New Project: G3H

It is time for a new project! As you may have guessed from the (rather old) previous posts, I like the arduino and I love growing plants, fruits and vegetables. I am a relative beginner in both fields.

And in learning both fields more or less simultaneously, I came up with an idea after reading Make Magazine 18. In that issue, a project is described that uses an arduino to monitor plants and water them automatically, as well as switch on growlights when the plants did not get enough light during the day.

Combined with some stuff I read on square foot gardening and a good offer on a small greenhouse I came up with the idea to build a small, soft of, square foot garden, add a greenhouse on top and control the whole thing with an arduino.

My brother-in-law heard about it on twitter (I am @ArnoJansen, though part of my tweets are in dutch) and called in a “Willy Wortel” invention. Willy Wortel is dutch for Gyro Gearloose, hence the working title for this project: Gyro Gearhead GreenHouse, or G3H in short.

I am currently building the garden box and the greenhouse and have started on setting up a prototype board with the arduino to measure light, temperature and soil humidity. I did take some pictures which I will share later.

For now, let me show you the sensor testcode as I currently have it in my Arduino IDE (it assumes the same setup as the garduino article in Make Magazine, although you may want to change pin-outs):

// Project: G3H Sensor Testcode
// Author: Garduino project, Make Magazine 18 / Modified by Arno Jansen
// Version: 0.1
// Date: April 7, 2010

//include the datetime library, so our garduino can keep track of how long the lights are on
#include <DateTime.h>

//define analog inputs to which we have connected our sensors
int moistureSensor = 0;
int lightSensor = 1;
int tempSensor = 2;

//define digital outputs to which we have connecte our relays (water and light) and LED (temperature)
int waterPump = 7;
int lightSwitch = 8;
int tempLed = 2;

//define variables to store moisture, light, and temperature values
int moisture_val;
int light_val;
int temp_val;

//decide how many hours of light your plants should get daily
float hours_light_daily_desired = 14;

//calculate desired hours of light total and supplemental daily based on above values
float proportion_to_light = hours_light_daily_desired / 24;
float seconds_light = 0;
float proportion_lit;

//setup a variable to store seconds since arduino switched on
float start_time;
float seconds_elapsed;
float seconds_elapsed_total;
float seconds_for_this_cycle;

void setup() {
//open serial port
Serial.begin(9600);
//set the water, light, and temperature pins as outputs that are turned off
pinMode (waterPump, OUTPUT);
pinMode (lightSwitch, OUTPUT);
pinMode (tempLed, OUTPUT);
digitalWrite (waterPump, LOW);
digitalWrite (lightSwitch, LOW);
digitalWrite (tempLed, LOW);

//establish start time
start_time = DateTime.now();
seconds_elapsed_total = 0;

}
void loop() {
// read the value from the moisture-sensing probes, print it to screen, and wait a second
moisture_val = analogRead(moistureSensor);
Serial.print(”moisture sensor reads “);
Serial.println( moisture_val );
//delay(1000);
// read the value from the photosensor, print it to screen, and wait a second
light_val = analogRead(lightSensor);
Serial.print(”light sensor reads “);
Serial.println( light_val );
//delay(1000);
// read the value from the temperature sensor, print it to screen, and wait a second
temp_val = analogRead(tempSensor);
Serial.print(”temp sensor reads “);
Serial.println( temp_val );
//delay(1000);
Serial.print(”seconds total = “);
Serial.println( seconds_elapsed_total );
//delay(1000);
Serial.print(”seconds lit = “);
Serial.println( seconds_light);
//delay(1000);
Serial.print(”proportion desired = “);
Serial.println( proportion_to_light);
//delay(1000);
Serial.print(”proportion achieved = “);
Serial.println( proportion_lit);
Serial.println();
Serial.println();
Serial.println();
Serial.println();
Serial.println();
Serial.println();
Serial.println();
Serial.println();
delay(1000);
//turn water on when soil is dry, and delay until soil is wet
//if (moisture_val < 850)
//{
//digitalWrite(waterPump, HIGH);
//}

//while (moisture_val < 850)
//{
//delay(10000);
//}

//digitalWrite(waterPump, LOW);

//update time, and increment seconds_light if the lights are on
seconds_for_this_cycle = DateTime.now() – seconds_elapsed_total;
seconds_elapsed_total = DateTime.now() – start_time;
if (light_val > 900)
{
seconds_light = seconds_light + seconds_for_this_cycle;
}

//cloudy days that get sunny again: turn lights back off if light_val exceeds 900. this works b/c the supplemental lights aren’t as bright as the sun:)
//if (light_val > 900)
//{
//digitalWrite (lightSwitch, LOW);
//}

//turn off lights if proportion_lit>proportion_to_light, and then wait 5 minutes
//if (proportion_lit > proportion_to_light)
//{
//digitalWrite (lightSwitch, LOW);
//delay (300000);
//}

