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CC1200: RX bit rate and other settings?

Prodigy 195 points

Replies: 31

Views: 266

Part Number: CC1200

Hello

I am trying to get the CC1200 to work with an established RF network. I have matched the basic things, like sync byte, bitrate, modulation (2GFSK), frequency etc (an I also have a spectrum analyser). I more or less see packets come through. However they seem to be exhibiting a very high bit-rate error. It almost looks like the bitrate is not perfectly matched. I've had a look through the registers, but one setting I would very much like to adjust the bitrate tolerance on the CC1200. As well as anything else you think would help. 

How do I do this?

Thank you

31 Replies

  • Prodigy 287125 points

    If the established network is of newer data (last 15 years or so) the datarate is most likely set by a crystal and therefore the tolerance should be tight. I would suspect other settings. 

    Would you be able to post how you have set up the radio now? 

    If you have used SmartRF Studio to try to receive the packets on the network, please post a screendump of the SmartRF Studio window so I can see how the bi errors look like. 

     

  • In reply to TER:

    Hi Ter

    Thank you very much for your reply. Truthfully right now its a little bit of a mess as I have been trying to (unsuccessfully) tweak settings. I will have this ready with (hopefully) your next reply. Both sides are crystal controlled. One is based on a 25MHz crystal while the TI solution is 40MHz. While the absolute values will be tight I wondered if they are unable to reach the same values, perhaps the steps are too large, This could go for the actual RF frequency as well. 

    Many others have the ability to change this setting(at least in OOK mode, not sure if this setting is for the 2GFSK). Are there any settings like this? I go have a good go at it then post my best attempt. Please note the data is whitened with a different algorithm that TI use. I can't see anyway to change that either. 

    Kind regards

  • Prodigy 287125 points

    In reply to Bryce Smith1:

    "unable to reach the same values": Not sure what exactly you are referring to here. 

    To be able to help you I would need more data since at this point I have no knowledge of how you are trying to set up the radio. 

     

  • In reply to TER:

    Hello Ter

    Thank you again for your reply and I understand. I will try and provide you with everything. I don't appear to be able to paste in screen grabs, but will paste in what I can.

    My settings

    Frequency = 433.42Mhz

    Symbol rate = 25 kbps

    Bit Rate = 25 kbps

    Deviation = 15 kHz

    Preamable 0xAA.....

    Sync Word AAAAAAAB

    Preamble count = 3 bytes

    What I receive

    I only get a message when I should. However it of course looks wrong. I know the other end is data whitened, however I would expect the first nibble of the data to be consistent at least - I could be wrong on that point, but from my understanding that should be the case. 

    07:45:10.065 | aa aa aa aa aa aa aa aa aa aa aa aa aa a9 99 99 99 95 56 aa a6 aa 56 aa aa aa aa aa aa aa aa a9 6a aa 69 6a aa aa a5 9a a9 95 65 66 96 55 aa 65 5a 6a 66 69 a9 96 66 5a 5a 9a 96 5a aa aa aa a9 69 9a 5a 54 b6 bf b9 eb 51 bb c3 56 e4 a2 56 b2 8e 68 eb ff f5 f6 a5 f1 d8 8a 56 db 52 b5 5b 6d 2d 72 8d 5a | -36 CRC error

    07:45:10.990 | aa aa aa aa aa aa aa aa aa aa aa aa a9 99 99 99 95 56 aa a6 aa 56 aa aa aa aa aa aa aa aa a9 6a aa 69 6a aa aa a5 9a a9 95 65 66 96 55 aa 65 5a 6a 66 69 a9 96 66 5a 5a 9a 96 5a aa aa aa a9 69 9a 5a 54 cd ff 7e 56 d7 5f eb ed 55 92 3b 0e c6 1a 35 5f 88 e9 1a aa 6a 51 58 aa 83 d4 77 4a a1 62 d4 f6 a5 | -37 CRC error

    07:45:12.268 | aa aa aa aa aa aa aa aa aa aa aa aa a9 99 99 99 95 56 aa a6 aa 56 aa aa aa aa aa aa aa aa a9 6a aa 69 6a aa aa a5 9a a9 95 65 66 96 55 aa 65 5a 6a 66 69 a9 96 66 5a 5a 9a 96 5a aa aa aa a9 69 9a 5a 54 bf 1f d2 aa bb 65 75 ac ed a9 21 b5 0e ea e2 eb d3 a6 5b b9 f5 92 94 95 ac a8 c8 29 ad 05 52 cd 94 | -30 CRC error

