LilyGO T-Beam

The LilyGO T-Beam (Classic version) is a mobile-focused IoT development board that combines an ESP32 microcontroller, a Semtech SX1276 LoRa transceiver, and an integrated GPS module on a single PCB.

While originally designed for GPS + LoRa tracking projects, it has become one of the most widely used portable devices for running Meshtastic firmware.

In our mesh architecture, the T-Beam serves as a mobile scout node — a battery-powered field device used for position reporting, range testing, and active participation in the mesh network.

Core Specs

Processor & Memory

The ESP32 provides enough processing power to:

• Run Meshtastic networking logic
• Parse and transmit GPS coordinates
• Provide Bluetooth configuration
• Maintain mesh participation

While not as modern as the ESP32-S3 found in newer boards, the Classic ESP32 remains fully supported and stable under Meshtastic firmware.

LoRa Radio Features

The SX1276 transceiver is an older-generation but widely proven LoRa chip. Under Meshtastic:

• It supports regional frequency plans.
• It allows tuning of bandwidth, spreading factor, and coding rate.
• It provides reliable long-range communication when paired with a proper antenna.

The ~20 dBm transmit power is typical for this chipset. Real-world range depends heavily on antenna gain, height, terrain, and interference - not just transmit power.

GPS Integration

Unlike many smaller nodes, the T-Beam includes onboard GPS hardware.

This allows:

• Automatic position reporting
• Smart position updates (movement-based broadcasting)
• Distance-based throttling of GPS messages
• Mobile coverage testing

In our setup, GPS is enabled so the T-Beam can act as a moving probe inside the network.

Antenna & Wireless Configuration

The T-Beam uses a full-size SMA connector for the LoRa antenna, which simplifies upgrades.

This means:

• No U.FL pigtail is required (unlike the Heltec V3).
• Standard SMA LoRa antennas can be attached directly.
• Higher-gain antennas can be tested easily for range experiments.

We typically run the T-Beam with a tuned 915 MHz antenna suitable for mobile operation rather than high-gain fixed deployment.

Role in Our Mesh Architecture

λlambda-base, LBAS (Heltec V3)

• Fixed location
• USB powered
• MQTT enabled
• Acts as data bridge and backbone node

stepweaver.dev, SWDV (T-Beam Classic)

• Battery powered
• GPS enabled
• Mobile participant
• Range and coverage probe

This separation prevents role overlap and creates a clean architecture:

• Base node = stability and data aggregation
• Scout node = mobility and network exploration