DisasterRadio
Introduction
DisasterRadio is an off-grid (solar-powered) low-bandwidth long-range mesh network built on free and open source software and affordable open hardware.
The nodes are small and entirely self-contained units that can be deployed simply by leaving them in a place with sun. They are intended for either manual or drone-deployment on rooftops or in windows. They use high gain omni-directional antennas on 915 MHz using the LoRa PHY (Chirp Spread Spectrum) to talk to each-other and a downward-pointing/inward-pointing high gain wifi antenna to talk to user devices (phones/tables/laptops) inside the buildings on which they are placed. They use a low-power microcontroller running a web server that lets anyone use the network as long as they have a device with wifi and a web-browser.
Updates
- Status as of 31 October 2017: User:nanomonkey and fritz received the custom PCB boards they designed. got one working tonight \o/
- Status as of June 10th 2017: Basic chat between two nodes working. A more fleshed-out website should appear here soon.
Applications
The in-development apps are secure chat and community resource mapping (an offline map that communities can use to add resources, like tidepools).
Technical Specifications
- Bandwidth: < 2000 kbits/sec.
- Power: Nodes need at minimum a 6V, 3W solar panel plus a battery capable of 3600mAh
Components
All are initial estimations, probably missing a component or two and haven't scoured for bulk prices on everything Tunabananas:
- ESP8266 - $2.50
- LoRa Transceiver - HackRF RFM95W - $7 OR [Dorji DRF1276G](https://www.tindie.com/products/DORJI_COM/868mhz-915mhz-sx1276-module-drf1276g/) - $6
- Custom PCB - ~180x120, 1 layer, 100ct - $6.50
- Directional WiFi Antenna 5dBi - another option - $3
- Solar Panel - 6V, 3W, 120mAH - another lead - $5-6
- LiOn Battery - 3.7V 3600mAh - $4
OR
- LTO battery? - NEED TO RESEARCH COSTS
- 3.3V buck converter - $5
- Enclosure - ~$5
* Total: ~$40
Documentation
- Code is here: https://github.com/sudomesh/disaster-radio-nodemcu
- Documentation wiki is here: https://github.com/sudomesh/disaster-radio/wiki
- Network visualization simulation: https://jemucino.github.io/disaster-radio-netsim/
Presentations
juul gave a talk about this at the 2017 BATTLEMESH in Vienna. Slides
User Research
Tunabananas designed use cases and user stories for the decentralized mobile mapping application Tidepools in early 2013, based on open-ended interviews with community residents and various organizations engaged in technology equity and access.