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.
- 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.
The in-development apps are secure chat and community resource mapping (an offline map that communities can use to add resources, like tidepools).
- Bandwidth: < 2000 kbits/sec.
- Power: Nodes need at minimum a 6V, 3W solar panel plus a battery capable of 3600mAh
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](https://www.tvc-mall.com/details/3w-6v-diy-monocrystalline-silicon-solar-panel-145mm-x-145mm-sku85020025a.html?c=USD&utm_source=google&utm_medium=pla&utm_campaign=cse&gclid=Cj0KCQjwm9vPBRCQARIsABAIQYfM_ndtJ1RmWUGdkqA8Um40bBY9H3kJ9xRg6gLKMoaC65sB17ZRiJ4aAhHdEALw_wcB) - $3
- Solar Panel - 6V, 3W, 120mAH - [another lead](https://www.tvc-mall.com/details/3w-6v-diy-monocrystalline-silicon-solar-panel-145mm-x-145mm-sku85020025a.html) - $5-6
- LiOn Battery - 3.7V 3600mAh - $4
- LTO battery? - NEED TO RESEARCH COSTS
- 3.3V buck converter - $5
- Enclosure - ~$5
* Total: ~$40
- 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/
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.