CC1120: Noise in packet RF send.

Nguyen Minh Vu

Intellectual 730 points

Part Number: CC1120

Hi TI supporters!

I use cc1120 to transmit data:

-4bytes Preamble(0xAA) + 4 bytes sync(0x07) + payload(10byte)

Payload is:

        tx_rf_buff[0] = 0x09;
	tx_rf_buff[1] = 0x0F;	// serial number 1-6
	tx_rf_buff[2] = 0x0F;
	tx_rf_buff[3] = 0x0F;
	tx_rf_buff[4] = 0x0F;
	tx_rf_buff[5] = 0x0F;
	tx_rf_buff[6] = 0x0F;
	tx_rf_buff[7] = 0x0F;	// Mode 00 - PTT, 01 - sensor
	tx_rf_buff[8] = 0x0F;	// Battery data 00-FF
	tx_rf_buff[9] = 0x0F;

When I send this packet, end of each packet have a noise pulse. I don't know what is this. This noise make frequency diviation is increase.

Can you help me fix this problem?

Thank you!

Vu.

over 5 years ago

0 RGW over 5 years ago

TI__Mastermind 33520 points

Hi,

Which hardware are you measuring this on ?

Regards,

Richard

0 Nguyen Minh Vu over 5 years ago in reply to RGW

Intellectual 730 points

Hi Richard!

I'm running on my custom hardware.

Vu.

0 Nguyen Minh Vu over 5 years ago in reply to RGW

Intellectual 730 points

Hi,

I set TXOFF_MODE = 10b (TX).

It look like TX is off when packet TX finished successfully. In this moment, TX power is 0mW.

When I change setting PA_CFG(related PA ramping) this noise pulse is change.

Do you have any idea?

Vu.

0 TER over 5 years ago in reply to Nguyen Minh Vu

TI__Guru**** 317180 points

Please provide the settings you are using, ideally as a SmartR Studio .cfg file.

0 Nguyen Minh Vu over 5 years ago in reply to TER

Intellectual 730 points

Hi TER!

My config:

