Building out project involving multiple ESP32 (WROOM) outdoor devices equipped with GPS and IMU on mesh network. ESP32 stats that with ‘painless mesh’ and esp-mesh, roughly 500-1000ft should be possible. However am wanting to design mesh network to work primarily in offline ad-hoc setup where data is not tied to cloud network.
Already know that Blynk is designed to function using cloud but is following setup possible?
User would have iOS, Android device on phone and would access esp32 devices via bluetooth to view realtime data. Would use mqtt on devices so each device knows where other is. On push request the app would download this data to see history of where device has been over time period. Other data would be available including gps, imu, pressure and temperature for example.
Ideal case study for this would be monitoring outdoors users within outdoor area. With mesh setup distance can be extended greater. With bluetooth setup, I would only need to access one of esp32 devices on network. Time period for monitoring devices would be typically several hours in single day.
Other usage would be to connect one of devices to cloud as gateway which is typical setup for Blynk devices. With each device being solar powered, can expect to deploy as long term iot outdoor sensor.
Should this possible? Am also exploring another option of simply building app using Flutter which allow for offline function ability without cloud.
I think that to achieve this you’d need a constantly powered MQTT broker. If you were going down that route then you’d be better pushing the data tothe Blynk cloud from this device.
Thanks for feedback. Another component am exploring for project is having an additional device tied to esp32’s but as touchscreen with Rasp Pi 4. Should this too be able to work communicating via mqtt? Forgot to mention that phone apps would include google map widget labeling location of devices and their corresponding data. Could satellite maps be cached on phone in case of disruption in cellular service (similar to how Navit can download maps for offline use)? Could this also be done on Pi4? Exploring if data could be shown on browser (set to full screen) on Pi while running locally. Pi would also be run in offline mode with limited cloud with network communication by mqtt.
I’m not sure if this is gonna be helpful for you or not but it’s worth a try, you can run Node-RED on the raspberry pi and use MQTT communication protocol to communicate with your devices.
If you can find a way to have your Pi permanently powered (and remember that they require quite a lot of power, and that the touch screen adds to this) then it could be your MQTT broker.
If the Pi could have a permanent network connection, maybe via a cellular modem, then it could also talk to the Blynk cloud servers via Node-Red and the Blynk plug-in for Node-Red.
Otherwise, I don’t see how this setup could work effectively. Maybe you ought to do some field trials with the hardware you’re thinking of using, to prove some of the basic principals that you’ve discussed so far, as I have my doubts about many of the ideas that you’ve floated.