
abs_number_of_steps = abs(number_of_steps)
data = [self.STEPPER_STEP, motor_speed & 0x7f, (motor_speed >> 7) & 0x7f, motor_speed >> 14,
abs_number_of_steps & 0x7f, abs_number_of_steps >> 7, direction]
self._command_handler.send_sysex(self._command_handler.STEPPER_DATA, data)
def stepper_request_library_version(self):
"""
Request the stepper library version from the Arduino.
To retrieve the version after this command is called, call
get_stepper_version
"""
data = [self.STEPPER_LIBRARY_VERSION]
self._command_handler.send_sysex(self._command_handler.STEPPER_DATA, data)
def __init__(self, frame, port_id='/dev/ttyUSB0'):
"""
The "constructor" instantiates the entire interface. It starts the operational threads for the serial
interface as well as for the command handler.
@param port_id: Communications port specifier (COM3, /dev/ttyACM0, etc)
"""
# Currently only serial communication over USB is supported, but in the future
# wifi and other transport mechanism support is anticipated
# reference pointer to the text area on the GUI
self.frame = frame
self.frame.show_msg(11)
frame.show_msg(12)
frame.text.see(END)
frame.update_idletasks()
# Instantiate the serial support class
self.transport = PyMataSerial(port_id, self.command_deque, frame)
# Attempt opening communications with the Arduino micro-controller
self.transport.open()
time.sleep(1)
# Start the data receive thread
self.transport.start()
# Instantiate the command handler
self._command_handler = PyMataCommandHandler(self, self.frame)
########################################################################
# constants defined locally from values contained in the command handler
########################################################################
# Data latch state constants to be used when accessing data returned from get_latch_data methods.
# The get_latch data methods return [pin_number, latch_state, latched_data, time_stamp]
# These three constants define possible values for the second item in the list, latch_state
# this pin will be ignored for latching - table initialized with this value
self.LATCH_IGNORE = self._command_handler.LATCH_IGNORE
# When the next pin value change is received for this pin, if it matches the latch criteria
# the data will be latched.
self.LATCH_ARMED = self._command_handler.LATCH_ARMED
# Data has been latched. Read the data to re-arm the latch.
self.LATCH_LATCHED = self._command_handler.LATCH_LATCHED
#
# These constants are used when setting a data latch.
# Latch threshold types
#
self.DIGITAL_LATCH_HIGH = self._command_handler.DIGITAL_LATCH_HIGH
self.DIGITAL_LATCH_LOW = self._command_handler.DIGITAL_LATCH_LOW
self.ANALOG_LATCH_GT = self._command_handler.ANALOG_LATCH_GT
self.ANALOG_LATCH_LT = self._command_handler.ANALOG_LATCH_LT
self.ANALOG_LATCH_GTE = self._command_handler.ANALOG_LATCH_GTE
self.ANALOG_LATCH_LTE = self._command_handler.ANALOG_LATCH_LTE
# constants to be used to parse the data returned from calling
# get_X_latch_data()
self.LATCH_PIN = 0
self.LATCH_STATE = 1
self.LATCHED_DATA = 2
self.LATCHED_TIME_STAMP = 3
# Start the command processing thread
self._command_handler.start()
# Command handler should now be prepared to receive replies from the Arduino, so go ahead
# detect the Arduino board
frame.show_msg(13)
frame.text.see(END)
frame.update_idletasks()
# perform board auto discovery
if not self._command_handler.auto_discover_board():
# board was not found so shutdown
frame.show_msg(17)
self._command_handler.stop()
self.transport.stop()
self._command_handler.join()
self.transport.join()
time.sleep(2)
