APRS and Messaging with LoRa
We use APRS tracking to help keep volunteers safe in major events. Members need to carry VECTOR radios to do so. What if we could give members small trackers and let you use your own radio?
A small, low-power tracker may make our civic events work easier. LoRa (Long Range) is a proprietary modulation that uses chirp spread spectrum to achieve long ranges with low power use and high immunity to interference. We intend to use the 433 MHz version to test APRS, telemetry, and short messaging.
We need two to four people to help field test mini-trackers in June and July. Anthony VE7XAK has offered to lead the project and set up all the gear.
- Compare range between LoRa 433 MHz at 0.1 W and APRS 144 MHz at 5 W
- Transfer messages between smart phones connected across a LoRa mesh network
- Observe how varying the modulation and power impacts data transfer range and quality
Field Actions Over 4 to 8 Weeks
- Host two VECTOR IGates (Northeast Vancouver and West Side)
- Visit DSAs and travel city, noting tracker position and which IGate received your position
- Configure or reset components on an ESP32 board (bonus skill)
- Conduct a coordinated weekend exercise to test message ranges
Email Anthony to help evaluate this potential equipment.
Follow-up Notes and Links
Development circuit boards are getting mature after several years
- Recent LoRa designs include: WiFi, Bluetooth, GPS
- Multiple bands available, with one (433 MHz) aligning with amateur radio in Canada
- Existing 70 cm band antennas suit this trial
Open source firmware makes these boards readily configurable (Maker community)
- 6 TTGO T-Beam ESP32 boards with LoRa, WiFi, Bluetooth, GPS, OLED, Li-ion cell
- roof tripod antenna with feedline for West Side IGate
- vehicle-mounted external antenna for a mobile tracker
- Open source firmware from github.com for APRS (IGate and tracker) and messaging services
- Integrated Development Environment such as PlatformIO in Visual Studio Code for flashing and configuring the T-Beams