How to extract a string value

General
1

Hello Everybody,

I am working on a RS485 serial to ifttt project.

I receive the string "INPUTSTATUS 0924400005454010004411444100444111447855" and I would like to extract only the second number, in this example "9".

I am using the palette "string" but I don't know how to setup it to extract the value.

Can you please help me?

2

I'd use a function node. Assuming the data is in msg.payload:

let number = msg.payload.split(' ')[1].substr(1,1)
3

you probably mean (to be complete for mike829)

msg.payload = msg.payload.split(' ')[1].substr(1,1);
return msg;
2 Likes
4

Yes, should have documented better. :slight_smile: Thanks @dceejay.

5

Thank you so much, so if i put substr(0,1); I read the first value, if i put substr(1,1); I read the second value, if I put substr(2,1); I will read the third value. Is it correct?

6

Correct..

7

Thank you so much for your help. It works fine...

8

Sorry again...Is it also possible to convert the hex I've extract to binary? If it is 9 I would like to obtain 1001.
So I will have

1 > state input 1 on
0 > state input 2 off
0 > state input 3 off
1 > state input 4 on

Now I am using the code in hex: If it is 9> 4 and 1 are on. If it is 1 > 1 is on. If it is 8 > 4 is on. If it is 3 > 1 and 2 are on.

9

Maybe this would help?

10

Thanks for the link. I will check into it

11

now I am trying to extract the string: { var: "5555 INFO 1" } to obtain only 5555 INFO 1.

I edit the function '' msg.payload = msg.payload.split(" ")[1].substr(5,10);
return msg;'''

but doesn't work...

12

That’s not a string. msg.payload in that example is an object.
Have you read the page “ working with messages” in the docs? Which would help you to differentiate them.
the bit you want is msg.payload.var

13

I will look into “ working with messages”, thank you. I think that I can use string palette and chomp. Thank you so much.

14

or as i said before just use msg.payload.var

15

It works using mg.payload.var and it is perfect to use chomp function to cut var: " and the final". I obtained the perfect string at the output. So thank you so much for the help.

1 Like