LED Won't Turn Off - Me TOO!

Using Arduino LEDs and Multiplexing
1

Hi folks:

I've searched this one and there are several posts, but the solutions don't speak to my issue. Ii have four LEDs on a project board with a resistor on each positive lead. I have the cathode pins on the ground strip - common ground jumper to GND on the Arduino Uno.

So, with that in mind, I fire up the following code - it starts working great, but when I turn off the LEDs, the first one (LED1) does NOT turn off. I've tried several things - different pinouts, etc., but it won't turn off. PLEASE!!! Have a look and help me if you see an issue:

//#define LED0 GND

#define LED1 A0
#define LED2 A1
#define LED3 A2
#define LED4 A3

void setup() {

pinMode(LED1,OUTPUT);
pinMode(LED2,OUTPUT);
pinMode(LED3,OUTPUT);
pinMode(LED4,OUTPUT);

}

void loop() {
// put your main code here, to run repeatedly:

digitalWrite(LED1,1);
delay(1000);
digitalWrite(LED2,1);
delay(1000);
digitalWrite(LED3,1);
delay(1000);
digitalWrite(LED4,1);
delay(1000);

digitalWrite(LED4,0);
digitalWrite(LED3,0);
digitalWrite(LED2,0);
digitalWrite(LED1,0);
}

2

Please read this:-
How to use this forum
Because your post is breaking the rules about posting code.

We also need a schematic because your description is a bit vague.

However, try putting a delay(1000 ) ; as the last instruction in the loop, because the first instruction in the loop follows the last almost immediately.

3

However, try putting a delay(1000 ) ; as the last instruction in the loop, because the first instruction in the loop follows the last almost immediately.

Might be worth a try.
If it's not helping. maybe switching leds will help?

4

Grumpy Mike have right. Add delay at the end of code at switching of led's, because instantly first Led is switch on instantly.