Sniffing packets from chip CC1350

Thread Starter

Bavlos

Joined Mar 2, 2020
14
Hi guys, Im trying to write a function or interface in c++ or python that takes packet from stream of packets that CC1350 transmit and this function must return if this packet is ok or not ok related to the size of syncWordLength which it's constant for me as 20.
I can use an application that provides this which called SmartRF Packet Sniffer 2. but I need to do this as open source for connecting my code to something else .
what's confusing me that my packet is 32 bit and I configure this parametrs
RadioSetup, ID2_433_92
>,Property, protocol, VILDEHAYE
>,Property, modulation, GFSK
>,Property, msbFirst, 1
>,Property, syncWordLen, 20
>,Property, syncWord, 0x00000000
>,Property, frequency, 433920000
>,Property, deviation, 25000
>,Property, symbolRate, 100000
>,Property, rxBandwidth, 200000
>,Property, encoding, CC1310_MODE2LRM

what's confusing me that I want to sniff this packet and decide if it's ok or not, so because synWordLen is constant for all packets which it's 20 .. I want to discover from which bit till which bit does the data of syncWordLen are inserted inside my packet .. could anyone help me how could I know from which bit till which bit the data of syncWordLen found?
the packet format is found on this link http://www.ti.com/lit/ug/swcu117h/swcu117h.pdf#page=1692&zoom=100,0,456
I've read every step on that file of packet format and didn't figure out which bits from where to where does the syncWordLen data inserted inside my packet, any help please to know that ? I tried to read phy which it's related to the protocol and didn't understand very well ..

could anyone help me to understand how can I sniff my packet and to say if it's ok or not ok and where syncWordLen data is found inside my packet ?

really appreciated and Im about one week stuck on that problem
 
Last edited:

Thread Starter

Bavlos

Joined Mar 2, 2020
14
Hi guys, Im using CC1350 chip and I have two board of this, one is used as transmitted to other, I want to analyze the packets that one of CC1350 is transmitting to the other, so I downloaded https://www.sdr-radio.com/ SDR software from here for picking up the radio that the transmitter CC1350 is using to see how my packets are analyzed as 0101010101010000101010 - but modulated as RF signal .. , I succeeded to download the software SDR application but Im not succeeding to see my packets in this software although Im on the same time in parallel transmitting packets to the other CC1350 .. any help how can I analyze the packets that are transmitted from CC1350 transmitter to other CC1350 which it's receiver .. any help please? Im stuck on this about week to analyze packets that are transmitted from cc1350 to other cc1350 .. I need to see the data that this packet holds -RF signals of 1100101 - not fixed 110011 ..

thanks alot
 

Thread Starter

Bavlos

Joined Mar 2, 2020
14
Im using an SDR to see packets from CC1350 but not succeeding to see packets although Im transmitting from CC1350 .. I guess Im not using correctly the application SDR .. any help please
 

BobaMosfet

Joined Jul 1, 2009
1,059
@Bavlos
If you want to work in technical, comprehending what you're reading is *very* important. The documentation PDF you referenced was very clear:

1583266901757.png

In what section of the packet would data be stored? It's pretty self-explanatory.
 

Thread Starter

Bavlos

Joined Mar 2, 2020
14
@Bavlos
If you want to work in technical, comprehending what you're reading is *very* important. The documentation PDF you referenced was very clear:

View attachment 200547

In what section of the packet would data be stored? It's pretty self-explanatory.
In the payload, but at which bits does the suyncWorld length found .. here's my problem, Im not recognizing where in payload does the syncWorld's data found.
 

BobaMosfet

Joined Jul 1, 2009
1,059
@Bavlos-

I understand :p - I was trying to nudge you in the right direction. The syncword is not found in the payload. It's located in the packet, right after the preamble:

1583505117406.png
It exists only as a check for the receiver that is expecting a syncword in the packet to match what it's expecting. If the syncword doesn't match what it's expecting, it doesn't process the rest of the packet. Notice this really important part (I've highlighted the word 'preamble' that tells you how the length of the preamble and the syncword is defined:

1583505323642.png

That's how you know the bit sizes of both.
 

Thread Starter

Bavlos

Joined Mar 2, 2020
14
owned me :)
but I need syncWordLength and not syncWord?? I know that syncWord isn't on payload, but I was searching on syncWordLength
 
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