IOCFG3	0xB0
IOCFG2	0x06
IOCFG1	0xB0
IOCFG0	0x02
SYNC3	0x93
SYNC2	0x0B
SYNC1	0x51
SYNC0	0xDE
SYNC_CFG1	0x0B
SYNC_CFG0	0x17
DEVIATION_M	0x90
MODCFG_DEV_E	0x01
DCFILT_CFG	0x1C
PREAMBLE_CFG1	0x18
PREAMBLE_CFG0	0x2A
FREQ_IF_CFG	0x40
IQIC	0xC6
CHAN_BW	0x08
MDMCFG1	0x46
MDMCFG0	0x05
SYMBOL_RATE2	0x43
SYMBOL_RATE1	0xA9
SYMBOL_RATE0	0x2A
AGC_REF	0x20
AGC_CS_THR	0x19
AGC_GAIN_ADJUST	0x00
AGC_CFG3	0x91
AGC_CFG2	0x20
AGC_CFG1	0xA9
AGC_CFG0	0xC3
FIFO_CFG	0x00
DEV_ADDR	0x00
SETTLING_CFG	0x0B
FS_CFG	0x14
WOR_CFG1	0x08
WOR_CFG0	0x21
WOR_EVENT0_MSB	0x00
WOR_EVENT0_LSB	0x00
PKT_CFG2	0x04
PKT_CFG1	0x00
PKT_CFG0	0x20
RFEND_CFG1	0x0F
RFEND_CFG0	0x20
PA_CFG2	0x7F
PA_CFG1	0x56
PA_CFG0	0x7C
PKT_LEN	0xFF
IF_MIX_CFG	0x00
FREQOFF_CFG	0x22
TOC_CFG	0x0B
MARC_SPARE	0x00
ECG_CFG	0x00
CFM_DATA_CFG	0x00
EXT_CTRL	0x01
RCCAL_FINE	0x00
RCCAL_COARSE	0x00
RCCAL_OFFSET	0x00
FREQOFF1	0x00
FREQOFF0	0x00
FREQ2	0x6A
FREQ1	0x90
FREQ0	0x00
IF_ADC2	0x02
IF_ADC1	0xA6
IF_ADC0	0x04
FS_DIG1	0x00
FS_DIG0	0x5F
FS_CAL3	0x00
FS_CAL2	0x20
FS_CAL1	0x40
FS_CAL0	0x0E
FS_CHP	0x28
FS_DIVTWO	0x03
FS_DSM1	0x00
FS_DSM0	0x33
FS_DVC1	0xFF
FS_DVC0	0x17
FS_LBI	0x00
FS_PFD	0x50
FS_PRE	0x6E
FS_REG_DIV_CML	0x14
FS_SPARE	0xAC
FS_VCO4	0x14
FS_VCO3	0x00
FS_VCO2	0x00
FS_VCO1	0x00
FS_VCO0	0xB4
GBIAS6	0x00
GBIAS5	0x02
GBIAS4	0x00
GBIAS3	0x00
GBIAS2	0x10
GBIAS1	0x00
GBIAS0	0x00
IFAMP	0x01
LNA	0x01
RXMIX	0x01
XOSC5	0x0E
XOSC4	0xA0
XOSC3	0x03
XOSC2	0x04
XOSC1	0x03
XOSC0	0x00
ANALOG_SPARE	0x00
PA_CFG3	0x00
WOR_TIME1	0x00
WOR_TIME0	0x00
WOR_CAPTURE1	0x00
WOR_CAPTURE0	0x00
BIST	0x00
DCFILTOFFSET_I1	0x00
DCFILTOFFSET_I0	0x00
DCFILTOFFSET_Q1	0x00
DCFILTOFFSET_Q0	0x00
IQIE_I1	0x00
IQIE_I0	0x00
IQIE_Q1	0x00
IQIE_Q0	0x00
RSSI1	0x80
RSSI0	0x00
MARCSTATE	0x41
LQI_VAL	0x00
PQT_SYNC_ERR	0xFF
DEM_STATUS	0x00
FREQOFF_EST1	0x00
FREQOFF_EST0	0x00
AGC_GAIN3	0x00
AGC_GAIN2	0xD1
AGC_GAIN1	0x00
AGC_GAIN0	0x3F
CFM_RX_DATA_OUT	0x00
CFM_TX_DATA_IN	0x00
ASK_SOFT_RX_DATA	0x30
RNDGEN	0x7F
MAGN2	0x00
MAGN1	0x00
MAGN0	0x00
ANG1	0x00
ANG0	0x00
CHFILT_I2	0x08
CHFILT_I1	0x00
CHFILT_I0	0x00
CHFILT_Q2	0x00
CHFILT_Q1	0x00
CHFILT_Q0	0x00
GPIO_STATUS	0x00
FSCAL_CTRL	0x01
PHASE_ADJUST	0x00
PARTNUMBER	0x00
PARTVERSION	0x00
SERIAL_STATUS	0x00
MODEM_STATUS1	0x01
MODEM_STATUS0	0x00
MARC_STATUS1	0x00
MARC_STATUS0	0x00
PA_IFAMP_TEST	0x00
FSRF_TEST	0x00
PRE_TEST	0x00
PRE_OVR	0x00
ADC_TEST	0x00
DVC_TEST	0x0B
ATEST	0x40
ATEST_LVDS	0x00
ATEST_MODE	0x00
XOSC_TEST1	0x3C
XOSC_TEST0	0x00
RXFIRST	0x00
TXFIRST	0x00
RXLAST	0x00
TXLAST	0x00
NUM_TXBYTES	0x00
NUM_RXBYTES	0x00
FIFO_NUM_TXBYTES	0x0F
FIFO_NUM_RXBYTES	0x00

Thank for reply!

Vu.

0 RGW over 5 years ago in reply to Nguyen Minh Vu

TI__Mastermind 33520 points

Hi,

Have you tested with TXOFF_MODE = 00b

Have you tested with the default settings in SmartRF studio with the Generic 434 MHz, 1.2 kbps, 2-FSK, RX BW 25 kHz PHY ?

Regards,

Richard

Sub-1 GHz

Sub-1 GHz forum

CC1120: Noise in packet RF send.