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LoRa Modules

Radio modules used in the mesh network.

Heltec ESP32 LoRa V3​

Main module connected to the Raspberry Pi gateway.

Specifications​

ComponentDetails
MCUESP32-S3
LoRaSX1262
Frequency915 MHz (US)
InterfaceUSB-C
AntennaExternal SMA

Connection to RPi5​

Heltec ESP32 LoRa V3 ←→ USB-C ←→ Raspberry Pi 5

The module appears as /dev/ttyUSB0 or /dev/ttyACM0.

Verify connection​

# List USB devices
lsusb

# Check serial ports
ls -la /dev/ttyUSB* /dev/ttyACM*

# Get Meshtastic info
meshtastic --info

Firmware​

Pre-flashed with Meshtastic firmware. To update:

# Download latest firmware from meshtastic.org
# Use esptool or web flasher

SX1262 Module​

The SX1262 is the LoRa transceiver chip used in both:

  • Heltec ESP32 LoRa V3
  • T1000-E Trackers

Specifications​

ParameterValue
Frequency150-960 MHz
ModulationLoRa / FSK
Max power+22 dBm
Sensitivity-148 dBm
RangeUp to 15km (line of sight)

Antenna Considerations​

Gateway antenna​

  • Use external antenna for best range
  • Mount as high as possible
  • Avoid obstructions

Tracker antennas​

  • Internal antenna (built-in)
  • Orientation affects performance
  • Keep away from body when transmitting

Known Issues​

WIO-SX1262 Module (Defective)​

warning

The tested WIO-SX1262 module from Seeed Studio has communication problems and should NOT be used.

Symptoms:

  • Not detected correctly
  • Intermittent communication errors
  • Firmware won't flash

Solution: Use Heltec ESP32 LoRa V3 instead.

Frequency Planning​

US Region (915 MHz)​

ChannelFrequency
0902.0 MHz
1906.0 MHz
......
Default906.875 MHz

All devices must use the same region setting.