This Low-Cost ESP8266 LoRa Gateway Gives Your Smartphone Text Chat Support Even While Off-Grid
Pseudonymous electronics engineer "Keegan" has put together a handy tool for off-grid communications: A LoRa gateway, which provides smartphones with group chat facilities via Wi-Fi, at ranges of up to 10km (around 6.2 miles) between units.
"I started this project because I often travel in convoy with friends to remote areas where sending a simple WhatsApp message is impossible due to non-existent cell phone signal," Keegan explains. "This makes it difficult to let friends know which turn to take or when we are stopping for a break without them being able to physically see us take a turn or pull over."
The solution: an Espresssif ESP8266-based gadget that uses a Semtech SX1278 LoRa transceiver for long-range low-power communication. The compact gateway provides support for up to eight smartphones, and sends messages from each to linked gateway devices — which can be up to 10km (around 6.2 miles) apart — and on to other smartphone devices.
"This solution isn't just applicable to road trips," Keegan notes, "but any situation where long distance communication is necessary as it is small, light weight and low power."
Current in the proof-of-concept stage — responsible for the limit of eight devices per gateway — the prototype gateway is built on perf-board housed in a 3D printed case with an SMA connector for an external antenna, as well as a 5V USB input for power.
"The plan is to later build a custom PCB to reduce the device footprint," Keegan writes, "as well as [to] add additional features such as a charging controller for LiPo batteries and then enclose it in a water resistant case. Currently I have only developed an app for Android, this app is still in early stages and for now just serves as a POC. Improvements to UI and additional features will be added in the future as well as the possibility for iOS support."
More information is available on the project's Hackaday.io page, while the source code for the base station and companion app are both published to GitHub under the reciprocal GNU General Public License 3.