How to Extracting a binary integer data from a msg.payload?

[Fef_38]

Hi,
I’m a beginner and I don’t understand what happene with “binary” node
I receive from MQTT node a msg.payload in binary format: the fields are 12 32bit integers in little endian, like bellow:
F0CC0100581B0000D02F0000DE670000525300003A570000225B00000A5F0000F2620000DA660000C26A0000AA6E000041
I have not separator between each integer.
To read my data I use the binary node and I extract the data like it:
l32 => d0, l32 => d1, l32 => d2, …. l32 => d11
And I read that :
d0 :0x1fdfd (d130557)
d1: 0x1b58
Etc…
d0 (0x1fdfd ) is wrong, the data is F0CC0100 in little endian and 0x0001CCF0 = 118000

I saw when a byte has bit 8 = 1 the conversion is false…
I try with -l31 but the result is bad too!
Do you know why? Any suggestion?

[Steve-Mcl]

If you dont mind installing a contrib node, then node-red-contrib-buffer-parser can do all the heavy lifting for you.

Here I demonstrate 3 ways you can convert your numbers (1 object, multiple payloads or single items (fan out) ...

Flow

Results

Single object

individual items

fan out

Demo Flow (to import)

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[Fef_38]

Hi,
Thank you very much for your reply
From your demo flow I found my mistake!
In the begging I used the payload with raw values
Now I transform the payload into a Hex buffer:
mvk=msg.payload.data;
msg.payload = Buffer.from(mvk, "hex")
return msg;
after I use the binary node without problem...
And now All work well!
Thank again.