ticlib is a pure-Python library to drive Pololu Tic stepper motor controllers over a serial, I²C, or USB connection.

Example code

from src.ticlib import TicUSB
from time import sleep

tic = TicUSB()

tic.halt_and_set_position(0)
tic.energize()
tic.exit_safe_start()

positions = [500, 300, 800, 0]
for position in positions:
    tic.set_target_position(position)
    while tic.get_current_position() != tic.get_target_position():
        sleep(0.1)

tic.deenergize()
tic.enter_safe_start()

Available controllers

Serial

The serial controller has a dependency on the pyserial library.

Example:

import serial
from src.ticlib import TicSerial

port_name = "/dev/ttyS0"
baud_rate = 9600
port = serial.Serial(port_name, baud_rate, timeout=0.1, write_timeout=0.1)

tic = TicSerial(port)

Instantiation parameters for TicSerial:

• port (required): Serial port used to communicate with the Tic.
• device_number (optional): Number of the device that you want to control. Use this if you have multiple devices connected to your serial line. Defaults to None.
• crc_for_commands (optional): If True, the library will append a CRC byte to every command sent to the Tic. Set this to True if your Tic's "Enable CRC for commands" setting is turned on. Defaults to False.
• crc_for_responses (optional): If True, the library will expect a CRC byte at the end of every response returned by the Tic. Set this to True if your Tic's "Enable CRC for responses" setting is turned on. Defaults to False.

For more details, see Pololu's official documentation on serial command encoding.

I²C

The I²C controller has a dependency on the smbus2 library.

Example:

from smbus2 import SMBus
from src.ticlib import TicI2C

bus = SMBus(3)
address = 14

tic = TicI2C(bus, address)

Instantiation parameters for TicI2C:

• bus (required): Your Tic's I²C bus. For example, SMBus(3) represents /dev/i2c-3.
• address (required): Address of the Tic, that is its device number.

Note: If you use a Raspberry Pi, make sure to follow the workaround described in the Pololu documentation.

For more details, see Pololu's official documentation on I²C command encoding.

USB

The USB controller has a dependency on the pyusb library.

Example:

from src.ticlib import TicUSB

tic = TicUSB()

Instantiation parameters for TicUSB:

• product (optional): USB product ID for your Tic. If None, the device will be automatically detected. Use this if multiple Tic devices are connected to your computer. The available options are: TIC_T825 (0x00b3), TIC_T834 (0x00b5), TIC_T500 (0x00bd), TIC_N825 (0x00c3), TIC_T249 (0x00c9), and TIC_36v4 (0x00cb). Defaults to None.
• serial_number (optional): The serial number (in string format) of your Tic. If None, the device will be automatically detected. Use this if multiple Tic devices are connected to your computer. Default to None.

For more details, see Pololu's official documentation on USB command encoding.

Commands:

Available commands:

tic.clear_driver_error()
tic.deenergize()
tic.energize()
tic.enter_safe_start()
tic.exit_safe_start()
tic.go_home(value)
tic.halt_and_hold()
tic.halt_and_set_position(value)
tic.reset()
tic.reset_command_timeout()
tic.set_agc_option(value)
tic.set_current_limit(value)
tic.set_decay_mode(value)
tic.set_max_acceleration(value)
tic.set_max_deceleration(value)
tic.set_max_speed(value)
tic.set_starting_speed(value)
tic.set_step_mode(value)
tic.set_target_position(value)
tic.set_target_velocity(value)

For more details, see the official command reference.

Variables

Available variables:

# General status  -------------------------------------
tic.get_error_occured()
tic.get_error_status()
tic.get_misc_flags()
tic.get_operation_state()

# Step planning ---------------------------------------
tic.get_acting_target_position()
tic.get_current_position()
tic.get_current_velocity()
tic.get_max_acceleration()
tic.get_max_deceleration()
tic.get_max_speed()
tic.get_planning_mode()
tic.get_starting_speed()
tic.get_target_position()
tic.get_target_velocity()
tic.get_time_since_last_step()

# Other -----------------------------------------------
tic.get_analog_reading_rx()
tic.get_analog_reading_scl()
tic.get_analog_reading_sda()
tic.get_analog_reading_tx()
tic.get_current_limit()
tic.get_decay_mode()
tic.get_device_reset()
tic.get_digital_readings()
tic.get_encoder_position()
tic.get_input_after_averaging()
tic.get_input_after_hysteresis()
tic.get_input_after_scaling()
tic.get_input_state()
tic.get_pin_states()
tic.get_rc_pulse()
tic.get_step_mode()
tic.get_vin_voltage()
tic.get_uptime()

# T249-only -------------------------------------------
tic.get_agc_bottom_current_limit()
tic.get_agc_current_boost_steps()
tic.get_agc_frequency_limit()
tic.get_agc_mode()
tic.get_last_motor_driver_error()

# 36v4-only -------------------------------------------
tic.get_last_hp_driver_errors()

For more details, see the official variable reference.

