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updated build scripts for librtlsdr and use of csdr

pull/2/head
David 2020-09-19 09:36:58 +09:30
parent 74f0cdca6e
commit 3e34fa6ce8
3 changed files with 31 additions and 7 deletions
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24
README.md
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@ -6,7 +6,7 @@ Minimal hardware IP over VHF/UHF Radio using RpiTx and RTLSDRs [1].
# Project Plan and Status
Next step is to try some Over The Air (OTA) tests.
Currently working on M4 -Over The Air (OTA) tests.
| Milestone | Description |
| --- | --- |
@ -35,13 +35,14 @@ $ ./build_rpitx.sh
$ cd tx && make
```
## RTLSDR Receiver
## RTLSDR FSK Receiver
On your laptop/PC:
```
$ sudo apt update
$ sudo apt install libusb-1.0-0-dev git cmake
$ ./build_codec2.sh
$ ./build_csdr.sh
$ ./build_rtlsdr.sh
```
@ -96,11 +97,28 @@ $ ./build_rtlsdr.sh
hackrf_transfer -t t.iq8 -s 4E6 -f 143.5E6
```
The signal will be centred on 144.5 MHz (143.5 + 1 MHz offset).
1. Noise Figure Testing
Connect a signal generator to the input of the RTLSDR. Set the frequency to 144.5MHz, and amplitude to -100dBm.
The following command pipes the RTL output to an Octave script to measure noise figure. You need the CSDR tools and Octave installed:
```
$ cd ~/pirip/rtl-sdr-blog/build_rtlsdr/src
$ ./rtl_sdr -g 50 -s 2400000 -f 144.498E6 - | csdr convert_u8_f | csdr fir_decimate_cc 50 | csdr convert_f_s16 | octave --no-gui -qf ~/pirip/codec2/octave/nf_from_stdio.m 48000 complex
```
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"
See also codec2/octave/nf_from_stdio.m and [Measuring SDR Noise Figure in Real Time](http://www.rowetel.com/?page_id=6172).
# Reading Further
1. [Open IP over VHF/UHF](http://www.rowetel.com/?p=7207) - Blog post introducing this project
1. [Open IP over VHF/UHF 2](http://www.rowetel.com/?p=7334) - Second blog post on uncoded OTA tests
1. [Previous Codec 2 PR discussing this project](https://github.com/drowe67/codec2/pull/125)
1. [Codec 2 FSK Modem](https://github.com/drowe67/codec2/blob/master/README_fsk.md)
1. [RpiTx](https://github.com/F5OEO/rpitx) - Radio transmitter software for Raspberry Pis
1. [rtlsdr driver](https://github.com/rtlsdrblog/rtl-sdr-blog) - Modified Osmocom drivers with enhancements for RTL-SDR Blog V3 units.
1. [rtlsdr driver](https://github.com/librtlsdr/librtlsdr) - Our rtlsdr driver is forked from this fine repo.
1. [Measuring SDR Noise Figure in Real Time](http://www.rowetel.com/?page_id=6172)

5
build_csdr.sh 100755
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@ -0,0 +1,5 @@
#!/bin/bash -x
# Automate building of csdr library, which is used by rtl_fsk application
PIRIP_DIR=$(pwd)
git clone https://github.com/ha7ilm/csdr.git
cd csdr && make

9
build_rtlsdr.sh
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@ -1,9 +1,10 @@
#!/bin/bash -x
# automate building of rtlsdr library and applications
# Automate building of rtlsdr library and applications
PIRIP_DIR=$(pwd)
git clone https://github.com/drowe67/rtl-sdr-blog.git
cd rtl-sdr-blog
git clone https://github.com/drowe67/librtlsdr.git
cd librtlsdr
git checkout development
mkdir -p build_rtlsdr
cd build_rtlsdr
cmake ../ -DINSTALL_UDEV_RULES=ON -DCODEC2_BUILD_DIR=${PIRIP_DIR}/codec2/build_linux
cmake ../ -DINSTALL_UDEV_RULES=ON -DCODEC2_BUILD_DIR=${PIRIP_DIR}/codec2/build_linux -DCSDR_BUILD_DIR=${PIRIP_DIR}/csdr
make rtl_sdr rtl_fsk