    07:45:13.435 | aa aa aa aa aa aa aa aa aa aa aa aa aa 66 66 66 65 55 aa a9 aa 95 aa aa aa aa aa aa aa aa aa 5a aa 9a 5a aa aa a9 66 aa 65 59 59 a5 95 6a 99 56 9a 99 9a 6a 65 99 96 96 a6 a5 96 aa aa aa aa 5a 66 96 95 26 37 ee 37 a6 d2 be 5b 68 53 55 4a d5 34 5a 4b 55 45 48 cd 69 66 ad ab 6a af 68 ab ad 4a a9 4c 66 | -30 CRC error

    07:45:14.557 | aa aa aa aa aa aa aa aa aa aa aa aa aa 66 66 66 65 55 aa a9 aa 95 aa aa aa aa aa aa aa aa aa 5a aa 9a 5a aa aa a9 66 aa 65 59 59 a5 95 6a 99 56 9a 99 9a 6a 65 99 96 96 a6 a5 96 aa aa aa aa 5a 66 96 95 1e ef ff fa b6 b6 9a ec a8 d6 b5 5d 55 36 a6 cd a8 96 d6 ac 9f 2b 6c dd a1 2a 2a b5 7c a2 24 8b aa | -30 CRC error

    07:45:15.572 | aa aa aa aa aa aa aa aa aa aa aa aa aa 66 66 66 65 55 aa a9 aa 95 aa aa aa aa aa aa aa aa aa 5a aa 9a 5a aa aa a9 66 aa 65 59 59 a5 95 6a 99 56 9a 99 9a 6a 65 99 96 96 a6 a5 96 aa aa aa aa 5a 66 96 95 3e d7 ff ae ff 5a 6d be 6f 4d d5 54 ab 4d 56 4b 55 69 2a d8 92 4a 25 cb d6 a7 ed aa 46 eb 52 ab 65 | -30 CRC error

    07:45:16.588 | aa aa aa aa aa aa aa aa aa aa aa aa a9 99 99 99 95 56 aa a6 aa 56 aa aa aa aa aa aa aa aa a9 6a aa 69 6a aa aa a5 9a a9 95 65 66 96 55 aa 65 5a 6a 66 69 a9 96 66 5a 5a 9a 96 5a aa aa aa a9 69 9a 5a 54 bf 5b 5b 3a aa ba aa e1 55 10 ad 35 df 0d 2a 9b 55 6a 8b 52 1a ae d5 1b 76 63 29 ae b6 b1 c8 a6 55 | -30 CRC error

    07:45:17.962 | aa aa aa aa aa aa aa aa aa aa aa aa aa 99 99 99 99 55 6a aa 6a a5 6a aa aa aa aa aa aa aa aa 96 aa a6 96 aa aa aa 59 aa 99 56 56 69 65 5a a6 55 a6 a6 66 9a 99 66 65 a5 a9 a9 65 aa aa aa aa 96 99 a5 a5 4f d7 5b 33 d7 23 ae b2 b5 70 4d 3d ad ed 59 aa be a5 e5 42 55 11 71 b6 d6 ca b1 98 dc 89 49 ae 1c | -28 CRC error

    My registers

    IOCFG2 06

    SYNC3 aa

    SYNC2 aa

    SYNC1 aa

    SYNC0 ab

    SYNC_CFG1 a8

    DEVIATION_M 89

    MODCFG_DEV_E 0a

    DCFILT_CFG 5d

    PREAMBLE_CFG0 8a

    IQIC cb

    CHAN_BW 87

    MDMCFG1 40

    MDMCFG0 05

    SYMBOL_RATE2 84

    SYMBOL_RATE1 7a

    SYMBOL_RATE0 e1

    AGC_CS_THR ec

    AGC_CFG1 51

    AGC_CFG0 87

    FIFO_CFG 00

    FS_CFG 14

    PKT_CFG2 00

    PA_CFG0 54

    PKT_LEN 64

    IF_MIX_CFG 1c

    FREQOFF_CFG 22

    FREQ2 56

    FREQ1 af

    FREQ0 1a

    IF_ADC1 ee

    IF_ADC0 10

    FS_DIG1 07

    FS_DIG0 af

    FS_CAL1 40

    FS_CAL0 0e

    FS_DIVTWO 03

    FS_DSM0 33

    FS_DVC0 17

    FS_PFD 00

    FS_PRE 6e

    FS_REG_DIV_CML 1c

    FS_SPARE ac

    FS_VCO0 b5

    XOSC5 0e

    XOSC1 03

    PARTNUMBER 20

    PARTVERSION 11

    MODEM_STATUS1 10

     

  • Prodigy 287125 points

    In reply to Bryce Smith1:

    The sync word in your network is not a good sync word seen from the CC1200 side. Minimum would be to tun on strict sync (SYNCC_CFG0.STRICKT_SYNC_CHECK = 0x10) to be able to detect the start of the packet.

