Dark Sensitive Interactive Light Using 20 Segment Bar-Graph and Arduino
The Project is based on 20 Segment Bar Graph (2X10 LED PCB), Arduino Mega and LDR, The project converts darkness into a number of LEDs, number of LEDs will glow proportional to darkness falls on LDR. The circuit works with 12V DC and draws 4 Amps while all LEDs are ON. Digital pin D22 to D41 of Arduino used to drive LEDs.
Arduino Code
/*
* Dark Sensitive interactive LED Light , The project consist 20 segment Bar-graph white LEDs ,
* Driver transistors for LEDs, LDR, Pull Resistor for LDR and arduino mega
* Code writen for arduino mega, Arduino code, schematic, PCB layout
available at our website www.twovolt.com, This also can be used as dark senst
*/
// these constants won’t change:
const int analogPin = A0; // the pin that the potentiometer is attached to
const int ledCount = 20; // the number of LEDs in the bar graph
int ledPins[] = {
22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41
}; // an array of pin numbers to which LEDs are attached
void setup() {
// loop over the pin array and set them all to output:
for (int thisLed = 0; thisLed < ledCount; thisLed++) {
pinMode(ledPins[thisLed], OUTPUT);
}
}
void loop() {
// read the potentiometer:
int sensorReading = analogRead(analogPin);
// map the result to a range from 0 to the number of LEDs:
int ledLevel = map(sensorReading, 350, 950, 0, ledCount);
// loop over the LED array:
for (int thisLed = 0; thisLed < ledCount; thisLed++) {
// if the array element’s index is less than ledLevel,
// turn the pin for this element on:
if (thisLed < ledLevel) {
digitalWrite(ledPins[thisLed], HIGH);
}
// turn off all pins higher than the ledLevel:
else {
digitalWrite(ledPins[thisLed], LOW);
}
}
}
