Make S2-LP talk to nRF905

[Witek]

Hello,

I have a need to make the S2-LP communicate to an existing RF system which is based on the nRF905. From the reading I have done it looks like it should be possible. 

Does anyone have any suggestions on how to configure the S2-LP to do the job?

Thanks

Witek

[TIomm.1]

Hello,

I am struggling with the same problem. Have you by any chance figured it out?

I am trying to get S2-LP to receive nRF905 messages. I managed to achieve transmission in the reverse direction (nRF905 receiving S2-LP messages), but am struggling with this one. I have configured the nRF905 to work at the frequency of 868.2 MHz (CH_NO = 0b001110101) and set the S2-LP to work at 867.995564 MHz.

  

I have read here: https://devzone.nordicsemi.com/f/nordic-q-a/47122/nrf905-preamble (was it also your thread by any chance? :D) that the preamble transmitted by nRF905 is 0x055599 (already Manchester encoded), and so this is what I set my S2-LP's SYNC value to, hoping that it would pick up on the transmission. I also use the same parameters as mentioned in the forum thread I linked. When using the S2-LP DK GUI I can see that I am receiving transmissions from the nRF905 but the payloads are all wrong/mangled. That is if I set the sync word length to 0 (ignore it), if I set the sync word to 0x55599, I get nothing.

 

Do you have any tips on what I may have missed? Modulation method maybe?

Any help would be tremendously appreciated.

Thanks in advance,

Tony

[Winfred LU]

> When using the S2-LP DK GUI I can see that I am receiving transmissions from the nRF905 but the payloads are all wrong/mangled.

Maybe it is because the data is Manchester encoded?

Try to enable Manchester coding for data by: setting '1' to the MANCHESTER_EN bit in PCKTTRL2 register.

Note that for S2-LP, Manchester encoding is only applied to bits following SYNC word.

[RWate.1]

Hello,

I am struggling with the same problem. nRF905's documentation doesn't explicitly say which type of modulation to choose (it only says it's GFSK). Manchester modulation is enabled (although I also tried receiving nRF messages without manchester encoding enabled on S2-LP and with no sync word in order to perhaps see in the message payload the nRF905 preamble pattern). And when I set the sync word to 0x00055599, I get nothing :(

From what I read, the nRF905 transmits the following pattern as a preamble/sync word: 01010101010110011001, am I right that for S2-LP to match against this, I should set the sync word in GUI to 0x00055599 (SYNC0=0x00, SYNC1=0x05, SYNC2=0x55, SYNC3=0x99)?

[Winfred LU]

>From what I read, the nRF905 transmits the following pattern as a preamble/sync word: 01010101010110011001, am I right that for S2-LP to match against this, I should set the sync word in GUI to 0x00055599 (SYNC0=0x00, SYNC1=0x05, SYNC2=0x55, SYNC3=0x99)?

That looks right. And the SYNC_LEN (in PCKTCTRL6) shall be 0x14.

[Witek]

Hi Tony,

Apologies for the late replay. I have not been on this project for a while. And unfortunately I have not been able to figure it out. I set up the S2-LP GUI the same as you (except for the frequency as I work on 433MHz). When transmittin from S2-LP i am albe to receive messages on nRF905. But, somehow how well I receive depends on the content of the message. For example, when I set the payload to all 0xE7 then the nRF905 receives some 40% of the messages. When I set to payload to all 0xAA, then the number is around 90%. Also, when I change a few bytes from 0xE7 to something else then all the following byes are mangled up.

When sending messages from nRF905 to S2-LP, then then messages are received (at some 50% loss) but the data is all wrong.

Have you had any success since your post?

Thanks

Witek

[Witek]

Hi Winfred,

I am unable to make the 2 chips communicate reliably. Can you please share information on how to configure the S2-LP? The nRF905 is very inflexible as far as configuration goes.

Thanks

Witek