# Python-Arduino-Command-API **Repository Path**: mirrors_thearn/Python-Arduino-Command-API ## Basic Information - **Project Name**: Python-Arduino-Command-API - **Description**: A Python library for communicating with Arduino microcontroller boards - **Primary Language**: Unknown - **License**: MIT - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 1 - **Forks**: 0 - **Created**: 2022-01-07 - **Last Updated**: 2025-12-04 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README # Arduino-Python3 Command API This API is forked from the original [Python Arduino Command API](https://github.com/thearn/Python-Arduino-Command-API) to add support for Python 3. The Arduino-Python3 Command API is a lightweight Python library for communicating with [Arduino microcontroller boards](http://www.arduino.cc/) from a connected computer using standard serial IO, either over a physical wire or wirelessly. It is written using a custom protocol, similar to [Firmata](http://firmata.org/wiki/Main_Page). This allows a user to quickly prototype programs for Arduino using Python code, or to simply read/control/troubleshoot/experiment with hardware connected to an Arduino board without ever having to recompile and reload sketches to the board itself. Method names within the Arduino-Python3 Command API are designed to be as close as possible to their Arduino programming language counterparts ## Simple usage example (LED blink) ```python #!/usr/bin/env python """ Blinks an LED on digital pin 13 in 1 second intervals """ from Arduino import Arduino import time board = Arduino() # plugged in via USB, serial com at rate 115200 board.pinMode(13, "OUTPUT") while True: board.digitalWrite(13, "LOW") time.sleep(1) board.digitalWrite(13, "HIGH") time.sleep(1) ``` ## Requirements: - [Python](http://python.org/) 3.7 tested on Windows and macOS. - [pyserial](http://pyserial.sourceforge.net/) 2.6 or higher - Any [Arduino compatible microcontroller](https://www.sparkfun.com/categories/242) with at least 14KB of flash memory ## Installation: Either run `pip install arduino-python3` from a command line, or run `python setup.py build install` from the source directory to install this library. ## Setup: 1. Verify that your Arduino board communicates at the baud rate specified in the `setup()` function (line 407) in `prototype.ino`. Change it there if necessary. 2. Load the `prototype.ino` sketch onto your Arduino board, using the Arduino IDE. 3. Set up some kind of serial I/O communication between the Arduino board and your computer (via physical USB cable, Bluetooth, xbee, etc. + associated drivers) 4. Add `from Arduino import Arduino` into your python script to communicate with your Arduino For a collection of examples, see `examples.py`. This file contains methods which replicate the functionality of many Arduino demo sketches. ## Testing: The `tests` directory contains some basic tests for the library. Extensive code coverage is a bit difficult to expect for every release, since a positive test involves actually connecting and issuing commands to a live Arduino, hosting any hardware required to test a particular function. But a core of basic communication tests should at least be maintained here and used before merging into the `master` branch. After installation, the interactive tests can be run from the source directory: ```bash $ python tests/test_main.py ``` Automated tests can be run from the source directory with: ```bash $ python tests/test_arduino.py ``` ## Classes - `Arduino(baud)` - Set up communication with currently connected and powered Arduino. ```python board = Arduino("115200") #Example ``` The device name / COM port of the connected Arduino will be auto-detected. If there are more than one Arduino boards connected, the desired COM port can be also be passed as an optional argument: ```python board = Arduino("115200", port="COM3") #Windows example ``` ```python board = Arduino("115200", port="/dev/tty.usbmodemfa141") #OSX example ``` A time-out for reading from the Arduino can also be specified as an optional argument: ```python board = Arduino("115200", timeout=2) #Serial reading functions will #wait for no more than 2 seconds ``` ## Methods **Digital I/O** - `Arduino.digitalWrite(pin_number, state)` turn digital pin on/off - `Arduino.digitalRead(pin_number)` read state of a digital pin ```python #Digital read / write example board.digitalWrite(13, "HIGH") #Set digital pin 13 voltage state_1 = board.digitalRead(13) #Will return integer 1 board.digitalWrite(13, "LOW") #Set digital pin 13 voltage state_2 = board.digitalRead(13) #Will return integer 0 ``` - `Arduino.pinMode(pin_number, io_mode)` set pin I/O mode - `Arduino.pulseIn(pin_number, state)` measures a pulse - `Arduino.pulseIn_set(pin_number, state)` measures a pulse, with preconditioning ```python #Digital mode / pulse example board.pinMode(7, "INPUT") #Set digital pin 7 mode to INPUT duration = board.pulseIn(7, "HIGH") #Return pulse width measurement on pin 7 ``` **Analog I/O** - `Arduino.analogRead(pin_number)` returns the analog value - `Arduino.analogWrite(pin_number, value)` sets the analog value ```python #Analog I/O examples val=board.analogRead(5) #Read value on analog pin 5 (integer 0 to 1023) val = val / 4 # scale to 0 - 255 board.analogWrite(11) #Set analog value (PWM) based on analog measurement ``` **Shift Register** - `Arduino.shiftIn(dataPin, clockPin, bitOrder)` shift a byte in and returns it - `Arduino.shiftOut(dataPin, clockPin, bitOrder, value)` shift the given byte out `bitOrder` should be either `"MSBFIRST"` or `"LSBFIRST"` **Servo Library Functionality** Support is included for up to 8 servos. - `Arduino.Servos.attach(pin, min=544, max=2400)` Create servo instance. Only 8 servos can be used at one time. - `Arduino.Servos.read(pin)` Returns the angle of the servo attached to the specified pin - `Arduino.Servos.write(pin, angle)` Move an attached servo on a pin to a specified angle - `Arduino.Servos.writeMicroseconds(pin, uS)` Write a value in microseconds to the servo on a specified pin - `Arduino.Servos.detach(pin)` Detaches the servo on the specified pin ```python #Servo example board.Servos.attach(9) #declare servo on pin 9 board.Servos.write(9, 0) #move servo on pin 9 to 0 degrees print board.Servos.read(9) # should be 0 board.Servos.detach(9) #free pin 9 ``` **Software Serial Functionality** - `Arduino.SoftwareSerial.begin(ss_rxPin, ss_txPin, ss_device_baud)` initialize software serial device on specified pins. Only one software serial device can be used at a time. Existing software serial instance will be overwritten by calling this method, both in Python and on the Arduino board. - `Arduino.SoftwareSerial.write(data)` send data using the Arduino 'write' function to the existing software serial connection. - `Arduino.SoftwareSerial.read()` returns one byte from the existing software serial connection ```python #Software serial example board.SoftwareSerial.begin(0, 7, "19200") # Start software serial for transmit only (tx on pin 7) board.SoftwareSerial.write(" test ") #Send some data response_char = board.SoftwareSerial.read() #read response character ``` **EEPROM** - `Arduino.EEPROM.read(address)` reads a byte from the EEPROM - `Arduino.EEPROM.write(address, value)` writes a byte to the EEPROM - `Arduino.EEPROM.size()` returns size of the EEPROM ```python #EEPROM read and write examples location = 42 value = 10 # 0-255(byte) board.EEPROM.write(location, 10) print(board.EEPROM.read(location)) print('EEPROM size {size}'.format(size=board.EEPROM.size())) ``` **Misc** - `Arduino.close()` closes serial connection to the Arduino. ## To-do list: - Expand software serial functionality (`print()` and `println()`) - Add simple reset functionality that zeros out all pin values - Add I2C / TWI function support (Arduino `Wire.h` commands) - Include a wizard which generates 'prototype.ino' with selected serial baud rate and Arduino function support (to help reduce memory requirements). - Multi-serial support for Arduino mega (`Serial1.read()`, etc)