hi,
have witnessed a strange behavior of my arduino uno R3.
each time i wire up a resistor into the breadboard, it simply does not work.
for instance, i wired up an LED + 1Kohm resistor to the 5V and GND, and it does not turn on.
if i wire the LED to arduino alone (without resistor, the led turns on for a split second, and then the arduino turns off , which is normal)
basically , any schematic with resistors in it fail to work.
anyone experienced this before ?
Do not use the LED without a R of about 270 ohms as you will damage the Arduino output pins.
It is possible that the LED is back to front when you connected it in the breadboard. Use 270 ohms.
Weedpharma
i know i should not connect the LED to arduino without using a resistor.
but since i couldnt figure out what wrong with this extremely basic thing, i thought the arduino was damaged already so .. i pulled off the resistor to see what was gonna happen ..
i posted picture of my set up :
btw the pins are ok. i wired a buzzer and it works ..
In that picture, you're connecting the LED incorrectly.
In a breadboard, those rows of 5 pins are connected together - so when you plug that LED in the way you did, you're connecting both sides of it to the same thing, so it can't do anything - both sides are connected to the positive supply, and nothing is in series with the resistor.
You need to rotate the diode so the pins are going into two different rows of pins, and move the power connection into that row as well.
Also, with that resistor, the diode will be dim - it's 2.2k, which is kinda high for LEDs (I hate bright LEDs, and I rarely go above 1k for the series resistor). A lot of people like 220 ohm resistors.
omg.. guys,
i'm so ashamed of myself i didnt see it . that is the newbiest thing ever .
'im sooo sorry ..
anyway, thank you very much sir !
(and to weedpharma as well)
