This Python library allows interacting with a stepper motor that rotates a stage. The stepper motor is connected to a Sparkfun driver which is itself connected to an Arduino microcontroller.
arduino_pytwister has been developed for Python 3.
conda create -n envname python>=3.7
conda activate envname
pip install .On Linux, add yourself to the dialoutgroup
sudo usermod -a -G dialout $USERarduino_pytwister expects to interact with an Arduino Uno. The latter is connected to an EasyDriver Stepper Motor Driver - ROB-12779 by SparkFun Electronics.
The wiring is as follows:
Connect the arduino to the computer USB and to a power source.
Open the ArduinoPyTwisterFirmware/ArduinoPyTwisterFirmware.ino with the Arduino IDE software and upload it to the Arduino.
The package provides the following key functions:
get_comport_list: wrapper function to identify available serial portsget_arduino_ports: function to identify serial ports linked to connected arduinosscan_list_for_arduinopytwister: function to identify the serial port linked to a connected arduino with the correctArduinoPyTwisterFirmware.inocode uploaded.get_serial_object_to_arduino: function to obtain a serial object that can be used to communicate with the arduinorotate_by_steps: the function to instruct rotation
An example of a simple interation would be:
import pytwister as pt
port_list = pt.arduino.get_comport_list()
arduino_ports = pt.arduino.get_arduino_ports(port_list)
twister_port = pt.arduino.scan_list_for_arduinopytwister(arduino_ports)
ser = pt.arduino.get_serial_object_to_arduino(twister_port)
pt.arduino.rotate_by_steps(ser, -200)
pt.arduino.rotate_by_steps(ser, 200)The number of steps can be any integer in the range [-32768,32767].
Each step corresponds to 0.225° (degrees).
The Twister convenience class gives a high-level control interface.
An example of the same simple iteration would be:
import pytwister as pt
twister = pt.Twister()
twister.rotate_rel(45)
twister.rotate_abs(0)Conversion table for Sparkfun Easy Driver in eigth-step mode:
| steps | angle increment |
|---|---|
| 1 | 1.8°/8 =0.225° |
| 8 | 1.8° |
| 16 | 3.6° |
| 80 | 18° |
| 100 | 22.5° |
| 200 | 45° |
| 400 | 90° |
| 800 | 180° |
| 1600 | 360° |
This software is provided as-is.
Extensions should be accompanied by a test and clear function/class headers. Tests are gathered in test_arduino_twister.py
python3 -m unittest discover testsThe tests are run in "dummy" mode and there is currently no requirement that an arduino is connected.
Michael Liebling Idiap Research Institute April 2023
Francois Marelli Idiap Research Institute April 2023
inspired by related projects (µmanager, etc.)
BSD-3