Hi All!
I have a beginner's question, I cannot find an answer on the Internet. So I've just started with Arduino and I'm connecting leds to digital pins. The strange thing is that if I connect LED (through resistor) to pins 12 and 11, LED is bright, but on other digital pins I could hardly notice its light. Seems that the voltage on different pins is different. What could be the problem?
Have you declared the pin as an output?
Weedpharma
No. It helped, thanks!
In the manual I've read it was written that pins are initialized for output by default. But seems like it is better to do everything explicitly.
That manual is wrong. On reset all the pins go to INPUT. Pin 13 is set to OUTPUT by the bootloader so that may still be an OUTPUT when your sketch starts. Best to initialize everything you use in your sketch.