Hydro 9000

ABOUT

In this project, I create a device to water five indoor potted plants by measuring the moisture level in the soil and automatically pumping water when it becomes too dry. The device is powered by a standard 5 volt USB cable and pumps water from a reservoir (I reuse an empty tub of peanut-butter pretzels).

This was the first time I’ve used a 3D printer and it was incredibly fun! I learned how to use an XYZ Da Vinci Mini printer, how not to model parts in CAD, and just how small 8Kb of RAM is. Below is a step by step overview on how I created the Hydro9000.

THE PROBLEM

So…let me start by saying I love having plants indoors. However, my plants don’t seem to last as long as they should…due to a lack of water. SO! The problem is: plants need water and I’m terrible at giving them water.

THE SOLUTION

Water the plants. NO. That’s boring and as stated previously, I kill plants.

THEBETTER SOLUTION

I need to create a machine to water the plants for me! Obviously, I’ll need a control panel, a soil moisture sensor for each plant, a big red emergency stop button, a color display, a key to lock out my roommate, colorful 3D printed housing for the pumps,…okay, okay, let’s get started!

RESOURCES

Github

COMPONENTS

SOFTWARE TOOLS

DIAGRAM

CODING SAMPLE

main.cpp
void setup() {
  Serial.begin(115200);
  Serial.println("Starting...");
            
  Hydro9000::setCurrentMillis(0);
  unsigned char sensorPins[PLANT_COUNT] = {54, 55, 56, 57, 58};
  unsigned char pumpPins[PLANT_COUNT] = {30, 34, 38, 42, 46};
  String plantNames[PLANT_COUNT] = {"Basil", "Cilantro", "Oregano", "Thyme", "Rosemary"};
  for (unsigned int i = 0; i < PLANT_COUNT; i++) {
    MoistureSensor sensor(sensorPins[i]);
    WaterPump pump(pumpPins[i]);

    PlantController plant(sensor, pump);
    plant.name = "plant_"+String(i);
    plant.displayName = plantNames[i];

    hydro.addPlantController(plant);
  }
  
  ControlPanel controlPanel;

  attachInterrupt(digitalPinToInterrupt(SELECT_WHEEL_ENCODER_PIN_A), doEncoderPinARising, RISING);
  attachInterrupt(digitalPinToInterrupt(SELECT_WHEEL_ENCODER_PIN_B), doEncoderPinBFalling, FALLING);
  selectWheel = SelectWheel(SELECT_WHEEL_ENCODER_PIN_A, SELECT_WHEEL_ENCODER_PIN_B);
  selectWheel.readPinA();
  selectWheel.readPinB();
  controlPanel.addSelectWheel(selectWheel);

  /* Add buttons to control panel */
  Button blueButton(BLUE_BUTTON_PIN, BLUE_BUTTON_LED_PIN);
  Button redButton(RED_BUTTON_PIN, RED_BUTTON_LED_PIN);
  Button selectWheelButton(SELECT_WHEEL_BUTTON_PIN);
  Button emergencyStopButton(EMERGENCY_STOP_BUTTON_PIN);
  Button keySwitch(KEY_SWITCH_PIN);
  blueButton.stateWhenButtonPressed = LOW;
  redButton.stateWhenButtonPressed = LOW;
  selectWheelButton.stateWhenButtonPressed = LOW;
  controlPanel.addButton(ControlPanel::ButtonName::BLUE, blueButton);
  controlPanel.addButton(ControlPanel::ButtonName::RED, redButton);
  controlPanel.addButton(ControlPanel::ButtonName::SELECT_WHEEL, selectWheelButton);
  controlPanel.addButton(ControlPanel::ButtonName::EMERGENCY_STOP, emergencyStopButton);
  controlPanel.addButton(ControlPanel::ButtonName::KEY_SWITCH, keySwitch);
  
  hydro.addControlPanel(controlPanel);
  hydro.setup();

  Serial.println("Hydro900 setup complete");
}

void loop() {
  hydro.update();
}