GPS module data reading in Raspberry Pi - Mini Project: Build & Apply

GPS Module Data Reading

📖 Scenario: You have a Raspberry Pi connected to a GPS module. The GPS module sends location data as NMEA sentences over a serial connection. You want to read this data and extract the latitude and longitude.

🎯 Goal: Build a simple Python program that reads raw GPS data from the serial port, filters for GPGGA sentences, and extracts the latitude and longitude values.

📋 What You'll Learn

Create a serial connection to the GPS module

Read lines of data from the serial port

Identify GPGGA sentences in the data

Extract latitude and longitude from the GPGGA sentence

Print the extracted latitude and longitude

💡 Why This Matters

🌍 Real World

GPS modules are used in navigation, tracking, and location-based services. Reading GPS data on Raspberry Pi helps build projects like vehicle trackers, weather balloons, or outdoor robots.

💼 Career

Understanding serial communication and parsing GPS data is useful for embedded systems engineers, IoT developers, and robotics programmers.

1

Set up serial connection to GPS module

Import the serial module and create a serial connection called gps_serial with port "/dev/ttyS0" and baud rate 9600.

Raspberry Pi

# Import serial and create gps_serial connection
# Your code here

Hint

Use serial.Serial(port, baudrate) to create the connection.

2

Read a line of data from the GPS module

Use gps_serial.readline() to read one line of data from the GPS module and decode it to a string called line.

Raspberry Pi

import serial

gps_serial = serial.Serial("/dev/ttyS0", 9600)

# Read one line from gps_serial and decode it
# Your code here

Hint

Use decode('ascii', errors='replace') to convert bytes to string safely.

3

Check for GPGGA sentence and extract latitude and longitude

Check if line starts with "$GPGGA". If yes, split line by commas into parts. Extract latitude from parts[2] and longitude from parts[4].

Raspberry Pi

import serial

gps_serial = serial.Serial("/dev/ttyS0", 9600)

line = gps_serial.readline().decode('ascii', errors='replace').strip()

# Check if line starts with "$GPGGA" and extract latitude and longitude
# Your code here

Hint

Use startswith to check the sentence type and split(",") to separate fields.

4

Print the extracted latitude and longitude

Print the latitude and longitude variables using print(f"Latitude: {latitude}, Longitude: {longitude}").

Raspberry Pi

import serial

gps_serial = serial.Serial("/dev/ttyS0", 9600)

line = gps_serial.readline().decode('ascii', errors='replace').strip()

if line.startswith("$GPGGA"):
    parts = line.split(",")
    latitude = parts[2]
    longitude = parts[4]

# Print latitude and longitude
# Your code here

Hint

Use an f-string to format the output nicely.