Settings

Available settings:

tic.settings.get_control_mode()

# Miscellaneous -------------------------------------------------
tic.settings.get_auto_clear_driver_error()
tic.settings.get_disable_safe_start()
tic.settings.get_ignore_err_line_high()
tic.settings.get_never_sleep()
tic.settings.get_vin_calibration()

# Soft error response -------------------------------------------
tic.settings.get_current_limit_during_error()
tic.settings.get_soft_error_position()
tic.settings.get_soft_error_response()

# Serial --------------------------------------------------------
tic.settings.get_serial_7bit_responses()
tic.settings.get_serial_14bit_device_number()
tic.settings.get_serial_alt_device_number()
tic.settings.get_serial_baud_rate()
tic.settings.get_serial_command_timeout()
tic.settings.get_serial_crc_for_commands()
tic.settings.get_serial_crc_for_responses()
tic.settings.get_serial_device_number()
tic.settings.get_serial_enable_alt_device_number()
tic.settings.get_serial_response_delay()

# Encoder -------------------------------------------------------
tic.settings.get_encoder_postscaler()
tic.settings.get_encoder_prescaler()
tic.settings.get_encoder_unlimited()

# Input conditioning --------------------------------------------
tic.settings.get_input_averaging_enabled()
tic.settings.get_input_hysteresis()

# RC and analog scaling -----------------------------------------
tic.settings.get_input_invert()
tic.settings.get_input_max()
tic.settings.get_input_min()
tic.settings.get_input_neutral_max()
tic.settings.get_input_neutral_min()
tic.settings.get_input_scaling_degree()
tic.settings.get_output_max()
tic.settings.get_output_min()

# Pin Configuration ---------------------------------------------
# SCL
tic.settings.get_scl_active_high()
tic.settings.get_scl_config()
tic.settings.get_scl_enable_analog()
tic.settings.get_scl_enable_pull_up()
tic.settings.get_scl_kill_switch()
tic.settings.get_scl_limit_switch_forward()
tic.settings.get_scl_limit_switch_reverse()
tic.settings.get_scl_pin_function()
# SDA
tic.settings.get_sda_active_high()
tic.settings.get_sda_config()
tic.settings.get_sda_enable_analog()
tic.settings.get_sda_enable_pull_up()
tic.settings.get_sda_kill_switch()
tic.settings.get_sda_limit_switch_forward()
tic.settings.get_sda_limit_switch_reverse()
tic.settings.get_sda_pin_function()
# TX
tic.settings.get_tx_active_high()
tic.settings.get_tx_config()
tic.settings.get_tx_enable_analog()
tic.settings.get_tx_kill_switch()
tic.settings.get_tx_limit_switch_forward()
tic.settings.get_tx_limit_switch_reverse()
tic.settings.get_tx_pin_function()
# RX
tic.settings.get_rx_active_high()
tic.settings.get_rx_config()
tic.settings.get_rx_enable_analog()
tic.settings.get_rx_kill_switch()
tic.settings.get_rx_limit_switch_forward()
tic.settings.get_rx_limit_switch_reverse()
tic.settings.get_rx_pin_function()
# RC
tic.settings.get_rc_active_high()
tic.settings.get_rc_config()
tic.settings.get_rc_kill_switch()
tic.settings.get_rc_limit_switch_forward()
tic.settings.get_rc_limit_switch_reverse()

# Motor ---------------------------------------------------------
tic.settings.get_current_limit()
tic.settings.get_decay_mode()
tic.settings.get_invert_motor_direction()
tic.settings.get_max_acceleration()
tic.settings.get_max_deceleration()
tic.settings.get_max_speed()
tic.settings.get_starting_speed()
tic.settings.get_step_mode()

# Homing --------------------------------------------------------
tic.settings.get_auto_homing()
tic.settings.get_auto_homing_forward()
tic.settings.get_homing_speed_away()
tic.settings.get_homing_speed_towards()

# T249-only -----------------------------------------------------
tic.settings.get_agc_bottom_current_limit()
tic.settings.get_agc_current_boost_steps()
tic.settings.get_agc_mode()
tic.settings.get_agc_frequency_limit()

# 36v4-only -----------------------------------------------------
tic.settings.get_hp_current_trip_blanking_time()
tic.settings.get_hp_decay_mode()
tic.settings.get_hp_enable_adaptive_blanking_time()
tic.settings.get_hp_enable_unrestricted_current_limits()
tic.settings.get_hp_fixed_off_time()
tic.settings.get_hp_mixed_decay_transition_time()

Modifying settings is currently not supported.

For more details, see the official settings reference.