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Original question:

CC1200: CC1200

CC1200: cc1200

zou hang
Prodigy 40 points
Part Number: CC1200

Tool/software:


Hello,

I would like to consult a few questions regarding the CC1200:

1、The INVERT_DATA_EN configuration can invert the payload data during both transmission and reception, but the SYMBOL_MAP_CFG should have the same effect. However, it seems ineffective when configured.

2、Can the SYMBOL_MAP_CFG invert the preamble and sync word during both transmission and reception? It seems ineffective when tested.
The transmitter uses the SX1262 RF chip, and the sync word in the TX FIFO is CC CC CC CC CC CC CC CC CC CC ... CC 81, with inversion enabled. However, when the CC1200 receives with the sync word set to 33 33 33 7E, it incorrectly triggers the sync word interrupt.

3、If the CC1200 receiver is configured to not detect the preamble, will this affect its reception performance?
Could you kindly take a look at these issues when you have time? Thank you very much!

best regards!

  • 0
    TI__Guru* 85021 points

    I am not familiar with the SX1262 device so I cannot comment on how this works and how to configure the CC1200 to receive from this device, but I can comment on how the CC1200 works. 

    Assume you have a transmitter with the following 4 configurations:

    and that your receiver always use INVERT_DATA_EN = 0 and SYMBOL_MAP_CFG = 0. Sync word is 0x93 0x0B 0x51 0xDE

    Transmitting with Setting 1 and Setting 3, you will receive 0xAA 0x00 0xCC 0xFF (1) and 0x55 0xFF 0x33 0x00 (3)

    If you are transmitting with Setting 2 and Setting 4, SYMBOL_MAP_CFG is affecting the sync word, so you will need to change the sync word on your receiver to 0x6C 0xF4 0xAE 0x21.

    Keeping INVERT_DATA_EN = 0 and SYMBOL_MAP_CFG = 0 on the RX side, you will receive 0x55 0xFF 0x33 0x00 when transmitting with Setting 2, and 0xAA 0x00 0xCC 0xFF when transmitting with Setting 4

    Summarizing in a table:

    If you use CC1200 on both TX side and RX side, you will always have the same in the RX FIFO as in the TX FIFO, as long as SYMBOL_MAP_CFG, INVERT_DATA_EN, and SYNC are the same on both devices.

    As long as you have not enabled PQT gating of the sync word, it does not matter if the preamble of your transmitter does not match the preamble of the CC1200 receiver.

    Siri