plant_moisture_sensor.ino

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>

int val = 0; // moisture value 
int soilPin = A0;
byte host[] = {192, 168, 11, 17}; //influxdb host
int port = 8089; //influxdb port
int soilPower = 5;//Variable for Soil moisture Power
int sleepTime = 1800;//seconds
#define WLAN_SSID       "fu"
#define WLAN_PASS       "bar"

WiFiUDP udp;

void setup_wifi() {
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.print(WLAN_SSID);

  WiFi.begin(WLAN_SSID, WLAN_PASS);

  WiFi.persistent(false);
  WiFi.mode(WIFI_OFF);
  WiFi.mode(WIFI_STA);
  WiFi.begin(WLAN_SSID, WLAN_PASS);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.print("WiFi connected: ");
  Serial.println(WiFi.localIP());
}

void setup() {
  Serial.begin(115200);
  pinMode(soilPower, OUTPUT);
  digitalWrite(soilPower, LOW);//Set to LOW so no power is flowing through the sensor by default
  setup_wifi();
}

void loop() {
  String soil, line;
  int v;

  v = readSoil();
  Serial.println(v);
  v = map(v, 90, 361, 0, 10);//calibrated values
  soil = String(v);
  //https://docs.influxdata.com/influxdb/v1.5/write_protocols/line_protocol_tutorial/
  line = String("environment,location=plant_1 soil=" + soil + "i");
  Serial.println(line);

  //send line to influxdb
  udp.beginPacket(host, port);
  udp.print(line);
  udp.endPacket();
  delay(1000);

  Serial.println("Going to a deep sleep...");
  ESP.deepSleep(sleepTime * 1000000);
}
int readSoil(){
  digitalWrite(soilPower, HIGH);
  delay(10);
  val = analogRead(soilPin);
  digitalWrite(soilPower, LOW);
  return val;
}