    Have you set AGC_REF according to your RX BW?

    Looking at what you receive and based on the sync word: Does the old network use manchester coding?

     

  • In reply to TER:

    Hi Ter

    Thank you again. 

    I have set "02 : Strict sync word check level 1" (I have tried all modes, it is now locking on in about 80% of cases to something. There is more consistency). During this I found out that my Sync bits where upside down, so the Preamble is actually 0x55... (instead of 0xAA...) And Sync is now 55,55,55,54 (unless it is this way even setting 1 will not work). 

    As my RX Filter BW is 60Khz I have set the AGC_REF from the default of 0x36 to 0x27

    On your question on Manchester encoding. I understand it is not, but I do have a doubt here. I have experimented with it and the data does not look right in that mode either. I think the first step is of course to get the consistency up. For the same packet I should see the same bytes. 

    I ask here about settings for absolute levels in the RF chain for bit 1 and bit 0, also about RF bitrate tolerances. 

    Here is what I picked up...

    08:26:58.047 | cc cc cc ca ab 55 53 55 2b 55 55 55 55 55 55 55 55 54 b5 55 34 b5 55 55 52 cc b4 d2 b5 34 b4 b3 53 33 4d 4c d2 ca ad 2b 2b 54 ad 35 4d 35 55 55 55 55 2a ac d3 34 3d 3f f5 b5 45 97 eb fb 5e a7 d5 e8 7a b9 8e 7d 78 e7 fd f5 fd ef 77 e5 ff bd bf 7d e5 f5 bb e9 fa fe fb 9c 3f f5 8c 77 23 e4 fd dd 6a d7 3b f1 ed 5e fb dd 7a ff 76 b1 12 aa ad b5 e5 ca 6c a9 59 12 8c 69 bf 53 55 ac 50 59 57 c9 51 92 52 91 54 88 a2 9c fa a1 42 8e a6 24 a0 6a d2 25 1a 48 c6 d5 57 96 09 47 51 dd 75 55 57 54 8c 6d d1 6d 03 12 fa d6 ad a5 51 04 d5 eb 6a 6c b4 2c da 42 94 75 6b 5a f5 3b 14 a5 a7 4a b5 b6 d6 7a 5a aa d0 29 b5 2d 52 2a c9 4c eb 35 5d c5 aa 54 a2 a3 67 ea 5a 9a 25 ac 2a d4 df ca 7a b5 f6 ae a4 b5 33 f5 6a 8c a4 29 a5 55 de db 50 aa 91 29 5d 12 35 59 55 d4 6a ae d1 b2 | -41 CRC error

    08:26:59.114 | cc cc cc ca ab 55 53 55 2b 55 55 55 55 55 55 55 55 54 b5 55 34 b5 55 55 52 cc b4 d2 b5 34 b4 b3 53 33 4d 4c d2 ca ad 2b 2b 54 ad 35 4d 35 55 55 55 55 2a ac d3 34 5e de ae f2 af 75 72 e3 57 6d b9 5b 2b 55 5a 91 55 56 b5 a9 2a 56 aa a7 76 6a d6 b4 95 95 b9 75 35 55 65 4e 59 53 5b aa aa aa b5 51 68 a8 e4 d3 36 ae d1 d5 5a 5a b5 56 b5 6a a9 12 ab 5e 9a 4a 69 94 8d 45 67 4b 2c a2 a7 2b 67 eb 55 11 52 a5 49 29 c6 a4 bd a9 55 58 29 2a aa a9 65 d3 52 35 1a aa d9 1b 29 93 4d 35 55 6b 4c ed ab 25 66 16 d5 a5 4e 48 1a 2d ab 0f 57 55 85 31 82 2c d6 4d 51 aa d2 48 7a b6 d6 d9 29 0a 6d 2e ad 6b 58 aa de 55 6e b5 6c cb 79 28 a9 55 ac 35 31 bf 55 b1 55 6e 92 4a 1c ae ed 1a a5 2d 3b ff 5f 3b bb ef 5b 3d 55 5a f6 ea 30 b9 55 9f c7 c9 5c d7 ac 4b ca c7 d0 ab 54 2a b5 95 | -42 CRC error

