# Arduino LED strobe light with a MOSFET

I have 6 IR LEDs that I want to run off a cigarette lighter outlet in a car. (High output infrared LED 5mm 1.2VDC 100mA 940nm)

Currently I have all six in series with a 100ohm 1w 5% resistor.

I am going to use the Arduino Uno as a timer. Output on Pin 2.

int led = 2;

void setup() {
pinMode(led, OUTPUT);
}
void loop() {
digitalWrite(led, HIGH);
delay(35);
delayMicroseconds(544);
digitalWrite(led, LOW);
delay(35);
delayMicroseconds(552);
}


My 6 leds are in the place of "M". But for some reason this is not working for me.

The leds are sometimes off, blink at the inncorrect freq, or just stay lit.

• Is there any particular reason why you're using a circuit for a motor with a kickback diode? I would just pull the 1N4001 and try again. – Dave May 20 '11 at 5:19
• @Dave Maybe it is used to denote a large load. – 0xakhil May 21 '11 at 18:02
• @0xakhil - In any case, it isn't the proper schematic! Dave's point was valid. – Kevin Vermeer May 23 '11 at 3:28
• Can you revise your schematic? The current image isn't correct. For one thing, you'll want current limiting somewhere. – Kevin Vermeer May 23 '11 at 3:29