### Author:  [@LauraDob](https://discourse.processing.org/u/LauraDob)
#### Post date: [March 13, 2022, 4:28pm UTC](https://discourse.processing.org/t/why-do-i-get-a-nullpointerexception/35711/1 "2022-03-13T16:28:37Z")
When I run it, I have NullPointerException [0] “COM5”… How do I fix it? This is the code
import processing.serial.\*;
Serial myPort; // Create object from Serial class
int val = 0;
int oldval = 0;
int numFrames = 2;
int frame = 0;
PImage img;
PImage[] images = new PImage[numFrames];
void setup()
{
size (1500, 1500);
images[0] = loadImage(“fase1.jpg”);
images[1] = loadImage(“fase2.jpg”);
printArray(Serial.list());
myPort = new Serial(this, “COM5”, 9600);
}
void draw()
{
if (myPort.available() \> 0) {
val = myPort.read();
}
if (val != oldval && val == 2) {
if (frame\
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [March 13, 2022, 4:36pm UTC](https://discourse.processing.org/t/why-do-i-get-a-nullpointerexception/35711/2 "2022-03-13T16:36:25Z")
Check kll’s post here: [Unable to receive serial data from Arduino - #3 by kll](https://discourse.processing.org/t/unable-to-receive-serial-data-from-arduino/14100/3)
---
### Author:  [@JSGauthier](https://discourse.processing.org/u/JSGauthier)
#### Post date: [March 13, 2022, 4:37pm UTC](https://discourse.processing.org/t/why-do-i-get-a-nullpointerexception/35711/3 "2022-03-13T16:37:41Z")
Hi there,
It is likely that you you are referencing a serial port that returns ‘null’. This means there is nothing listed as COM5.
Perhaps if you comment out //myPort = new Serial(this. “COM5”, 9600);
then read the print out in the console of the previous line -
printArray(Serial.list());
You may then
-replace Com5 with a different value from the list and see if you code runs.
or
You can check if COM5 is listed with different syntax.
Hope this helps.
Cheers,
jsg
---
### Author:  [@LauraDob](https://discourse.processing.org/u/LauraDob)
#### Post date: [March 13, 2022, 8:28pm UTC](https://discourse.processing.org/t/why-do-i-get-a-nullpointerexception/35711/4 "2022-03-13T20:28:56Z")
Hi thank you for your help but i’m 100% certain that it is COM5. So that’s not it
---
### Author:  [@glv](https://discourse.processing.org/u/glv)
#### Post date: [March 13, 2022, 8:51pm UTC](https://discourse.processing.org/t/why-do-i-get-a-nullpointerexception/35711/5 "2022-03-13T20:51:11Z")
Hello @LauraDob,
Please format your code as a courtesy to this forum:
[https://discourse.processing.org/faq#format-your-code](https://discourse.processing.org/faq#format-your-code)
You did not load an image and are trying to display it so it gives an error.
Here is an [MCVE](https://stackoverflow.com/help/minimal-reproducible-example):
Try displaying one of these images which you have loaded:
```auto
images[0] = loadImage("fase1.jpg");
images[1] = loadImage("fase2.jpg");
```
Reference:
_[Why do I get a NullPointerException? - Processing 2.x and 3.x Forum](https://forum.processing.org/two/discussion/8071/why-do-i-get-a-nullpointerexception.html)_
I do _ **not have** _ a `"COM 5"` and I get a `RuntimeException` for that:
`:)`
---
### Author:  [@JSGauthier](https://discourse.processing.org/u/JSGauthier)
#### Post date: [March 21, 2022, 2:32am UTC](https://discourse.processing.org/t/why-do-i-get-a-nullpointerexception/35711/6 "2022-03-21T02:32:52Z")
Hi @LauraDob,
I think I can see the error here. (Your insistance on COM5 being the right port was a good hint). Since you are certain that you want to reference “COM5” then you must refer to “COM5” via the address Serial.list()[index] (here the index is the value for “COM5” that is printed when you check the console following this line: printArray(Serial.list());
The console should tell you which Serial.list()[index to put].
(on my computer it prints: [0] “COM3”, it should list others like COM 5 also…)
So try changing your reference argument in Serial to something like this…
myPort = new Serial(this, Serial.list()[_place the index # here_], 9600);
Hope this helps.
Cordially,
JS
PS: Check the example files for the Serial Library for more hints on syntax for the Serial library.
---
### Author:  [@glv](https://discourse.processing.org/u/glv)
#### Post date: [March 21, 2022, 10:52am UTC](https://discourse.processing.org/t/why-do-i-get-a-nullpointerexception/35711/7 "2022-03-21T10:52:01Z")
Hello,
The error in the code from @LauraDob in this case is because _img_ is _null_.
A minimal example:
```auto
import processing.serial.*;
Serial myPort; // Create object from Serial class
PImage img;
String url = "https://media.digikey.com/Renders/Stackpole%20Renders/RC12-56Ohm-5_tmb.jpg";
void setup()
{
size (100, 100);
printArray(Serial.list());
// Either one of these will work:
myPort = new Serial(this, "COM9", 9600);
//myPort = new Serial(this, Serial.list()[0], 9600);
//img = loadImage(url); //It works with this uncommented
}
void draw()
{
image(img, 18, 18);
}
```
`"COM9"` is my Arduino COM port.
```auto
// Either one of these will work and can be interchanged:
myPort = new Serial(this, "COM9", 9600);
//myPort = new Serial(this, Serial.list()[0], 9600);
```
This is the error if you did not load an image:
It works if you load an image.
`:)`
---
### Author:  [@JSGauthier](https://discourse.processing.org/u/JSGauthier)
#### Post date: [March 21, 2022, 3:05pm UTC](https://discourse.processing.org/t/why-do-i-get-a-nullpointerexception/35711/8 "2022-03-21T15:05:10Z")
Thanks @glv,
Your care and attention to detail is appreciated. I’ll task myself to apply that same care in my responses moving forward. Keep up the kind work!
✌