I`m new to electrical engineering, so it's probably a newbie problem.

I'm using a wall power supply(5V-2A) to power the [DC Motor][1] and the Attiny85.

A C1 470uF to make the power more stable. I don't know if it is necessary, but it helped.

A D1 green led to show if it's on.

A reset button connected to ground to reset(Duh).

One relay(833H-1C-C) connected to the digital pin 0 of the attiny to turn the motor on and off.

Two rotational potentiometer connected to two analog pins(2,3) to decide how much time the mini water pump will be on(0-1023 to 1s-30s) and the other to compare to the humidity sensor to decide how dry the soil will need to be to turn on the motor.

And one [humidity sensor][2].

    #include "kPot.h" // my library, just analogReads
    
    #define HUMIDITY_PIN 1 //humidity sensor
    #define LEVEL_PIN 3 //rotational potentiometer
    #define TIMER_PIN 2 //rotational potentiometer
    #define MOTOR_PIN 0 //connected to the relay switch
    
    kPot humiditySensor = kPot(HUMIDITY_PIN, 10); //(pin, average of 10 reads)
    kPot levelPot = kPot(LEVEL_PIN, 10);
    kPot timerPot = kPot(TIMER_PIN, 10);
    
    int humidity = 0;
    int level = 0;
    int timer = 0;
    
    void setup() {
      pinMode(MOTOR_PIN, HIGH);  

      humidity = humiditySensor.Read();
      level = levelPot.Read();
      timer = timerPot.Read();
    }
    
    void loop() {
      humidity = humiditySensor.Read();
      level = levelPot.Read();
      
      timer = timerPot.Read();
      timer = map(timer, 0, 1023, 1000, 30000); //1s to 30s
      
    
      if(humidity < level){
        digitalWrite(MOTOR_PIN, HIGH);
        delay(timer);
        digitalWrite(MOTOR_PIN, LOW);
      }
    
      delay(300000); // 5min Update
    }

[![enter image description here][3]][3]


The problem: The mini water pump turns on and won't stop.<br>
I removed the reset button to make sure that wasn't resetting, didn't help.<br>
Maybe the motor is taking too much current and reseting the attiny?<br>
I probably have to put a diode somewhere, but as I said, I'm a newbie, so...

thanks.


  [1]: http://www.dx.com/p/hsyy01-water-pump-motor-w-hose-white-silver-236808#.VqvzTfkrKHs
  [2]: http://www.dx.com/p/soil-humidity-moisture-detection-sensor-module-blue-black-white-200142#.VqwBW_krKHs
  [3]: https://i.sstatic.net/4554d.jpg