    08:27:00.200 | cc cc cc ca ab 55 53 55 2b 55 55 55 55 55 55 55 55 54 b5 55 34 b5 55 55 52 cc b4 d2 b5 34 b4 b3 53 33 4d 4c d2 ca ad 2b 2b 54 ad 35 4d 35 55 55 55 55 2a ac d3 34 7f bd e9 7b dd 5d 35 f9 6b 56 b6 b6 af d5 a5 29 36 e5 52 2a a8 55 52 b3 42 c9 6b a5 5b 3a aa b7 eb 4d ae ab 2d 55 49 0a 92 a4 9a aa 6a b2 b9 35 a6 ad c2 5c ad 75 44 1a ea b6 50 b3 2a d5 d5 55 65 8d ad a5 ea 9e 99 52 be 89 84 35 54 aa c4 a5 42 ad 62 5d 2a a5 6a ab 6a d0 97 05 25 53 41 55 d5 56 eb 6b 76 7a ad 6f 3d ad 64 ba 92 ec 71 a5 59 05 5a 5a d5 2d 42 ba d5 95 2a 62 aa c4 54 d5 2c 11 2d fa cf 9f 57 55 b5 a8 a9 01 58 ca 45 ea d5 ae ca bd fb ef 5e d8 cd cb f5 97 ba 45 ba e8 ed 55 31 34 35 f6 b1 27 f5 aa 77 2f 36 68 95 bb d7 34 d2 a9 3a ea cf 5b d7 17 2a fa 88 ca 0d 52 a8 52 ca 11 42 9d df a3 | -42 CRC error

    08:27:01.604 | cc cc cc ca ab 55 53 55 2b 55 55 55 55 55 55 55 55 54 b5 55 34 b5 55 55 52 cc b4 d2 b5 34 b4 b3 53 33 4d 4c d2 ca ad 2b 2b 54 ad 35 4d 35 55 55 55 55 2a ac d3 34 3f 5e b3 7b 69 ff 7d ad 6b 53 5f 75 6b 52 a9 97 6e d5 ad 6a 2a 8d bb 50 a5 42 55 59 4d 96 b6 92 54 e4 94 b7 55 a9 78 b5 2b 44 aa ac 2a aa 6a 86 d4 5b a4 50 95 45 65 ab d5 bc db 7a cb 7f 7d 6b ba ba d5 6a 36 b8 5e b2 b9 52 dd 5b 75 ab 56 8d 2a b1 22 2a fd 5b aa de c0 a7 ea fd ea a5 36 95 69 53 74 b6 cd 6d 71 6d 52 e5 36 ae 15 c3 6b 55 57 55 fa a6 fb 5e b2 da 6e bf 54 ab 62 80 aa aa ab d4 99 d3 4b af ed 54 a2 ae 55 d4 d1 54 a9 55 a9 55 4a ea d4 cd 56 12 5e 52 5a d1 aa d7 26 cd b5 ac ab 9b 55 b5 4b 4d 55 34 b2 91 b6 18 b4 44 ba b5 49 54 b7 56 a7 96 ea ab 25 49 d5 7b 8b 55 a5 5a a5 ca ca 56 64 76 | -42 CRC error

    08:27:02.886 | aa b3 4c d1 eb 7f 76 6f e1 28 ba c4 ac b0 5a 92 aa aa b0 aa d1 fb 45 ac 94 ab 47 16 a3 28 a9 54 6d e5 47 56 a5 d1 2b 48 aa 04 72 f4 53 2e d5 22 d5 62 ac de 4a aa bb 49 3b 25 42 d6 a1 4a aa a3 52 9a ad 6d 55 45 4a 95 55 4a 48 aa aa 6b 6b 4b aa b5 62 ae bd 53 dd 6b 44 85 ab 6c a8 96 ad 21 b4 a7 2a 94 ad 48 55 52 aa d4 8b 56 c5 a9 29 75 49 55 6a 9a 21 01 54 ee ec 53 d2 56 1a d5 b9 4a b5 a6 1a ab 49 a7 56 b6 cb 5b 5a 6e f0 b4 aa 55 68 28 ac 9d 56 a3 26 d2 5d b3 cc d5 54 82 94 ab 29 21 a8 a3 75 54 f9 83 6d 79 7d 57 6a a6 d2 7a ad 5a aa b2 95 2a a3 d2 54 1b 34 2d 14 54 48 d5 b5 95 51 6b 38 c9 97 55 55 4b 6a ac ad 89 34 6e 53 94 55 56 b5 b1 a9 d4 aa b4 4c 4e 44 e9 89 f6 b9 9f b3 eb eb 0b 6d 52 2e 9a c7 2d 2a 82 a9 32 60 aa fd de 9f b5 48 d0 2e 74 d3 56 b5 31 | -42 CRC error

