user51378: Hi I am learning Arduino. Pin 13 lights the LED's very brightly. With subsequent LED's on other ports the LED's are much less bright than the one on 13.
Anyone know what is going on?
regards

user47766: You probably have cheap crappy inefficient leds on the other pins. Or you have the wrong value resistor in series with them. If they are not from the same batch, with the same resistor, you can't really complain. Maybe they are for a higher voltage. (because of the resistor value)
Are you sure you set the port pins for output?
pinMode(Output_PIN, OUTPUT);


51378: <p>Hi I am learning Arduino. Pin 13 lights the LED's very brightly. With subsequent LED's on other ports the LED's are much less bright than the one on 13.</p>

<p>Anyone know what is going on?</p>

<p>regards</p>
 47766: <p>You probably have cheap crappy inefficient leds on the other pins. Or you have the wrong value resistor in series with them. If they are not from the same batch, with the same resistor, you can't really complain. Maybe they are for a higher voltage. (because of the resistor value)</p>

<p>Are you sure you set the port pins for output?</p>

<pre><code>pinMode(Output_PIN, OUTPUT);
</code></pre>
