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Posts: 9
Registered: ‎07-13-2017

receive start time after RAIL_RxStart

I do not have a preamble on my system, and I can not use Sync Word, because the reception is not perfect, and exact sync words do not work in every packet, because of this some of the packages are lost. because of this I'm trying to somehow get a continuous regime. The use of this chip (efr32fig1v) is very attractive to me, as it supports the reception frequency from 118 MHz.

 

to get an infinite mode of receiving 4fsk-data in efr32fg1v131, I plan to use these two chips. connect the end of the received packet of the first chip with the beginning of the packet of the received second chip. I understand that the reception does not begin immediately after the command RAIL_RxStart. I want to put the first package in the second package and define the boundary and match the packages with the maximum match.

 

How long does the reception start after the RAIL_RSStart command (how many characters is skipped)?

 

total preamble length = 0
The synchronization word 0 = 0xff
Synchronizing word 1 = 0x00
sync word length = 1

 

can you advise something for implementation?

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Posts: 254
Registered: ‎12-10-2013

Re: receive start time after RAIL_RxStart

The chip can't work without preamble and sync word since the chip can't lock its timing and frequency through preamble and can't decide where the packet payload starts. Thanks, Juanbyong
Posts: 9
Registered: ‎07-13-2017

Re: receive start time after RAIL_RxStart

At me with a chip efr32fg1v131, length of a preamble = 0, length of a sync word = 1 bit, modulation 4fsk, it is normally synchronized and the packet is accepted. The length of the packet is 230 bytes. The only thing I do not understand is that the internal symbols -1dev and + 1dev are inverted, do not match the chosen map. But I really do not have enough of an infinite regime. Because of the need to constantly re-start the RAIL_RSStart, 4 to 5 characters are lost (9600kb).

 I customize the tuning frequency by "manual" function RAIL_SetFreqOffset. after turning I ask configuration AFC_FREE_RUNNING, with a short length of the package, I interrogate RAIL_GetRxFreqOffset several times, averages the values, and then expose the maximum length of the packet with INTERNAL_ALWAYS_ON, and is fixed at the resulting offset frequency, and if the correct data is not some piece time, I again repeat batt frequency auto-tuning