Problem with setting the maximum preamble length

End Devices (Nodes) LMIC
1

Hi,

Can any one tell me that how to set the preamble symbol in LMiC library?
I changed in lorabase.h as
enum { STD_PREAMBLE_LEN = 65500 };

I also tried in lmic.c in the following portion
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But I didn’t get any change in the air time. Can anyone help me in this matter?

Asif

2

No idea, but what do you mean by change the preamble symbol ?

I thought the preamble bit pattern was fixed, although you can alter the length of the preamble, but why would you want to do that ?

3

Hi,
Thanks for your reply. If I want to alter the length of preamble symbol, how can I do that?
I want to detect the presence of preamble symbol by another device using CAD.

Asif

4

I dont know how to do it in LMIC, but its a register on the LoRa device that sets the length, so you would be able to check the LMIC code to see if it writes to that register.

But why, you would be able to do CAD on the standard pre-amble in any case …