CC1101: Switching b/w Carrier(Unmodulated) and Modulated Wave on CC1101

Hassaan Shah

Part Number: CC1101

Dear All,

I have a query regarding whether I can switch between Unmodulated and Modulated Wave when radio is already working in one of the mode i.e either in unmodulated or modulated mode.

I am sending these commands at runtime through SPI:

For Unmodulated Wave:

CC1101_MDMCFG2_Setting_Value = 0x33; // ASK/OOK Modulation, Sync Word Used

CC1101_PKTCTRL0_Setting_Value = 0x12; //Sycnchronous Serial Mode,Infinite Packet Length

For Modulated Wave:

CC1101_MDMCFG2_Setting_Value = 0x03; //2-FSK Modulation, Sync Word Used

CC1101_PKTCTRL0_Setting_Value = 0x41; //TxFIFO Used, Variable Packet Length

Thank you

over 8 years ago

0 TER over 8 years ago

TI__Guru**** 317180 points

I believe you have to switch to IDLE before changing the mode.

Is it a specific reason you want to go directly from CW to modulated or the other way around?

0 Hassaan Shah over 8 years ago in reply to TER

Intellectual 340 points

Dear TER,
Yes, I am taking the radio into IDLE Mode before sending the desired commands through SPI. Am if missing something?. Thank you

0 TER over 8 years ago in reply to Hassaan Shah

TI__Guru**** 317180 points

Then I think I misunderstood your question. Don't you get it to work?

0 Hassaan Shah over 8 years ago in reply to TER

Intellectual 340 points

Dear TER,
Actually No, the Mode of modulation once set whether it is unmodulated or modulated it works. But again on runtime I try to change either of the mode it does not work on spectrum analyzer it is showing as 0 value....No peaks

0 TER over 8 years ago in reply to Hassaan Shah

TI__Guru**** 317180 points

Does e2e.ti.com/.../1537629 give you more information?

If you want to send modulated data you either have to fill the FIFO with something or to send random data (PN9 sequence) setting PKTCTRL0.PKT_FORMAT = 2 (I believe you have to put at least one byte into the TX FIFO to avoid sending preamble)

If you still have issues, please post more of your code and a spectrum plot showing the result for the different cases.

Sub-1 GHz

Sub-1 GHz forum

CC1101: Switching b/w Carrier(Unmodulated) and Modulated Wave on CC1101