# Loop For for Arduino used as meter light

## Continuing the loop FOR on Arduino

In the previous post we saw an example with the FOR loop of Arduino. It termed as a loop default, that always know few turns will give, this is true but not entirely, in the example above use constant at the time of define the loop knew the number of turns that would give not only before run the FOR but during all the program.

In this example we are going to get a measurement of a light sensor and the digital outputs from the 2 to the 13 to create a light meter.

## Explaining the program of the FOR loop for Arduino

1. Configure all the pins as output and so equal to that in the previous example we will use a FOR loop, easier than writing it 12 times.
2. Get the value of the sensor (is connects to an input analog) the value is understood between 0 to 1024, we have twelve lights that is Iran turning as more luminosity reaches.
3. We divide the value of the sensor between 85.34 and save it in an int variable, being the maximum value 11, then we add 2 (thus the Rx and Tx pins left free).
4. We do a FOR loop from 2 to 13 to pay all pins.
5. We do a FOR loop from 2 to the value from step 3, so that only those pins, turn on us as we see we don’t know a priori the number of turns of the loop, but if we know exactly how many laps you will give when it starts.

## Program

```int i;
void setup() {}

for(i=2; i< 14; i++)
{
pinMode(i, OUTPUT);
}
}

void loop() {}
int valor_luz;
valor_luz = valor_luz/85.34;
valor_luz = valor_luz + 2;

for(i=2; i< 14; i++)
{
digitalWrite(i, HIGH);
}
for(i=2; i< valor_luz; i++)
{
digitalWrite(i, LOW);
}
}

```