Plant watering system

 During the summer, we usually go sailing for 3-5 weeks, and in this time our indoor plants need water ( or at least that's the story, in reality I just found the idea funny to play around with).

Again the Arduino Nano was my place to go to, this time a Arduino Nano Every, a little DC motor(wrs-385sa) with a Peristaltic pump, from something I disassembled long time ago, and a dual relay board.

The fist little mockup looked like this:

The sensor I used was the common available. The one used was a Chinese brand, but is is pretty much the same as the one SparkFun has.

After about a week of testing and coding, the values I was reading started to drift, and I use at least 2 days of debugging, before I - mostly by accident, had a look at the sensor.
The metal on one of the electrodes was basically gone, so here was my problem.

If you need something that should work more than a couple of days, I can recommend using a capacitive soil moisture sensor instead, like the one one below, it is a bit more expensive (~ 6 Euro @ arduino.cc), but worth it.
After a few months of constant use, it still works like a charm:

After the code was done, and the hardware stated to turn out as I wanted it to, next step was to transform it to something 'I would be able to look at every day, and one thing was, I would only use one relay, and I would like to get the breadboard out of the way, so i started to draw this:

It basically ended out as a more generic controlboard, that later on could be used for a hydroponics project as well( and proberly a lot of other stuff, )

As seen on the picture below, I opted for smd components, for the version below.

  

A new version of the PCB is in the making , the main difference is that the smd components is gone and replaced by ordinary components, and instead of pins for one sensor, the new board har pins for 3 sensors, in order to take into account if the canister where the water is drained from is empty and a sensor to detect a overflow on the plant. I also added 2 LED's, again I see this board as a easy small generic project board, that I hope to reuse for other stuff as well.

..To be continued..

Note: the plant used is Ginger ;)

Arduino Code:

// Sense moisture in soil, and start pump(relay) to water the plant if needed.
// https://wiki.dfrobot.com/Capacitive_Soil_Moisture_Sensor_SKU_SEN0193

char newstate[5][5][10] = {
                    {"1", "Soaked", "0", "271", "3600000"}, // 60 min. Water
                    {"2", "Moist", "271", "350" ,"1800000"}, // 30 min. Wet
                    {"3", "Damp", "351", "430", "900000" }, // 15 min. // 450 Damp
                    {"4", "Dry ",  "431", "520", "300000" }, // 5 min. Dry
                    {"5", "Very dry", "521", "1024","120000" }}; // 2 min. Air
// ----- Sleeptime vs level ------------
       //delay(120000); // 2 min. / 5
       //delay(300000); // 5 min. / 4
       //delay(900000); // 15 min. / 3
       //delay(1800000); // 30 min. 7 2
       //delay(3600000); // 60 min. / 1
//--------------------------------------
int soilpin = A4; // sensor1
int tankempty = A3; // sensor2
int tankmyoverflow = A2; // sensor3
int RELAY1 = 21; // was 3
int LED1 = 4;
int LED2 = 5;

void setup() {
  Serial.begin(9600);
  Serial.println("Startup");
  Serial.println("Message,value,level,sleeptimer,myoverflow,empty");
  pinMode(13, OUTPUT); // Buildin LED
  pinMode(LED1, OUTPUT); // Buildin LEDa
  pinMode(LED2, OUTPUT); // Buildin LED
  pinMode(RELAY1, OUTPUT); // Relæ 1
  pinMode(tankmyoverflow, INPUT); // myoverflow sensor
  pinMode(tankempty, INPUT); // Empty sensor
  digitalWrite(RELAY1, LOW); // Relæ 1
}
void showlevel(String level){
    for ( int i = 0; i < level.toInt(); ++i ) {
      digitalWrite(13, HIGH); 
            digitalWrite(LED1, HIGH); 
      delay(500);
      digitalWrite(13, LOW);
            digitalWrite(LED1, LOW); 
      delay(500);
    }
}

void loop() {
  //Serial.println("Starting loop");
  digitalWrite(13, HIGH); 
  int a; int sleeptime=0; int val=0; int empty=0;int myoverflow=0; String level;String thismin;String thismax;String sleeptimer;// init control signals
  char message[15];
  val = analogRead(soilpin);
  myoverflow = analogRead(tankmyoverflow);
  empty = analogRead(tankempty);
  for ( int i = 0; i < 5; ++i ) {
    thismin= newstate[i][2];
    thismax= newstate[i][3];
      if (val >= thismin.toInt() && val <= thismax.toInt()) {
        a=i;
        level= (newstate[i][0]);
        sleeptimer= (newstate[i][4]);
      } 
  }

  if (empty < 800 && myoverflow < 800) {
         if ( level.toInt() >= 4) 
            {
              Serial.println("Pump ON");
              digitalWrite(RELAY1, HIGH);  
              digitalWrite(LED1, HIGH);
              delay(3000);  
              Serial.println("Pump OFF");
              digitalWrite(RELAY1, LOW);    
              digitalWrite(LED1, LOW);
            }
  }
  strncpy(message, newstate[a][1], sizeof (message));
  if (empty > 700 || myoverflow > 700) {
    char message[25] = "Tank Empty or overflow";
    digitalWrite(LED2, HIGH);
  }
  else {
    digitalWrite(LED2, LOW);
  }  
 
  // Print data to console
  Serial.print(message);
  Serial.print(",");
  Serial.print(val);
  Serial.print(",");
  Serial.print(level);
  Serial.print(",");
  Serial.print(sleeptimer);
  Serial.print(",");
  Serial.print(myoverflow);
  Serial.print(",");
  Serial.println(empty);
  //showlevel(level); // flash LED1 a number of times to indicate current level 
 delay(sleeptimer.toInt()); // sleep x time according to current level

}