Dear TI Engineers,
I have gathered vital signs data using the configurations provided below when the subject was sitting at a 43cm distance. However, I'm encountering difficulties in generating the frequency signal after applying a bandpass filter and getting a wrong time than the mmwave log file shown values using a sampling rate of 6e6. I think I am using the wrong parameters and units. Your support in resolving the issues outlined below would be greatly appreciated.
- When the sampling rate is 6e6, the achieved range is 0.43 meters, which seems a correct range value. However, I am unable to plot data for the frequencies 0.1 to 0.2 or 0.4Hz using a Bandpas filter and getting the wrong time values(0.04 seconds). I used Time = np.arange(0, len(signal) / Fs_adc, 1/Fs_adc) to generate the time, where "signal" is the collected data, Fs_adc is the sampling rate. I used the X-axis for time and Y axis for amplitude. Kindly see the attached file for the pic. May I know why I am getting the wrong time values and unable to generate a plot for the mentioned frequencies?
- I changed a sampling rate of 6e6 to 6000 to see the behavior for data analysis, which gave me 0.00043 meters for range and time of 52 seconds, and I was also able to generate a plot for the mentioned frequencies. May I know what exact sampling rate values and parameter units should be used?
- Why does the time indicated in the mmwave studio log file differ from the time calculated by dividing the number of samples by the sampling rate?
- Number of frames (n_frame) = 2326
- Chirps per frame (chirp_per_frame) = 128
- Frame periodicity (frame_periodicity) = 25.8 milliseconds
- Wait before copy (wait_before_copy) = 70000
- Starting frequency (start_freq) = 77 GHz
- Idle time (idle_time) = 150 microseconds
- ADC start time (adc_start_time) = 6 microseconds
- Ramp end time (ramp_end_time) = 50 microseconds
- Frequency slope (freq_slope) = 80MHz/Microsecond
- ADC samples (adc_samples) = 256
- ADC sample rate (adc_sample_rate) = 6000ksps
- RX gain (RX_gain) = 30 dB
Best
Deepu
