dmd docs
LoRa
Long-Range Group Communication for DMD Devices
The LoRa app enables long-range wireless communication between riders in a DMD2 Riding Group. It connects to the device's built-in or plug-in LoRa module, allowing riders to share their location and send text messages without relying on mobile data or internet connectivity.
Quick Info
- Access
- Via Manage App
- Requires
- DMD device with LoRa module
- Type
- System App (pre-installed)
- Range
- Up to 10-15 km (line of sight)
Table of Contents
Overview
LoRa (Long Range) is a radio technology designed for low-power, long-distance communication. The DMD LoRa app uses this technology to create a direct radio link between riders in the same DMD2 Riding Group — no SIM card, no mobile data, no internet required.
Location Sharing
Share your GPS position, speed, and status with your group over LoRa radio — visible on every rider's map in DMD2.
Group Chat
Send and receive text messages to your group directly over LoRa — no internet needed.
Mesh Relay
Packets are automatically relayed through other riders in the group to extend range beyond direct line of sight.
Getting Started
Setting up LoRa communication is straightforward — no pairing or manual frequency configuration required.
Launch it via the Manage App. You'll see the module status and a toggle switch.
Toggle the switch to ON. The app will connect to the hardware module and show a green status dot when connected.
Go to DMD2 and create a group or join an existing one. DMD2 will automatically configure the LoRa frequency based on your GPS region.
Your location is automatically shared with your group over LoRa. Other riders with LoRa enabled will appear on your DMD2 map, even without internet.
Rider Location Sharing
When LoRa is active and you're in a DMD2 Riding Group, the app continuously broadcasts your position over radio:
What is shared
- GPS location (latitude and longitude)
- Speed (current speed in km/h)
- Status flags — sharing active, needs help, internet available, LoRa available
- Timestamp — when the data was captured
What you see on the map
In DMD2, each rider in your group appears on the map with their current position. Riders connected via LoRa show a LoRa icon next to their name. If a rider also has internet, both icons are visible. The app also shows an "SOS / Help Me" indicator if a group member has triggered the SOS system.
LoRa vs Internet
LoRa works alongside internet-based group sharing. When both are available, DMD2 uses whichever provides the most recent data. LoRa is essential for remote areas where mobile coverage is unavailable — mountains, forests, deserts, and backcountry trails.
Group Chat
The LoRa app includes a built-in group chat that works entirely over radio.
Sending Messages
Open the LoRa app, type your message in the chat box at the bottom, and tap the send button. Messages are transmitted immediately over LoRa to all group members within range.
Receiving Messages
Incoming messages appear in the chat area with the sender's name and timestamp. Your own messages are shown on the right (blue), others on the left (dark).
Regions & Frequencies
The LoRa app automatically selects the correct frequency band based on your GPS location. Different countries require different radio frequencies to comply with local regulations.
| Region | Frequency | Countries |
|---|---|---|
| EU868 | 868 MHz | Europe, UK, Middle East, Africa |
| US915 | 915 MHz | United States, Canada |
| AU915 | 915 MHz | Australia, New Zealand |
| BR915 | 915 MHz | Brazil, South America |
| IN865 | 865 MHz | India |
| JP920 | 920 MHz | Japan, South Korea |
| RU864 | 868 MHz | Russia |
App Screen
The LoRa app has a single screen divided into sections:
- Module Status (top)
- Shows connection status (green/red dot), firmware version, current channel and frequency, and the detected region.
- LoRa Toggle (top right)
- Turns the LoRa module on or off. The setting is remembered across restarts.
- Riding Group (bottom left)
- Shows the current group name, rider count, and a list of all riders with their display name, speed, connection icons (internet/LoRa), and time since last update.
- Group Chat (bottom right)
- Shows chat message history and a text input field with send button for composing messages.
Background Service
While LoRa is enabled, a background service runs to maintain the radio connection:
LoRa service running
This notification is required by Android for background services. The service continues transmitting and receiving even when you switch to DMD2 or other apps. It starts automatically at boot if previously enabled.
Troubleshooting
- Make sure the LoRa toggle is ON.
- Try toggling it OFF and ON again.
- Restart the device if the module fails to initialize.
- Not all DMD devices include a LoRa module — check your device specifications.
- Make sure both you and the other riders have LoRa enabled and connected (green dot).
- You must all be in the same DMD2 Riding Group.
- Check that DMD2 is running in the foreground — your own data only updates when DMD2 is active.
- LoRa range is up to 10-15 km line of sight, but can be reduced by terrain, buildings, and vegetation.
- Verify both devices show a green connection dot.
- LoRa is half-duplex — it cannot send and receive simultaneously. Messages may be briefly delayed.
- If riders are too far apart, messages may not reach. The mesh relay feature can help extend range when 3 or more riders are in the group.
The LoRa module transmits at up to 30 dBm (1 Watt). Typical range:
- Open/flat terrain: 10-15 km
- Hilly/mountainous: 3-8 km (depending on line of sight)
- Urban/forest: 1-5 km
The mesh relay feature (enabled when 3+ riders are in the group) allows packets to hop through intermediate riders, effectively extending coverage beyond direct range.