    08:27:03.934 | cc cc cc ca ab 55 53 55 2b 55 55 55 55 55 55 55 55 54 b5 55 34 b5 55 55 52 cc b4 d2 b5 34 b4 b3 53 33 4d 4c d2 ca ad 2b 2b 54 ad 35 4d 35 55 55 55 55 2a ac d3 34 3b fb 5a b7 46 ea d5 2c 29 a2 9d 35 cd a9 52 15 2b ba ba 64 d8 ab d4 ab b6 84 2a a6 2c d2 c4 d0 52 d1 46 52 a9 55 6a 5a 51 76 55 0b 6a 2a a7 7f f5 6c 5e ed ab 0a 89 65 ad 4b 52 d5 9b 37 57 c0 a6 da ed 52 ab 6e a5 1a a5 3a 8a 57 4a 85 54 97 34 ed 2b 62 ba 9b 9f 28 6a d6 aa 9a d6 da 7d eb a5 2c 52 a1 64 5a aa 85 50 ab c8 19 2a 3a 92 6a 35 52 ac 4d ad 19 da a9 b6 ef 85 97 a5 49 4a b4 b2 91 aa ab 1d 62 ba a4 92 6a a2 2b 4d a0 ae 89 8b f8 d5 86 d1 55 a2 56 4d 4a b3 94 55 76 b5 31 55 a4 d4 2d a3 5a ad 4f 65 a2 52 d4 ad 62 b6 ea d7 5c b5 99 57 ea 5d 7d b6 2e 2c d2 98 a2 a9 31 ab 19 53 07 a6 b6 52 b4 | -42 CRC error

    My registers are:

    IOCFG2 06

    SYNC3 55

    SYNC2 55

    SYNC1 55

    SYNC0 54

    SYNC_CFG1 a8

    SYNC_CFG0 02

    DEVIATION_M 89

    MODCFG_DEV_E 0a

    DCFILT_CFG 5d

    PREAMBLE_CFG0 8a

    IQIC cb

    CHAN_BW 87

    MDMCFG1 40

    MDMCFG0 05

    SYMBOL_RATE2 84

    SYMBOL_RATE1 7a

    SYMBOL_RATE0 e1

    AGC_REF 27

    AGC_CS_THR ec

    AGC_CFG1 51

    AGC_CFG0 87

    FIFO_CFG 00

    FS_CFG 14

    PKT_CFG2 00

    PA_CFG0 54

    PKT_LEN fe

    IF_MIX_CFG 1c

    FREQOFF_CFG 22

    FREQ2 56

    FREQ1 af

    FREQ0 1a

    IF_ADC1 ee

    IF_ADC0 10

    FS_DIG1 07

    FS_DIG0 af

    FS_CAL1 40

    FS_CAL0 0e

    FS_DIVTWO 03

    FS_DSM0 33

    FS_DVC0 17

    FS_PFD 00

    FS_PRE 6e

    FS_REG_DIV_CML 1c

    FS_SPARE ac

    FS_VCO0 b5

    XOSC5 0e

    XOSC1 03

    PARTNUMBER 20

    PARTVERSION 11

    MODEM_STATUS1 10

    Kind regards

    Bryce

  • Prodigy 287125 points

    In reply to Bryce Smith1:

    Meaning that you don't have full overview over the settings used in the original network? 

     

  • In reply to TER:

    Hello Ter

    Just to clarify, I do have a full overview, but the program used by the other manufacturers setting program is a bit buggy. Manchester encoding is set to off, however after looking at the RF data, I do have a doubt about it. 

    Kind regards

  • Prodigy 287125 points

    In reply to Bryce Smith1:

    Ok, I will wait until you have double checked all settings. When you are sure that what is shown in the GUI of the setup program is the same as you have on the air, could you post a screenshot of the setup? 

     

  • In reply to TER:

    Hello Ter

    I'm sorry for any confusion. The settings I have given are the setting I believe they are. There was a bug in their setup tool (the other IC manufacture) with another setting. An therefore I have lost some confidence with it. However the settings are what I have given you (assuming the tool is working correctly). I'm just trying to give you as much information as possible, without giving you settings that would be confusing or side-track this. The "old" network has never had to be interfaced to another manufacturers IC before, so this has never come up. 

    Can we please proceed as is? At the very least Manchester coding or not, the data should be consistent. Its more of a secondary point, or next stage problem, I would think? I don't think there are any other settings relevant to the TI solution. If I haven't given you something in the RX chain that may be needed then please let me know. I know that I am using data whitening for example, but again the data should at least be consistent. I think the first step is to at least get consistent RX data. Though, thanks to you, we have made great progress in that area already. 

    Kind regards

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