How to Connect the EByte E108-GN03D GPS Module to the EByte EoRa-S3 Board

This tutorial provides a detailed, step-by-step guide to connect the EByte E108-GN03D GPS module to the EByte EoRa-S3 development board with Meshtastic firmware. By the end of this guide, your GPS module will deliver location data (latitude, longitude, and altitude) to be displayed on the OLED screen of your Meshtastic device.

Step 1: Reference Documents

Before you begin, it’s essential to have access to the datasheets and schematics of the GPS module and development board to understand their pin configurations and connections. Below are the relevant links:

1. EByte E108-GN03D GPS Module Datasheet: Download Here
2. EByte EoRa-S3 Development Board Datasheet: Download Here
3. EByte EoRa-S3 Development Board Schematics: Download Here

These documents are crucial for verifying pinouts, wiring connections, and voltage requirements.

Step 2: Verify Wire Colors and GPS Pinout

Before connecting the GPS module to your EoRa-S3 board, double-check the wire colors and pin mapping of your GPS module. Merchants may use different color sequences for wires, so never assume wire colors match the provided examples without verification. Cross-reference the datasheet or consult your supplier for accurate information.

Here is the E108-GN03D GPS pinout for reference:

Step 3: Connect the GPS Module to the EoRa-S3 Board

The wiring involves connecting the GPS module pins to GPIO pins on the EoRa-S3 board. The GPIO pins used in this tutorial are just examples that work for this setup. Feel free to use other GPIO pins if they are more convenient for your application. Be sure to enter the correct GPIO assignments in the Meshtastic settings later.

Here is an example:

The following Mermaid diagram shows the wiring connections between the GPS module and the EoRa-S3 board:

flowchart TD

    %% GPS Module Pins
    GPS_ON_OFF["ON_OFF (White)"]
    GPS_1PPS["1PPS (Blue)"]
    GPS_GND["GND (Green)"]
    GPS_TXD["TXD (Yellow)"]
    GPS_RXD["RXD (Black)"]
    GPS_VCC["VCC (Red)"]

    %% EoRa-S3 Pins
    EORA_IO37["IO37 (GPIO for power control)"]
    EORA_GND["GND"]
    EORA_IO16["IO16 (RX)"]
    EORA_IO15["IO15 (TX)"]
    EORA_5V["5V / 3.3V"]

    %% Not Applicable Node
    NotApplicable["Not applicable for Meshtastic"]

    %% Connections with wire colors
    GPS_ON_OFF ---|White| EORA_IO37
    GPS_GND ---|Green| EORA_GND
    GPS_TXD ---|Yellow| EORA_IO16
    GPS_RXD ---|Black| EORA_IO15
    GPS_VCC ---|Red| EORA_5V
    GPS_1PPS ---|Blue| NotApplicable

    %% Style for NotApplicable node
    classDef notconnected fill:none,stroke-dasharray:3 3,stroke:#000;
    class NotApplicable notconnected;

Notes:

• Double-check the wire colors and GPS pinouts.
• Ensure VCC and GND connections are correct to avoid damaging the GPS module.

Step 4: Configuring Meshtastic Firmware

After connecting the hardware, you need to configure the Meshtastic firmware to use the correct GPIO pins for the GPS module.

1. Open the Meshtastic Web UI or connect using the Meshtastic app.
2. Go to the GPS module configuration section.
3. Assign the GPIO pins for RX, TX, and Enable:
   • Receive Pin (RX): Set to 16 (connected to the GPS module’s TXD pin).
   • Transmit Pin (TX): Set to 15 (connected to the GPS module’s RXD pin).
   • Enable Pin: Set to 37 (connected to the GPS module’s ON_OFF pin).
4. Save the configuration and restart the device.

Notes:

• You can use different GPIO pins as long as they are specified correctly in the Meshtastic settings.
• The 1PPS pin does not need to be connected for Meshtastic to work.

Step 5: Testing the GPS Connection

After wiring and configuring the firmware, test the GPS module to ensure it is working correctly.

Steps:

1. Power on the EoRa-S3 board.
2. Wait for the GPS module to acquire satellites. This may take up to a few minutes, depending on the location and sky visibility.
3. Check the OLED screen on the Meshtastic device:
   • Latitude and Longitude: Verify that the device displays coordinates like 37.7749 and -122.4194.
   • Altitude: Verify the altitude reading (e.g., 50.3 m).

Debugging:

If the GPS data is not displayed:

1. Recheck the wiring connections, especially the TX and RX lines.
2. Verify that the GPIO pins in the Meshtastic settings match your wiring.

Practical Applications

With the GPS module connected, the Meshtastic device can now:

1. Share your real-time location with other Meshtastic users.
2. Display altitude, latitude, and longitude on the OLED screen.
3. Use the location data for navigation, tracking, and outdoor activities.
4. Update device time RTC.

Conclusion

This tutorial demonstrated how to connect and configure the EByte E108-GN03D GPS module with the EByte EoRa-S3 board running Meshtastic firmware. By carefully checking the wiring and configuring the firmware, your Meshtastic device can now effectively use GPS data for enhanced functionality. Always double-check wire colors and pin mappings, and feel free to use different GPIO pins as per your setup requirements.

If you encounter any issues or want to expand the functionality, feel free to reach out for further assistance!