got issues with pin 13 at power up, blinking for a second before my codes start

Projects Programming
1

normally, if I was plugging my arduino uno into power supply, only pin 0 or 1 would turn on solid for about a second before arduino would start running the code. But after I ran the following piece of code, my arduino uno developped an issue with pin 13. pin 13 is attached to an LED and normally I was using that with only digitalWrite (k, LOW); command and all was well. the issue started when I used the following code, which seems to make them high first, then low.

But I tried uploading another sketch, with only LOW code, (without the digitalWrite (k, HIGH) section) but it still does the same thing with pin 13, as if I'm using the same code as below.

Can you please help?

void setup() {
  //set outputs
  for(int k=0;k<=13;k++) {
    pinMode(k, OUTPUT);
    digitalWrite(k, HIGH);
    
  }
  delay(400); 
  for(int k=0;k<=13;k++) {
    digitalWrite(k, LOW);
  }
  pinMode(A1, INPUT);
  pinMode(A2, INPUT);
  rtc.begin();
}

I was in the process of troubleshooting something else, and it is really frustrating to run into another issue. is there a way to hard reset or something like that?

Cheers.

2

Upload an empty (bare minimum) program to your arduino

3

J-M-L:
Upload an empty (bare minimum) program to your arduino

Already tried doing that. doesn't help.

4

(deleted)

5

spycatcher2k:
Pin 13 is used when the bootloader is started! you cant change it in code. You could customise the bootloader, and upload it to not flash the LED.

Yes, but then, why is it that until I used that piece of code, to make the outputs HIGH first and then LOW, it never happened before. even for the same sketch?

Anyway, is it easy to customize the bootloader?

Because upon power up, my pin 0 and pin 1 turn on solid for a second, and pin 13 flashes. only then my arduino starts to do what it is programmed to do. I would like none of that to happen.

Can I fix it?

6

Remove the boot loader ... (see this)

7

(deleted)

8

J-M-L:
Remove the boot loader ... (see this)

is it difficult to remove the bootloader?

I checked the link, but I'm not sure. do I need any physical tools?

will it be more complicated to upload sketches later on?

9

arduinoware:
is it difficult to remove the bootloader?

No

arduinoware:
I checked the link, but I'm not sure. do I need any physical tools?

Yes, an ISP programmer. That could either be a dedicated programmer or an extra Arduino used as "Arduino as ISP".

arduinoware:
will it be more complicated to upload sketches later on?

You will always need to use the ISP programmer to do the "Upload Using Programmer". You can always put the bootloader back by doing a Tools > Burn Bootloader.

10

Do you have something other than the onboard led connected to pin 13, and the bootloading blink is effecting that other output?

11

cattledog:
Do you have something other than the onboard led connected to pin 13, and the bootloading blink is effecting that other output?

No, on pin 13, it is just that onboard LED. it only blinks for a fraction of a second, when the system is first powered on and then it works like it is supposed to. but i don't like it. I'd rather have it removed.

Additionally, when the system is first powered on, using 9V input, also, my pins o and 1 get turned on for a fraction of second but this time it is solid, not blinking. after that, everything is back to normal and it works like a charm. so, can I remove those 3 things from the power up sequence? pins 0 and 1 solid, and pin 13 blinking shortly.?

is there an easy way?

thanks

12

We told you already - get rid of the boot loader and just use a « naked microcontroler » and then you can do what you want in the code when the processor is powered on

13

is there an easy way?

Though many different threads, you have professed and demonstrated an inability to write code.

Leaving the path which uses the bootloader and wandering into ISP territory does not seem like a wise move.

Perhaps you can put some tape over the leds if they bother you. :slight_smile:

14

J-M-L:
We told you already - get rid of the boot loader and just use a « naked microcontroler » and then you can do what you want in the code when the processor is powered on

I know that you already told me. But you did not tell me how to. Is there a link with step by step instructions?
By the way, after days of agonizing, my code is starting to finally look good. Now, I just need to sort that bootloader thing.

I found some info on how to setup another arduino as programmer but how do you actually remove the bootloader?

15

Do you have a dedicated ISP programmer?

If not, do you have an extra Arduino board?

16

What links have you looked at that were not good enough for your needs ?

Have you tried ?

17

arduinoware:
No, on pin 13, it is just that onboard LED. it only blinks for a fraction of a second, when the system is first powered on and then it works like it is supposed to. but i don't like it. I'd rather have it removed.

I'm really having a hard time seeing a problem that needs to be solved or the value added by pursuing this quest.

Also, as previously noted, given the ability level that you've demonstrated in all your previous posts, your time would probably be better spent learning some rudimentary coding skills while sticking with the standard upload / boot method.

18

cattledog:
Though many different threads, you have professed and demonstrated an inability to write code.

Leaving the path which uses the bootloader and wandering into ISP territory does not seem like a wise move.

Perhaps you can put some tape over the leds if they bother you. :slight_smile:

Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.
ALBERT EINSTEIN

I think (my opinion only), the same goes for the judger.

19

I get what you're saying but misattributing a quote to Einstein isn't a very good way to make your point.

20

Cf Quote investigator