University:
Eastern Kentucky University
Course:
CSC 189 | Computing Concepts and Programming
Academic year:

2021
Views:

431

Pages:

6
Author:

Hallie Randolph

CHAPTER 4 Tools 4.1 serial.tools.list_ports This module can be executed to get a list of ports (python -m serial.tools.list_ports). It also contains the following functions. serial.tools.list_ports.comports(include_links=False) Parameters include_links (bool) – include symlinks under /dev when they point to a serial port Returns a list containing ListPortInfo objects. The function returns a list of ListPortInfo objects. Items are returned in no particular order. It may make sense to sort the items. Also note that the reported strings are different across platforms and operating systems, even for the same device. Note: Support is limited to a number of operating systems. On some systems description and hardware ID will not be available (None). Under Linux, OSX and Windows, extended information will be available for USB devices (e.g. the ListPortInfo.hwid string contains VID:PID, SER (serial number), LOCATION (hierarchy), which makes them searchable via grep(). The USB info is also available as attributes of ListPortInfo. If include_links is true, all devices under /dev are inspected and tested if they are a link to a known serial port device. These entries will include LINK in their hwid string. This implies that the same device listed twice, once under its original name and once under linked name. Platform Posix (/dev files) Platform Linux (/dev files, sysfs) Platform OSX (iokit) Platform Windows (setupapi, registry) pySerial Documentation, Release 3.4 serial.tools.list_ports.grep(regexp, include_links=False) Parameters • regexp – regular expression (see stdlib re) • include_links (bool) – include symlinks under /dev when they point to a serial port Returns an iterable that yields ListPortInfo objects, see also comports(). Search for ports using a regular expression. Port name, description and hwid are searched (case insensitive). The function returns an iterable that contains the same data that comports() generates, but includes only those entries that match the regexp. class serial.tools.list_ports.ListPortInfo This object holds information about a serial port. It supports indexed access for backwards compatibility, as in port, desc, hwid = info. device Full device name/path, e.g. /dev/ttyUSB0. This is also the information returned as first element when accessed by index. name Short device name, e.g. ttyUSB0. description Human readable description or n/a. This is also the information returned as second element when accessed by index. hwid Technical description or n/a. This is also the information returned as third element when accessed by index. USB specific data, these are all None if it is not an USB device (or the platform does not support extended info). vid USB Vendor ID (integer, 0. . . 65535). pid USB product ID (integer, 0. . . 65535). serial_number USB serial number as a string. location USB device location string (“-[-]. . . ”) manufacturer USB manufacturer string, as reported by device. product USB product string, as reported by device. interface Interface specific description, e.g. used in compound USB devices. Comparison operators are implemented such that the ListPortInfo objects can be sorted by device. Strings are split into groups of numbers and text so that the order is “natural” (i.e. com1 < com2 < com10). Command line usage Help for python -m serial.tools.list_ports: Chapter 4. Tools pySerial Documentation, Release 3.4 usage: list_ports.py [-h] [-v] [-q] [-n N] [-s] [regexp] Serial port enumeration positional arguments: regexp only show ports that match this regex optional arguments: -h, --help -v, --verbose -q, --quiet -n N -s, --include-links show this help message and exit show more messages suppress all messages only output the N-th entry include entries that are symlinks to real devices Examples: • List all ports with details: $ python -m serial.tools.list_ports -v /dev/ttyS0 desc: ttyS0 hwid: PNP0501 /dev/ttyUSB0 desc: CP2102 USB to UART Bridge Controller hwid: USB VID:PID=10C4:EA60 SER=0001 LOCATION=2-1.6 2 ports found • List the 2nd port matching a USB VID:PID pattern: $ python -m serial.tools.list_ports 1234:5678 -q -n 2 /dev/ttyUSB1 New in version 2.6. Changed in version 3.0: returning ListPortInfo objects instead