HostPort-python

Python binding of the HostPort class for communication from and to the microcontroller.

This is the (Python) host-side implementation of the Host Port class. The class is internally implemented in C++ and interfaced to Pythn using Boost.Python to generate a dynamic library importable in Python as a module. The Python module is thus just a wrapper around a C++ class.

Tested on Windows 10, Linux (ArchLinux) and Rasberry (with ArchLinuxARM) with Python 3.10.

Contens

• ./src: C/C++ source files
• ./include: C/C++ include files
• ./.vscode: setting folder for Visual Studio Code
• Makefile: makefile to compile and buid the dynamic library
• testing.py: testing Python script for the Host Port class
• README.md: this file

Quick start

The package is named hostport and requires having the numpy Python package installed (tested with 1.24.1 version). You may install numpy using pip with (may require root permission)

pip install -r requirements.txt

Usage for the Host Port class is the following.

# Import the python modules
import hostport
import numpy as np

# Variables
port = 3 #serial port
baud = 115200 #baudrate
len = 64 #size of the buffer to read
data = np.array([0, 1, 2, 3, 4, 5], dtype=np.single) #buffer to write

# Instantiate a new object
h = hostport.HostPort()

# Start the communication
flag = h.begin(port, baud)
# flag = h.begin(port, baud, header, terminator) #set also header and terminator
# flag = h.begin(port, baud, header, terminator, timeout) #set also timeout

# read 'len' elements of single, return true if success
data_read = np.empty(len, dtype=np.single) #buffer must be defined as a numpy array
flag = h.read(data_read)

# write buffer (must be a numpy array)
flag = h.write(data)

To check the connection status:

# Check initialization
if not h.isInit(): #or hostport.isInit or hostport.begin(port, baud)
    print('Unable to connect')

# Check read or write
if not flag:
    print('Unable to read or write')

To show all properties:

# Show all properties
print(h)

To restart and flush the port

# Restart
h.restart()

# Flush
h.flush()

Finally, to close and clear

# Close
h.close()

In addition, a number of set & get methods is provided (use restart after set to make the change effective):

# Set methods
h.setPort(3)
h.setBaud(9600)
h.setHeader(0xABDE1234)
h.setTerminator(0x1234ABCD)
h.setTerminator(200)
h.restart() # Must use restart to make the change effective

# Get methods
print(h.getPort())
print(h.getBaud())
print(h.isInit())
print(hex(h.getHeader()))
print(hex(h.getTerminator()))
print(hex(h.getTimeout()))

Building

Pre-requisites for building are

• Python3
• Boost.Python
• Make

For example, on ArchLinux you can install via pacman using

pacman -S python3 boost make

Compilation is performed using the Makefile

make

Before using the Makefile, change library and include so as to match your Python version (3.10 is used at the moment). For building in Windows you may use Mingw-w64 with MSYS2 (requires mingw-w64-x86_64-boost).

Other make commands are:

• make clean to clean
• make remake to clean and make
• make test to run the testing.py script for testing
• make all to make and test

TODO list

• Implement boolean operator in Python binding