pygpsclient 0.2.1

PyGPSClient GNSS/GPS Graphical Client

PyGPSClient

PyGPSClient is a graphical GNSS/GPS testing and diagnostic client application written entirely in Python and tkinter.

The application runs on any platform which supports a Python3 interpreter (>=3.6) and tkinter (>=8.6) GUI framework, including Windows, MacOS, Linux and Raspberry Pi OS. It displays location and diagnostic data from any NMEA or UBX (u-blox ©) compatible GNSS/GPS device over a standard serial (UART) or USB port, or from a previously-saved datalog file, in addition to providing a small but useful subset of the configuration functionality in u-blox's Windows-only u-center tool.

This is a personal project and I have no affiliation whatsoever with u-blox ©.

Features:

1. Supports both NMEA and UBX protocols. It uses the existing pynmea2 library for NMEA parsing and implements a new pyubx2 library for UBX parsing.
2. Capable of reading from serial/USB port or previously-saved datalog file.
3. Configurable GUI with selectable and resizeable widgets.
4. Expandable banner widget showing key navigation information.
5. Serial console widget showing either raw or parsed data stream.
6. Skyview widget showing current satellite visibility and position (elevation / azimuth).
7. Graphview widget showing current satellite reception (signal-to-noise ratio).
8. Mapview widget with location marker, showing either a static Mercator world map, or an optional dynamic web-based map downloaded via a MapQuest API (requires an Internet connection and free MapQuest API Key).
9. Data logging.
10. UBX Configuration Dialog, with the ability to send a variety of UBX configuration messages to u-blox GNSS devices. This includes the facility to add user-defined preset configuration messages - see instructions under installation below.

UBX Configuration Facilities

The UBX Configuration Dialog currently supports the following UBX configuration commands:

1. CFG-PRT sets baudrate and inbound/outbound protocols across all available ports (note that an active USB port will always report a baudrate of 0).
2. CFG-MSG sets message rates per port for NMEA protocol messages (standard & proprietary) and UBX protocol messages.
3. PRESET commands support a variety of preset and user-defined commands - see user defined presets

An icon to the right of each 'SEND' button indicates the latest polled state of the displayed configuration (pending, confirmed or warning). A warning icon may simply indicate that this particular configuration message type is not supported by your receiver (typically accompanied by an ACK-NAK response). NB this is not a 100% reliable indication as the UBX protocol does not support explicit command handshaking, and confirmation responses can occasionally get lost or delayed in heavy inbound traffic. To ensure timely confirmation responses, try temporarily disabling periodic inbound traffic using the preset commands provided.

How to Use

• To connect to a listed serial device, select the device from the listbox and click . The application will endeavour to pre-select a recognised GNSS/GPS device but this doesn't always work on all platforms.
• To stream from a previously-saved datalog (pygps*.log) file, click and select the file.
• To disconnect from a serial device or datalog file, click .
• To display the UBX Configuration Dialog (only available when connected to a UBX serial device), click , or go to Menu..Options.
• To show or hide the various widgets, go to Menu..View and click on the relevant widget.

Glossary of Terms

• utc - coordinated universal time
• siv - satellites in view
• sip - satellites used in position solution
• dop - dilution of precision (pdop - position, hdop - horizontal, vdop - vertical)
• acc - accuracy of location in real units (hacc - horizontal, vacc - vertical)

Current Status

Alpha. Main application and widgets are fully functional for both NMEA and UBX protocols.

Known Issues:

1. Application menu options can occasionally become momentarily unresponsive in heavy inbound traffic due to serial read blocking. This is in hand.

Constructive feedback welcome.

Installation

In the following, python & pip refer to the python3 executables. You may need to type python3 or pip3, depending on your particular environment.

Dependencies

See requirements.txt.

On Windows and MacOS, pip, tkinter and the necessary imaging libraries are generally packaged with Python. On some Linux distributions like Ubuntu 18+ and Raspberry Pi OS, they may need to be installed separately, e.g.:

sudo apt-get install python3-pip python3-tk python3-pil python3-pil.imagetk

The following python libraries are required (these will be installed automatically if using pip to install PyGPSClient):

python -m pip install pyubx2 pyserial pynmea2 Pillow requests

User Privileges

To access the serial port on most linux platforms, you will need to be a member of the tty and dialout groups. Other than this, no special privileges are required.

1. Install using pip

The easiest way to install the latest version of PyGPSClient is via pip:

python -m pip install --upgrade PyGPSClient

To run the appliation, if the python3 site_packages are in your PATH, simply type python -m pygpsclient.

If not, type python -m \full_path_to_site_packages\pygpsclient.

Tip: to find the site_packages location, type pip show PyGPSClient and look for the Location: entry in the response, e.g.

Location: /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages

2. Manual installation

To install manually, download and unzip this repository and run:

python -m /path_to_folder/foldername/pygpsclient

e.g. if you downloaded and unzipped to a folder named PyGPSClient-0.2.0, run:

python -m /path_to_folder/PyGPSClient-0.2.0/pygpsclient.

MapQuest API Key

To use the optional dynamic web-based mapview facility, you need to request and install a MapQuest API key. The free edition of this API allows for up to 15,000 transactions/month (roughly 500/day) on a non-commercial basis. For this reason, the map refresh rate is intentionally limited to 1/minute to avoid exceeding the free transaction limit under normal use. NB: this facility is not intended to be used for real time navigational purposes.

Once you have received the API key (a 32-character alphanumeric string), copy it to a file named mqapikey (lower case, no extension) and place this file in the user's home directory.

User Defined Presets

The UBX Configuration Dialog includes the facility to send user-defined preset UBX configuration messages. These can be set up by adding appropriate comma-delimited message descriptions and payload definitions to a file named ubxpresets (lower case, no extension), and then placing this file in the user's home directory. The message definition comprises a free-format text description (avoid embedded commas) followed by one or more pyubx2 UBXMessage constructors, i.e.

1. ubx_class as a string e.g. CFG (must be a valid class from pyubx2.UBX_CONFIG_CATEGORIES)
2. ubx_id as a string e.g. CFG-MSG (must be a valid id from pyubx2.UBX_CONFIG_MESSAGES)
3. payload as a hexadecimal string e.g. f004010100010100
4. mode as an integer (1 = SET, 2 = POLL)

Multiple commands can be concatenated on a single line. An illustrative example is given below:

CFG-MSG Enable RMC message, CFG, CFG-MSG, f004010100010100, 1
CFG-MSG Enable VTG message, CFG, CFG-MSG, f005010100010100, 1
CFG-MSG Enable UBX00 & UBX03 messages, CFG, CFG-MSG, f100010100010100, 1, CFG, CFG-MSG, f103010100010100, 1

License

BSD 3-Clause License

Copyright (c) 2020, SEMU Consulting All rights reserved.

Application icons from iconmonstr ©.

Author Information

[e-mail]