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IoT Home Automation | Basic plant watering system

Almost 3 months past without working on the own IoT home solution. In the meantime, I was able to lose the UI implementation. Because of this in the next 1-2 weeks, I will try to rewrite it.
The previous post about my IoT solution: IoT Home Automation | Stabilize the garage doors solution after power break (resistors and capacitors)

Because summer holidays are here and I didn't want to bother my neighbors to water the flowers I decided to come up with a fast and cheap solution based on ESP8266. For grass I already have an automation solution from Gardena, but if you can do it yourself why not. Especially if you take into account the price of Gardena controller.

The first version is pretty basic, from the features perspective. No internet connection, no reporting, no humidity sensors and other stuff like this. Lack of time forced me to keep things super necessary, but I've replicated 100% the Gardena controller with less than 10 euros.
The pipes and connectors are another stories from the cost perspective, but you cannot avoid this. I highly recommend to use high-quality water tube connectors.
I just added a timer and every 12 hours I open different water circuits for 4 minutes or 30 seconds.

#include <Arduino.h>
#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <time.h>

#ifdef ESP8266
extern "C" {
#include "user_interface.h"

#define DEFAULT_TIME_MS_1 4*60*1000
#define DEFAULT_TIME_MS_2   30*1000

void setup() {
  pinMode(D1, OUTPUT);
  pinMode(D3, OUTPUT);
  // This is required to read ADC values reliably
  // Delay is required only for debugging
  Serial.println("Setup complete");
void loop() {
  Serial.println("Open Valve 1:");
  triggerValve(1, DEFAULT_TIME_MS_1);
  Serial.println("Close Valve 1:");

  Serial.println("Open Valve 2:");
  triggerValve(2, DEFAULT_TIME_MS_2);
  Serial.println("Close Valve 2:");

  Serial.println("Sleep for the next 12h");

void triggerValve(int gateNumber, int openDuration){
  Serial.println("Open Relay"); 
  digitalWrite(D(gateNumber), HIGH);    
  Serial.println("Close Relay");
  digitalWrite(D(gateNumber), LOW);    

uint8_t D(uint8_t index) {
  switch (index) {
    case 1: return D1;
    case 2: return D3;
As you can see, I reset the ESP8266 every 12h automatically. This is something temporary until I'm able to connect to the internet and add some new features.
As you can see the code is super simple, in the lack of time and a UI for my previous solution, I kept things pretty simple. Most of the time was invested in the hardware part - especially water tubes.
Once I recreate the UI, I want to be able to push custom time intervals to the controller and to be able to add reporting capabilities.
Even if I have some humidity sensors, I am not interested to integrate them, especially because I would need around 4 different sensors and the idea of having too many cables is not so appealing for me.


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