of a tuple 4.2 serial.tools.miniterm This is a console application that provides a small terminal application. Miniterm itself does not implement any terminal features such as VT102 compatibility. However it may inherit these features from the terminal it is run. For example on GNU/Linux running from an xterm it will support the escape sequences of the xterm. On Windows the typical console window is dumb and does not support any escapes. When ANSI.sys is loaded it supports some escapes. The default is to filter terminal control characters, see --filter for different options. Miniterm: --- Miniterm on /dev/ttyS0: 9600,8,N,1 ----- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H --- Command line options can be given so that binary data including escapes for terminals are escaped or output as hex. Miniterm supports RFC 2217 remote serial ports and raw sockets using URL Handlers such as rfc2217:// : respectively socket://: as port argument when invoking. Command line options python -m serial.tools.miniterm -h: 4.2. serial.tools.miniterm pySerial Documentation, Release 3.4 usage: miniterm.py [-h] [--parity {N,E,O,S,M}] [--rtscts] [--xonxoff] [--rts RTS] [--dtr DTR] [-e] [--encoding CODEC] [-f NAME] [--eol {CR,LF,CRLF}] [--raw] [--exit-char NUM] [--menu-char NUM] [-q] [--develop] [port] [baudrate] Miniterm - A simple terminal program for the serial port. positional arguments: port baudrate serial port name set baud rate, default: 9600 optional arguments: -h, --help show this help message and exit port settings: --parity {N,E,O,S,M} --rtscts --xonxoff --rts RTS --dtr DTR --ask set parity, one of {N E O S M}, default: N enable RTS/CTS flow control (default off) enable software flow control (default off) set initial RTS line state (possible values: 0, 1) set initial DTR line state (possible values: 0, 1) ask again for port when open fails data handling: -e, --echo --encoding CODEC enable local echo (default off) set the encoding for the serial port (e.g. hexlify, Latin1, UTF-8), default: UTF-8 -f NAME, --filter NAME add text transformation --eol {CR,LF,CRLF} end of line mode --raw Do no apply any encodings/transformations hotkeys: --exit-char NUM --menu-char NUM diagnostics: -q, --quiet --develop Unicode of special character that is used to exit the application, default: 29 Unicode code of special character that is used to control miniterm (menu), default: 20 suppress non-error messages show Python traceback on error Available filters (--filter option): • colorize: Apply different colors for received and echo • debug: Print what is sent and received • default: remove typical terminal control codes from input • direct: do-nothing: forward all data unchanged • nocontrol: Remove all control codes, incl. CR+LF • printable: Show decimal code for all non-ASCII characters and replace most control codes Miniterm supports some control functions while being connected. Typing Ctrl+T Ctrl+H when it is running shows the help text: Chapter 4. Tools pySerial Documentation, Release 3.4 ----------------------------------------------- pySerial (3.0a) - miniterm - help Ctrl+] Exit program Ctrl+T Menu escape key, followed by: Menu keys: Ctrl+T Send the menu character itself to remote Ctrl+] Send the exit character itself to remote Ctrl+I Show info Ctrl+U Upload file (prompt will be shown) Ctrl+A encoding Ctrl+F edit filters Toggles: Ctrl+R RTS Ctrl+D DTR Ctrl+B BREAK Ctrl+E echo Ctrl+L EOL Port p 7 N 1 b x r settings (Ctrl+T followed by the following): change port 8 set data bits E O S M change parity (None, Even, Odd, Space, Mark) 2 3 set stop bits (1, 2, 1.5) change baud rate X disable/enable software flow control R disable/enable hardware flow control Ctrl+T s suspends the connection (port is opened) and reconnects when a key is pressed. This can be used to temporarily access the serial port with an other application, without exiting miniterm. If reconnecting fails it is also possible to exit (Ctrl+]) or change the port (p). Changed in version 2.5: Added Ctrl+T menu and added support for opening URLs. Changed in version 2.6: File moved from the examples to serial.tools.miniterm. Changed in version 3.0: Apply encoding on serial port, convert to Unicode for console. Added new filters, default to stripping terminal control sequences. Added --ask option. 4.2. serial.tools.miniterm pySerial Documentation, Release 3.4 Chapter 4. Tools