//figure out what proportion of time lights have been on
//proportion_lit = seconds_light/seconds_elapsed_total;

//turn lights on if light_val is less than 900 and plants have light for less than desired proportion of time, then wait 10 seconds
//if (light_val < 900 and proportion_lit < proportion_to_light)
//{
//digitalWrite(lightSwitch, HIGH);
//delay(10000);
//}

//turn on temp alarm light if temp_val is less than 850 (approximately 50 degrees Fahrenheit)
if (temp_val < 850)
{
digitalWrite(tempLed, HIGH);
}
}

/
Project: G3H Sensor Testcode

// Author: Garduino project, Make Magazine 18 / Modified by Arno Jansen

// Version: 0.1

// Date: April 7, 2010

//include the datetime library, so our garduino can keep track of how long the lights are on

#include <DateTime.h>

//define analog inputs to which we have connected our sensors

int moistureSensor = 0;

int lightSensor = 1;

int tempSensor = 2;

//define digital outputs to which we have connecte our relays (water and light) and LED (temperature)

int waterPump = 7;

int lightSwitch = 8;

int tempLed = 2;

//define variables to store moisture, light, and temperature values

int moisture_val;

int light_val;

int temp_val;

//decide how many hours of light your plants should get daily

float hours_light_daily_desired = 14;

//calculate desired hours of light total and supplemental daily based on above values

float proportion_to_light = hours_light_daily_desired / 24;

float seconds_light = 0;

float proportion_lit;

//setup a variable to store seconds since arduino switched on

float start_time;

float seconds_elapsed;

float seconds_elapsed_total;

float seconds_for_this_cycle;

void setup() {

//open serial port

Serial.begin(9600);

//set the water, light, and temperature pins as outputs that are turned off

pinMode (waterPump, OUTPUT);

pinMode (lightSwitch, OUTPUT);

pinMode (tempLed, OUTPUT);

digitalWrite (waterPump, LOW);

digitalWrite (lightSwitch, LOW);

digitalWrite (tempLed, LOW);

//establish start time

start_time = DateTime.now();

seconds_elapsed_total = 0;

}

void loop() {

// read the value from the moisture-sensing probes, print it to screen, and wait a second

moisture_val = analogRead(moistureSensor);

Serial.print(”moisture sensor reads “);

Serial.println( moisture_val );

//delay(1000);

// read the value from the photosensor, print it to screen, and wait a second

light_val = analogRead(lightSensor);

Serial.print(”light sensor reads “);

Serial.println( light_val );

//delay(1000);

// read the value from the temperature sensor, print it to screen, and wait a second

temp_val = analogRead(tempSensor);

Serial.print(”temp sensor reads “);

Serial.println( temp_val );

//delay(1000);

Serial.print(”seconds total = “);

Serial.println( seconds_elapsed_total );

//delay(1000);

Serial.print(”seconds lit = “);

Serial.println( seconds_light);

//delay(1000);

Serial.print(”proportion desired = “);

Serial.println( proportion_to_light);

//delay(1000);

Serial.print(”proportion achieved = “);

Serial.println( proportion_lit);

Serial.println();

Serial.println();

Serial.println();

Serial.println();

Serial.println();

Serial.println();

Serial.println();

Serial.println();

delay(1000);

//turn water on when soil is dry, and delay until soil is wet

//if (moisture_val < 850)

//{

//digitalWrite(waterPump, HIGH);

//}

//while (moisture_val < 850)

//{

//delay(10000);

//}

//digitalWrite(waterPump, LOW);

//update time, and increment seconds_light if the lights are on

seconds_for_this_cycle = DateTime.now() – seconds_elapsed_total;

seconds_elapsed_total = DateTime.now() – start_time;

if (light_val > 900)

{

seconds_light = seconds_light + seconds_for_this_cycle;

}

//cloudy days that get sunny again: turn lights back off if light_val exceeds 900. this works b/c the supplemental lights aren’t as bright as the sun:)

//if (light_val > 900)

//{

//digitalWrite (lightSwitch, LOW);

//}

//turn off lights if proportion_lit>proportion_to_light, and then wait 5 minutes

//if (proportion_lit > proportion_to_light)

//{

//digitalWrite (lightSwitch, LOW);

//delay (300000);

//}

//figure out what proportion of time lights have been on

//proportion_lit = seconds_light/seconds_elapsed_total;

//turn lights on if light_val is less than 900 and plants have light for less than desired proportion of time, then wait 10 seconds

//if (light_val < 900 and proportion_lit < proportion_to_light)

//{

//digitalWrite(lightSwitch, HIGH);

//delay(10000);

//}

//turn on temp alarm light if temp_val is less than 850 (approximately 50 degrees Fahrenheit)

if (temp_val < 850)

{

digitalWrite(tempLed, HIGH);

}

}