Can you post a sketch that shows how you are trying to read or write to a digital pin that doesn't work. I'm sure you are just missing some basic steps. Does the Arduino IDE example sketch 'Blink' make the on board led blink on and off continously?
Test 1 : The following script output is the LED is ON when HIGH, but dim not totoally blank when LOW.
int pin = 13;
void setup() {
// initialize the digital pin as an output.
// Pin 13 has an LED connected on most Arduino boards:
pinMode(pin, OUTPUT);
}
void loop() {
digitalWrite(pin, HIGH); // set the LED on
delay(1000); // wait for a second
digitalWrite(pin, LOW); // set the LED off
delay(1000); // wait for a second
}
TEst 2 : the following result is pin D6-D10 LED is OFF !
Yes, No LOW Command, because i want to make it all HIGH and put a LED to test is it ON or not ! So i tested result is D6-D10 is OFF when set all pins HIGH !
Very bad as that will result in damage to the output pin and/or led as there is nothing to limit the current. Search around this forum and you will see many many warnings about directly wiring leds to output pins. You need to wire a series external resistor (300-1000 ohms) to protect the output pin.
+5 to anode, cathode to Arduino?
If you wrote them low without current limit resisters, that would fry the output pins.
(arduino 'sinks' current)
If you have
arduino to Anode, cathode to ground
and you wrote them high without current limit resisters, that would fry the output pins.
(arduino 'sources' current).
Get a new chip, use 330 ohm series LEDs next time to limit current to around 10mA.
Will be plenty bright to see.
Yes - with the arduino power off, you can use a multimeter and confirm there are still connections between the header pins and the atmega pins per the UNO schematic. Would be very hard to damage the traces with the power available - but very easy to damage the transistors in the atmega.
Does the atmega chip get hot to the touch when powered on? That's usually a good indicator that it is damaged.