DC Motor trigger

Using Arduino Project Guidance
1

i am brand new with Arduino....as in i got a kit a few days ago. so any guidance is helpful.

I am looking to trigger a dc motor with a cell phone flash. i am thinking of using a phototransistor. will this be possible?

2

I am looking to trigger a dc motor with a cell phone flash. i am thinking of using a phototransistor. will this be possible?

Yes perfectly possible.

Get your photo transistor, wire it up to a digital input, collector to the input emitter to ground and enable the pull up resistors.

Then have another pin set to be an output, connect it to the base of a transistor through a 1K resistor. Emitter of this transistor to ground. Collector to the motor, other end of the motor to the + of the motor power supply. Connect the - of the motor power supply to the Arduino ground. Connect a 1N4001 diode anode to the collector cathode to the + of the motor supply.

Software.
When you see a LOW on the digital input pin, put a HIGH on the output pin.

3

I am trying to trigger a dc motor to rotate 360 degrees when a flash from a cell phone hits a phototransistor but i am having some issues figuring out how to do this. any help would be amazing.

I have attached a photo of my setup. not sure if going in the right direction.

4

I have attached a photo of my setup. not sure if going in the right direction.

No you haven't.

5

I am trying to trigger a dc motor to rotate 360 degrees

Just 3600? That is impossible without some feedback mechanism and some gearing.

6

I guess what I am looking to do is for the flash to turn the motor on for one second and then turn off.

7

Simplest possible version

// you can use any digital pins here...
int flash_in = 3;  // flash sensor connected to digital input 3
int motor_out=5; // motor connected to pin 5


void setup() {
  // initialize the digital pins.
  Serial.begin(9600);
  pinMode(flash_in, INPUT);
  pinMode(motor_out, OUTPUT);  
}

// the loop routine runs over and over again forever:
void loop() {
  if (digitalRead(flash_in)) {
     digitalWrite(motor_out,1); // turn on the motor
     delay(1000);               // wait for a second
     digitalWrite(motor_out,0);  // turn off
  };
}

Better version (avoids using delay() so other things can happen in between)

// you can use any digital pins here...
int flash_in = 3;  // flash sensor connected to digital input 3
int motor_out=5; // motor connected to pin 5


void setup() {
  // initialize the digital pins.
  Serial.begin(9600);
  pinMode(flash_in, INPUT);
  pinMode(motor_out, OUTPUT);  
}

// the loop routine runs over and over again forever:
void loop() {
  unsigned long int motor_off_time=0;

  if (digitalRead(flash_in)) {
     digitalWrite(motor_out,1); // turn on the motor
     motor_off_time=millis()+1000; 
  }     
  if (millis()>=motor_off_time) { 
    digitalWrite(motor_out,0);  // turn off
  };
}
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