3.6.3. Spectrum analyzer utility
The Red Pitaya spectrum analyzer utility is a command-line tool that enables the measurement of the frequency spectrum of the input signal. The utility can be used to set the minimum and maximum frequency, the iteration count, and the window function. The utility can also be used to enable or disable averaging and to print the values in CSV format. The spectrum utility
redpitaya> spectrum -h
spectrum Version: 2.07-651-631657660
usage:
-h, --help: help
-m, --min: minimum frequency (default: 0)
-M, --max: maximum frequency (default: 62500000)
-c, --count: iteration count (default: 1, negative: infinity)
-a, --average: average the measurement from 10 times (default: enabled)
-n, --no-average: disable average the measurement from 10 times
-v, --values: Display all values for the signal.
-C, --csv: print values by columns Frequency (Hz), ch0 (dB), ch1 (dB)
-L, --csv-limit: print values by columns Frequency (Hz), ch0 min (dB), ch0 max (dB), ch1 min (dB), ch1 max (dB)
-W, --window: window function. Available options: [rect, hanning, hamming, blackman_harris, flat_top, kaiser_4, kaiser_8] (default: hanning)
-t, --test: test mode avoids the initiating/resetting/releasing FPGA
Examples:
redpitaya> spectrum -m 5000 -M 20000 -c 10
ch0 peak: 9994.14 Hz, -5.66 dB
ch1 peak: 14991.21 Hz, -5.98 dB
ch0 peak: 9994.14 Hz, -5.66 dB
ch1 peak: 14991.21 Hz, -5.98 dB
ch0 peak: 9994.14 Hz, -5.66 dB
ch1 peak: 14991.21 Hz, -5.98 dB
ch0 peak: 9994.14 Hz, -5.66 dB
ch1 peak: 14991.21 Hz, -5.98 dB
ch0 peak: 9994.14 Hz, -5.66 dB
ch1 peak: 14991.21 Hz, -5.98 dB
ch0 peak: 9994.14 Hz, -5.66 dB
ch1 peak: 14991.21 Hz, -5.98 dB
ch0 peak: 9994.14 Hz, -5.66 dB
ch1 peak: 14991.21 Hz, -5.98 dB
ch0 peak: 9994.14 Hz, -5.66 dB
ch1 peak: 14991.21 Hz, -5.98 dB
ch0 peak: 9994.14 Hz, -5.66 dB
ch1 peak: 14991.21 Hz, -5.98 dB
ch0 peak: 9994.14 Hz, -5.66 dB
ch1 peak: 14991.21 Hz, -5.98 dB
ch0 peak summary: 9994.14 Hz, -5.66 dB
ch1 peak summary: 14991.21 Hz, -5.98 dB
redpitaya> spectrum -m 5000 -M 20000 -C
Frequency (Hz), ch0 (dB), ch1 (dB)
4997.07, -82.60, -82.13
5004.52, -85.25, -85.39
5011.96, -96.31, -92.84
5019.41, -98.83, -93.82
5026.86, -95.01, -88.88
5034.31, -92.14, -86.11
5041.75, -92.64, -89.86
5049.20, -97.11, -97.61
5056.65, -101.76, -96.45
5064.09, -90.20, -99.99
...
19936.15, -91.16, -103.93
19943.60, -94.67, -103.84
19951.04, -110.36, -90.97
19958.49, -98.84, -90.27
19965.94, -94.09, -96.89
19973.38, -93.11, -102.65
19980.83, -87.56, -96.00
19988.28, -80.81, -89.86
19995.73, -82.90, -91.80
20003.17, -90.31, -95.15
redpitaya> spectrum -m 5000 -M 20000 -L -c 10
Frequency (Hz), ch0 min (dB), ch0 max (dB), ch1 min (dB), ch1 max (dB)
4997.07, -86.13, -79.79, -84.41, -80.12
5004.52, -88.61, -85.56, -91.46, -82.50
5011.96, -101.85, -87.46, -109.80, -87.67
5019.41, -99.89, -87.81, -100.97, -85.96
5026.86, -102.96, -85.72, -105.65, -85.56
5034.31, -97.97, -86.37, -106.42, -89.44
5041.75, -98.22, -86.68, -113.84, -87.04
5049.20, -112.02, -87.81, -109.86, -85.26
5056.65, -102.35, -87.70, -100.77, -87.54
5064.09, -103.42, -87.38, -104.93, -89.51
...
19936.15, -114.66, -84.41, -99.82, -83.39
19943.60, -106.68, -88.86, -100.68, -84.00
19951.04, -103.79, -89.17, -112.73, -88.91
19958.49, -100.00, -85.89, -107.91, -88.63
19965.94, -110.12, -90.15, -113.49, -87.20
19973.38, -103.56, -87.70, -100.68, -86.50
19980.83, -103.51, -82.43, -102.41, -86.18
19988.28, -82.96, -77.75, -95.58, -84.13
19995.73, -87.12, -79.13, -98.90, -82.72
20003.17, -101.35, -87.47, -106.83, -88.50
To run the spectrum analyzer utility, perform the following steps:
Load the FPGA image.
redpitaya> overlay.sh v0.94redpitaya> cat /opt/redpitaya/fpga/fpga_0.94.bit > /dev/xdevcfgStart the console application.
redpitaya> spectrum -m 5000 -M 20000 -c 10 ch0 peak: 9994.14 Hz, -5.66 dB ch1 peak: 14991.21 Hz, -5.98 dB ch0 peak: 9994.14 Hz, -5.66 dB ch1 peak: 14991.21 Hz, -5.98 dB ch0 peak: 9994.14 Hz, -5.66 dB ch1 peak: 14991.21 Hz, -5.98 dB ch0 peak: 9994.14 Hz, -5.66 dB ch1 peak: 14991.21 Hz, -5.98 dB ch0 peak: 9994.14 Hz, -5.66 dB ch1 peak: 14991.21 Hz, -5.98 dB ch0 peak: 9994.14 Hz, -5.66 dB ch1 peak: 14991.21 Hz, -5.98 dB ch0 peak: 9994.14 Hz, -5.66 dB ch1 peak: 14991.21 Hz, -5.98 dB ch0 peak: 9994.14 Hz, -5.66 dB ch1 peak: 14991.21 Hz, -5.98 dB ch0 peak: 9994.14 Hz, -5.66 dB ch1 peak: 14991.21 Hz, -5.98 dB ch0 peak: 9994.14 Hz, -5.66 dB ch1 peak: 14991.21 Hz, -5.98 dB ch0 peak summary: 9994.14 Hz, -5.66 dB ch1 peak summary: 14991.21 Hz, -5.98 dB
Source code
The Red Pitaya GitHub repository contains the source code for the spectrum utility.