# light a LED

Hi, I'm new to the forum community and also Arduino. I need to solve a programming problem in Arduino and I have no idea how to start :confused: 1. In the following scenario develops a program to perform the following actions.

-As the light is in a range between 0 and 100, should completely turn on the LED. -As the light is in a range between 101 and 400, should turn the led to 50%. -In the range of 401-1023 should be off. -A second LED to 50% should ignite if it detects movement in the range of 2.1 meters to 4 meters (motion sensor). -100% if the rago of 0 meters to 2 meters :)

I have to wonder why someone who is brand new to Arduino, with no idea how to start, would arrive at such a specific description of a project. Is this an academic assignment?

Am I the only one who's missing the question mark? And code, it's the programming section after all.

And how can a light be in a range? ::)

tmd3: Is this an academic assignment?

The "1." that got copied over with it sort of gives it away doesn't it.

septillion: Am I the only one who's missing the question mark? And code, it's the programming section after all.

And how can a light be in a range? ::)

I think it means ambient light.

I think he means a variable, possibly representing the reading of an ambient light sensor :)

septillion: I think he means a variable, possibly representing the reading of an ambient light sensor :)

Considering the range (up to 1023) he's probably reading from an analog pin.

@edgar_ivan14, you need to make a start on the coding, then ask for help if you strike problems.

Use â€˜analogRead()â€™ to read the analogue output of the light sensor. Then use â€˜ifâ€™ statements to determine the light strength and light the LED appropriately, using â€˜analogWrite()â€™ on a PWM output pin to set the LED brightness.

-A second LED to 50% should ignite if it detects movement in the range of 2.1 meters to 4 meters (motion sensor).
-100% if the rago of 0 meters to 2 meters

This part is a problem - a PIR motion sensor does not measure the distance to the target. For that youâ€™ll probably need an ultrasonic â€˜pingâ€™ sensor.