FreeDV
/
pirip
mirror of https://github.com/drowe67/pirip.git
1
0
Fork 0
Code Issues Releases Wiki Activity

updated README for librtlsdr, repeated rtl_fsk OTB tests with HackRF

pull/2/head
David 2020-09-19 10:42:14 +09:30
parent ed2e913bda
commit 015ce55781
2 changed files with 6 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
README.md
View File

@ -58,7 +58,7 @@ $ ./build_rtlsdr.sh
```
1. Receive test frames on x86 laptop for 5 seconds (vanilla rtl_sdr):
```
~/pirip$ Fs=240000; rtl-sdr-blog/build_rtlsdr/src/rtl_sdr -g 49 -s $Fs -f 144490000 - | codec2/build_linux/src/fsk_demod --fsk_lower 500 --fsk_upper 25000 -d -p 24 2 240000 10000 - - | codec2/build_linux/src/fsk_put_test_bits -
~/pirip$ Fs=240000; librtlsdr/build_rtlsdr/src/rtl_sdr -g 49 -s $Fs -f 144490000 - | codec2/build_linux/src/fsk_demod --fsk_lower 500 --fsk_upper 25000 -d -p 24 2 240000 10000 - - | codec2/build_linux/src/fsk_put_test_bits -
1. Receive test frames on x86 laptop for 5 seconds (vanilla rtl_sdr at Fs=1.8MHz):
```
@ -67,16 +67,16 @@ $ ./build_rtlsdr.sh
```
1. Receive test frames on x86 laptop for 5 seconds (integrated rtl_fsk):
```
~/pirip$ Fs=240000; tsecs=5; ./rtl-sdr-blog/build_rtlsdr/src/rtl_fsk -g 49 -f 144490000 - -n $(($Fs*$tsecs)) | codec2/build_linux/src/fsk_put_test_bits -
~/pirip$ Fs=240000; tsecs=5; ./librtlsdr/build_rtlsdr/src/rtl_fsk -g 49 -f 144490000 - -n $(($Fs*$tsecs)) | codec2/build_linux/src/fsk_put_test_bits -
```
Note this is tuned about 10kHz low, to put the two tones above the rtl_sdr DC line.
1. Demod GUI Dashboard. Open a new console and start `demod_gui.py`:
1. Demod GUI Dashboard. Open a new console and start `dash.py`:
```
~/pirip$ netcat -luk 8001 | ./src/dash.py
```
In another console start the FSK demod:
```
~/pirip$ Fs=240000; tsecs=20; ./rtl-sdr-blog/build_rtlsdr/src/rtl_fsk -g 1 -f 144490000 - -n $(($Fs*$tsecs)) -u localhost | codec2/build_linux/src/fsk_put_test_bits -
~/pirip$ Fs=240000; tsecs=20; ./librtlsdr/build_rtlsdr/src/rtl_fsk -g 1 -f 144490000 - -n $(($Fs*$tsecs)) -u localhost | codec2/build_linux/src/fsk_put_test_bits -
```
![](doc/dash.png)
1. Automated loopback tests. Connect your Pi to your RTLSDR via a 60dB attenuator
@ -95,7 +95,7 @@ $ ./build_rtlsdr.sh
This example generates 1000 bit/s FSK with a 2000Hz shift:
```
cd codec2/build_linux/src
./fsk_get_test_bits - 60000 | ./fsk_mod -c -a 32767 2 40000 1000 1000 2000 - - | ../misc/tlininterp - t.iq8 100 -d -f
./fsk_get_test_bits - 60000 | ./fsk_mod -c -a 30000 2 40000 1000 1000 2000 - - | ../misc/tlininterp - t.iq8 100 -d -f
```
The output samples are at a sample rate of 4MHz, and a frequency offset of +1 MHz. They can be played out of the HackRF with:
```
@ -114,7 +114,7 @@ $ ./build_rtlsdr.sh
```
A few Octave plot windows will pop up. Adjust your signal generator frequency so the sine wave is between 2000 and 4000, the
script will print the Noise Figure (NF). Around 6-6.2 dB was obtained using RTL-SDR.COM V3s using"-g 50"
script will print the Noise Figure (NF). Around 6.5 dB was obtained using RTL-SDR.COM V3s using"-g 50"
See also codec2/octave/nf_from_stdio.m and [Measuring SDR Noise Figure in Real Time](http://www.rowetel.com/?page_id=6172).

BIN
doc/dash.png
View File

Binary file not shown.
Side by Side Swipe Overlay

Before

Width:  |  Height:  |  Size: 23 KiB

After

Width:  |  Height:  |  Size: 35 KiB