Offline Automation

My projects are for greenhouse and irrigation in rural area so Internet connectivity.
We use ESP32 T-Call and RPI with 2G Modem.

Thus we required Automation(at least partially) which can work even if the connection is down or interrupted. I think to be fully automated for cross devices are not possible.

The following task required to run locally:

  1. timer/scheduling
  2. Relay trigger based on sensor input

Any suggestion to get this done?


Are you using deep sleep on the ESP32?


Yes, our controller need to check the sensor data every 5 minutes, we have around 8 sensors
It also includes 4 relays and also serve as controller for another 8 relay connected to it thru Tasmota.

And where does the RPI fit into the equation?
What’s is it’s role, and what software are you running on it?


we have two type of system which we plan to add Blynk for remote control. EsP32 for hydroponics and small aquaculture. RPi for greenhouse

It’s difficult to provide any sensible guidance if you just provide small snippets of random information.


Hey there. I think you should try this :

  Download latest Blynk library here:
  Blynk is a platform with iOS and Android apps to control
  Arduino, Raspberry Pi and the likes over the Internet.
  You can easily build graphic interfaces for all your
  projects by simply dragging and dropping widgets.
    Downloads, docs, tutorials:
    Sketch generator: 
    Blynk community:  
    Follow us:        
  Blynk library is licensed under MIT license
  This example code is in public domain.
  This example shows how to keep WiFi connection on ESP8266.

/* Comment this out to disable prints and save space */
#define BLYNK_PRINT Serial

/* Fill-in your Template ID (only if using Blynk.Cloud) */
//#define BLYNK_TEMPLATE_ID   "YourTemplateID"

#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "YourAuthToken";

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "YourNetworkName";
char pass[] = "YourPassword";

int lastConnectionAttempt = millis();
int connectionDelay = 5000; // try to reconnect every 5 seconds

void setup()
  // Debug console

  Blynk.begin(auth, ssid, pass);

void loop()
  // check WiFi connection:
  if (WiFi.status() != WL_CONNECTED)
    // (optional) "offline" part of code

    // check delay:
    if (millis() - lastConnectionAttempt >= connectionDelay)
      lastConnectionAttempt = millis();

      // attempt to connect to Wifi network:
      if (pass && strlen(pass))
        WiFi.begin((char*)ssid, (char*)pass);