gps4ghat

GPS_4G_HAT_BG77X

Library

Python drivers for Finamon GPS 4G shield onboard devices and peripheral interfaces

• Quectel BG77/BG770 4G Modem
• Accelerometer MC3419/MC3479
• Other shield HW parts: inputs/outputs, button, LED

Examples

Basic examples showing how to work with Finamon GPS 4G shield onboard devices using Python.

• demo_echo.py
• demo_geofences.py
• demo_GPS_4G_HAT.py
• demo_mqtt.py

Prerequisites

Raspberry Pi Config

In your Raspberry Pi configuration within the Interfaces section, please make sure that

1. I2C is enabled
2. Serial Port is enabled
3. Serial Console is disabled

Global setup

If you prefer to setup your projects using global package installations, please take a look at the prerequisites below.

With newer versions of Python you might experience the message error: externally-managed-environment
In this case try using pip's argument --break-system-packages
or add the following lines to ~/.config/pip/pip.conf:
[global]
break-system-packages = true

• To be able to parse NMEA messages install package pynmea2:
  pip install pynmea2

• For access to SIM card account information install python-dotenv:
  pip install python-dotenv

Virtual Enivironment

If you prefer to setup your projects using virtual environments, the necessary steps to be able to run the examples are:

1. Download or clone the repository (see section below)
2. Open the termianl and change into the repository folder
3. Even using the virtual environment the project needs access to a global package to work with GPIOs
   • Run sudo apt update && sudo apt install python3-libgpiod
4. Now you can create the virtual environment python3 -m venv .venv --system-site-packages
   • The parameter --system-site-packages allows to access packages from outside of the virtual environment
5. Activate the environment via source .venv/bin/activate
   • (use the command deactivate to leave the virtual environment)
6. Install the dependencies to run the demo scripts python3 -m pip install pynmea2 python-dotenv pyserial smbus
7. Now you can continue with the installation steps in the following sections to install the GPS 4G HAT library and execute the demo scripts

Installation

• Clone git repository https://github.com/finamon-de/gps-4g-hat-library

• Change directory
  cd gps-4g-hat-library/gps4ghat/dist/

• Install gps4ghat python package
  pip install gps4ghat-0.1.0-py3-none-any.whl

Getting started

• Change directory to gps-4g-hat-library

• Copy example.env file to .env file and edit SIM account data:
  CONTEXT_APN
CONTEXT_USERNAME
CONTEXT_PASSWORD\

• Start examples
  python examples/demo_xxxx.py

Notes

• By default the GPS 4G HAT is configured to use the internal/onboard GSM antenna and the external GNSS RF antenna (that is part of the deliverables). You can ensure this configuration by having a look at the resistors close to antenna connectors.
• When you use your SIM card for the first time or after a long period, you may experience that the examples return a message containing +CEREG: 0,2. This message indicates that it was not possible to establish a connection with the base station but it is possible to retry - that's what the 2 indicates. When the connection is established the message will be +CEREG: 0,5, the 5 indicating that the connection is succesfully created. While testing different SIM cards, we expirienced (very) long timespans until the first connection to the base station was possible - up to 60 minutes sometimes. After the first successful connection reconnecting is not an issue.

Images

Data pins

Input pins

Output pins

Configuration to use the internal/onboard antennas

Configuration to use the external antenna connectors