Iot-protocolsHow-ToBeginner · 4 min read

How to Use GPS Module with Raspberry Pi: Setup and Code

To use a GPS module with a Raspberry Pi, connect the module's TX and RX pins to the Pi's UART pins, enable the serial interface, and use a Python library like gpsd or pyserial to read GPS data. You can parse the NMEA sentences to get location, time, and speed information.

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Syntax

Here is the basic Python syntax to read GPS data from the serial port on Raspberry Pi:

import serial: Imports the serial communication library.
serial.Serial(port, baudrate): Opens the serial port connected to the GPS module.
readline(): Reads one line of GPS data (NMEA sentence).
decode(): Converts bytes to string for parsing.

python

import serial

# Open serial port (usually /dev/serial0 or /dev/ttyAMA0)
ser = serial.Serial('/dev/serial0', 9600, timeout=1)

while True:
    line = ser.readline().decode('ascii', errors='replace')
    print(line.strip())

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Example

This example shows how to read and print raw GPS NMEA sentences from the GPS module connected to Raspberry Pi's UART serial port.

python

import serial
import time

# Setup serial connection to GPS module
ser = serial.Serial('/dev/serial0', 9600, timeout=1)

try:
    while True:
        line = ser.readline().decode('ascii', errors='replace').strip()
        if line.startswith('$GPGGA'):
            print('GPS Fix Data:', line)
        time.sleep(1)
except KeyboardInterrupt:
    ser.close()
    print('Serial connection closed.')

Output

GPS Fix Data: $GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 GPS Fix Data: $GPGGA,123520,4807.039,N,01131.001,E,1,08,0.9,545.5,M,46.9,M,,*48 ... (continues every second)

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Common Pitfalls

Wrong serial port: Raspberry Pi uses /dev/serial0 or /dev/ttyAMA0 for UART; check which one your Pi uses.
Serial interface disabled: Enable UART in Raspberry Pi configuration using raspi-config.
Conflicts with Bluetooth: On some Pi models, Bluetooth uses UART; disable Bluetooth or use a USB GPS module.
Incorrect baud rate: Most GPS modules use 9600 baud; verify your module's specs.
Parsing errors: GPS data is in NMEA format; use libraries or carefully parse strings.

python

## Wrong way: Using wrong serial port or baud rate
import serial
ser = serial.Serial('/dev/ttyUSB0', 4800)  # Wrong port and baud rate

# Right way:
ser = serial.Serial('/dev/serial0', 9600)

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Quick Reference

Summary tips for using GPS module with Raspberry Pi:

Connect GPS TX to Pi RX (GPIO15), GPS RX to Pi TX (GPIO14).
Enable UART via sudo raspi-config > Interface Options > Serial.
Use /dev/serial0 as the serial port in code.
Set baud rate to 9600 unless your GPS module specifies otherwise.
Parse NMEA sentences like $GPGGA for location data.

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Key Takeaways

Connect GPS module TX/RX pins correctly to Raspberry Pi UART pins and enable UART interface.

Use Python's serial library to read GPS NMEA sentences from /dev/serial0 at 9600 baud.

Parse NMEA sentences like $GPGGA to extract useful GPS data such as latitude and longitude.

Check and disable Bluetooth if it conflicts with UART on Raspberry Pi models with built-in Bluetooth.

Always verify the correct serial port and baud rate to avoid connection issues.