CC1201: TX Strobe Time

Onur Sengoz

Part Number: CC1201
Other Parts Discussed in Thread: CC1312R

Hi,

I am working on CC120xEM 868/930 MHz board.

When I put 125 bytes of data to CC1201 buffer and send strobe TX command, it takes appr. 27ms for GPIO2 to become low from high. I guess, during this high state it sends the data, right? If so, isn't this duration too long ? Or is it normal? How can I reduce this duration?

Thanks..

over 7 years ago

0 TER over 7 years ago

TI__Guru**** 317180 points

You don't write which signal you have on GPIO2 nor the datarate you are using. Please provide.

0 Onur Sengoz over 7 years ago in reply to TER

Prodigy 100 points

Hi,

Configuration is: CC120X_IOCFG2, 0x06

Frequency: 868MHz

RX Filter BW: 98kHz

Modulation: 2-GFSK

Symbol Rate: 38.4 ksps

Deviation: 25 kHz

0 TER over 7 years ago in reply to Onur Sengoz

TI__Guru**** 317180 points

The description of the signal you are monitoring is the following:
"TX: Asserted when sync word has been sent, and de-asserted at the end of the packet"

Hence the time should be (125+2)*8/38.4e3 = 26.5 ms which is what you see.

0 Onur Sengoz over 7 years ago in reply to TER

Prodigy 100 points

In the system, CC1201 communicates with CC1312R. With the configuration above it works. But I want to shorten this 27ms by increasing symbol rate.

I am using smart RF Studio and I make symbol rate 100kBaud and RX filter BW 235.5kHz at CC1312 side.
At CC1201 side, I make Symbol rate 100ksps and when try to make RX filter BW 235.5, it automatically makes it 238.095238.

And this conf.s doesn't work. Any advice? Thanks..

0 TER over 7 years ago in reply to Onur Sengoz

TI__Guru**** 317180 points

"does not work": Is this the case both when CC1312 is TX and CC1201 is RX and visa versa?

On the CC1201 side, did you use the 100 kbps setting in SmartRF Studio?

0 Onur Sengoz over 7 years ago in reply to TER

Prodigy 100 points

Hi,
I solved it by;

CC1312R:
Frequency: 868MHz
RX Filter BW: 235.5kHz
Modulation: 2-GFSK
Symbol Rate: 100 kBaud
Deviation: 25 kHz

CC1201:
Frequency: 868MHz
RX Filter BW: 238.0kHz
Modulation: 2-GFSK
Symbol Rate: 100 ksps
Deviation: 25 kHz

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CC1201: TX Strobe Time