Auto Water UNO

AutoWater

Automatic watering control algorithm for Arduino-based systems.

This repository contains C++ code implementing an automatic watering controller intended to run on Arduino-compatible boards. The controller reads soil moisture sensors and controls pumps/valves via MOSFETs or relays. It includes configurable thresholds, scheduling, and safety checks to avoid over-watering and to recover from sensor noise.

Features

• Read soil moisture sensors (analog or digital)
• Control up to 4 pumps/valves via MOSFETs (low-side switching)
• Hysteresis and moving-average filtering to reduce sensor noise
• Minimum-on and minimum-off timing to protect pumps
• Optional scheduling support (time-based watering windows)
• Serial logging for debugging

Hardware (Arduino UNO + 4 pumps)

This project was developed for an Arduino UNO controlling four pump motor switches (MOSFETs) from digital pins.

Typical hardware components:

• Arduino Uno
• Soil moisture sensor(s) (capacitive recommended)
• 4 x logic‑level N-channel MOSFETs or a 4‑channel MOSFET driver to switch pump power (low-side switching)
• 12V (or appropriate) DC pumps — powered from a separate supply sized for pump current
• Common ground between Arduino and pump power supply
• Optional flyback suppression (diode/RC/T VS) or snubber network across pumps
• Optional float sensor for tank low-level detection

IMPORTANT safety notes

• Do NOT drive pumps directly from Arduino pins. Use MOSFETs or relays and a separate power supply for pumps.
• Ensure the MOSFETs are logic-level (fully enhanced at 5V gate drive) and rated for the pump current and voltage.
• Provide flyback/EMI suppression for the pumps (RC snubber or TVS). Many DC motor pumps produce voltage spikes; add protection to avoid damaging the MOSFET or Arduino.
• Use fuses and proper wiring practices for mains-powered or high-current systems.

Example wiring (4 pumps):

• Soil moisture sensors: analog input pins (A0, A1, ...)
• Pump control (low-side MOSFET gate): digital pins D4, D5, D6, D7
• MOSFET source -> ground (common ground with Arduino)
• MOSFET drain -> negative pump terminal; pump positive terminal -> external power supply positive
• Optional float/level sensor: digital input (with pull-up/pull-down as required)
• Serial: USB to host for logs and configuration

Example pin mapping

• pumpPins[0] = 4
• pumpPins[1] = 5
• pumpPins[2] = 6
• pumpPins[3] = 7
• moistureSensor = A0

Building and Uploading

You can build and upload the code using the Arduino IDE or PlatformIO.

Arduino IDE:

1. Open the .ino or main .cpp file in the Arduino IDE.
2. Select Arduino/Genuino Uno as the board and the correct serial port.
3. Click Upload.

PlatformIO (VSCode):

1. Open the project in VSCode with PlatformIO installed.
2. Configure platformio.ini for board = uno.
3. PlatformIO: Upload to compile and flash.

Configuration

Configure pins and algorithm parameters in the config.h or top of the main sketch:

• Sensor pins (e.g., A0)
• Pump control pins (e.g., D4..D7)
• Moisture thresholds (dry/wet)
• Hysteresis and smoothing window size
• Minimum pump on/off durations
• Optional schedule windows

Example parameter names and sample values you may find in the code:

• MOISTURE_DRY_THRESHOLD = 600
• MOISTURE_WET_THRESHOLD = 400
• MIN_PUMP_ON_MS = 30000 // 30 seconds
• MIN_PUMP_OFF_MS = 300000 // 5 minutes

Adjust these values for your sensors and soil type.

Minimal example sketch

// Example: minimal sketch showing pin defs and a simple control loop
const int moisturePin = A0;
const int pumpPins[4] = {4, 5, 6, 7};
const int MOISTURE_DRY = 600;
const int MOISTURE_WET = 400;
const unsigned long MIN_ON_MS = 30000UL;
const unsigned long MIN_OFF_MS = 300000UL;

unsigned long pumpOnTime[4] = {0,0,0,0};
unsigned long pumpOffTime[4] = {0,0,0,0};
bool pumpState[4] = {false,false,false,false};

void setup() {
  Serial.begin(9600);
  for (int i = 0; i < 4; ++i) pinMode(pumpPins[i], OUTPUT), digitalWrite(pumpPins[i], LOW);
}

void loop() {
  int reading = analogRead(moisturePin);
  Serial.print("Moisture: "); Serial.println(reading);

  unsigned long now = millis();
  bool needsWater = (reading >= MOISTURE_DRY);

This is a very small example to demonstrate pin mapping and timing constraints; adapt it to your full algorithm (filtering, hysteresis, averaging, scheduling).

Algorithm Overview

Each cycle, the controller:

1. Reads the soil moisture sensor (optionally averaging several samples).
2. Applies hysteresis to decide whether the soil is dry or wet.
3. Enforces minimum on/off times before switching pump state to protect hardware.
4. Optionally respects a schedule (only water during configured windows).
5. Logs events over Serial for debugging and telemetry.

Safety & Limitations

• Test with a dry run (disable pump driver) before connecting pumps to verify sensor behavior.
• Ensure pump wiring and MOSFET selection follow safety guidelines and the pump manufacturer's recommendations.
• Add fuses and current protection as appropriate for your pump.
• The code assumes reliable sensor readings; adding redundancy or float switch protection is recommended for production systems.

Contributing

Contributions and improvements are welcome. Please open issues or PRs with:

• Hardware compatibility notes
• Improvements to the control algorithm
• Additional safety checks or telemetry

License

This project is provided under the MIT License. See LICENSE (or add one) for details.

Contact

Repository owner: prkerrigan