Question for testing the receive mode of CC1101 with TrxEB

Hi

The 1.2 kHz signal you see is the clock as the default data rate when opening studio is 2.3 kbps.

You do not say anything about which EM you are using. I did the same thing as you describe and were able to see both data and clock on GDO0 and GDO2. I used an 868 MHz EM and used the default frequency. If I used the same EM and changed the frequency to 403, the clock was still running at 1.2 kHz but the data line was high most of the time.

If you have an 868 MHz, can you do the test at 868 MHz and see if it works OK then?

Siri

Dear sir,

Thank you for your fast response.

I have 433MHz module and the default data rate of SmartRF studio is 1.2KBaud on generic 868MHz.

(There is no menu of 433MHz for cc1101 on RFsmart studio)

I only changed the 868MHz of base frequency to 403MHz.

Anyway, you mean that 1.2KHz is clock and data line will be high mostof time.

So, i thknk that when will the data line be low?

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I did the addtional testing with signal generator.

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1. Amplitude value of signal generator was changed from -50dBm to -90 by 5 steps.

2. I changed the value to -90dBm and then i found that data line is low.

3. I changed the value to -95dBm and then i found that data line is continuously changed from high to low.

4. i think that the sensitivty of this module is -95dBm.

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** Here's my question:

1. is it right that the sensitivity of this module is -95dBm. at the default parameter.(only changed 403MHz)

2. i think that data line is output of demodulated data. why is it not changed until RSSI value reach the limit?

Best & Regards,

I did a brief test with 2 CC1101 433 EMs running @403 MHz. The Tx side is set to send random data, on the Rx side I see that the data line has a few transitions even if the sender is off and when the RSSI is around -70 dBm (random test value) it looks like I receive what I would expect to receive.

The sensitivity for the module is stated in the datasheet.

Dear sir,

Thank you for your reply.

what I want to test is the RF sensitivity with oscilloscope + signal generator + RFsmart studio + EM.

I need that the RFsmart studio is to set the register(GPIO2, GPIO0) and signal generator is to produce the RF modulation signal. and oscilloscpoe is to check the RF sensitivity(demodulated signal).

I think that if the data rate of signal generator is 1.2KHz, the wave of oscilloscope must be 1.2KHz

This is the clock signal. i found that it's ok.                                           

I want to check the demodulated signal from the output of CC1101, but i could not find the transition signal.

if the amplitude of the signal generator is -50dBm, i think that the data line(demodulated signal) is continuously changed from high to low and the wave must be rectangle wave.

But, even if the amplitude of the signal generator is -50dBm, data line reamined the high.

After i check it, i changed the -50dBm to -60,-70,-80 and-90dBm. it still remain the high.

Here's my question: Why was the data line  not changed? when will it be changed?

Finally, i changed the -90dBm to -95dBm and then i found the data line was continuously high, low,high,low.

So, what i want to know is that the data line remains the high signal if the amplitude of signal generator is within the sensitivity limit of CC1101. But, if the amplitude value of signal generator is out of range the sensitivity limit of CC01,data line will be changed from high to low continuously.

is it right what i think above?

That is, how do i check the RF sensitivity of CC1101 module with both GPIO data line and oscilloscpoe?

B&R

Could you clarify something for me: In your first post it sounded like you were sending modulated data with your signal generator but reading your last post it sounds like you are sending a CW?

Dear sir,

I'm sorry that i make you confused.

I were sending the modulated data with signal generator and then the TI EM were were receving it.

And i want to check the demodulated signal with both GPIO and oscilloscope.

B&R

Is the modulated signal a '1010' sequence or random data? I want to recreate your set-up as close as possible.

Dear sir,

Thank u for your fast response.

I generated the sine wave on the signal generateor, it's not a binanary sequence.

This procedure is your sequence on your datasheet.

I want to know the testing method to test your CC1101 with osciilopscope.

If my testing method is not a proper, please give me the proper method to test with ocsilopscope.

I think that i followed your testing procedure on your datasheet.

But, i could not find the proper solution.

Sol, please give me your guideline a.s.a.p.

i think that you didn't undersntand my question .

What i want to know is that how do i test your module with oscillosco[e?

And then, when will the data line be changed?

Please, tell me that how do i know the sensitivity of the CC1101 with oscilloscopoe not RSSI on your RFsmart studo?

B&R

If you want to test sensitivity using a oscilloscope you need a signal generator that could give a "0101" sequence with the modulation you use on CC1101. Then, for high input power you will see the same sequence on the scope. Close to the sensitivity limit you will start to see bit errors.