Merge pull request #88 from Guenael/guenael

chore(readme): not decoding issue fixed & documented

Makefile

@@ -25,4 +25,4 @@ clean:
 	rm -f *.o wsprd/*.o $(TARGETS) fftw_wisdom.dat hashtable.txt selftest.iq
 
 install:
-	install rtlsdr_wsprd /usr/local/lib/rtlsdr_wsprd
+	install rtlsdr_wsprd /usr/local/bin/rtlsdr_wsprd

README.md

@@ -2,7 +2,7 @@
 
 ![rtlsdr-wsprd](art/rtlsdr-wsprd-web.jpg)
 
-![Project Status](https://img.shields.io/badge/status-broken-red)
+![Project Status](https://img.shields.io/badge/status-OK-green)
 ![Workflow Status](https://img.shields.io/github/workflow/status/Guenael/rtlsdr-wsprd/CI)
 ![Last commit](https://img.shields.io/github/last-commit/Guenael/rtlsdr-wsprd)
 ![Commit activity](https://img.shields.io/github/commit-activity/m/Guenael/rtlsdr-wsprd)
@@ -12,14 +12,29 @@
 ## TL;DR
 
 This project aim at decoding WSPR signals using an RTL device, usually connected to a Raspberry Pi.
-To install and use your dongle on a Raspberry Pi with a *Rasbian OS* with a *4.x* Linux kernel:
+To install and use your dongle on a Raspberry Pi with a Raspberry Pi OS, follow these steps:
 
 ```bash
-sudo apt-get update && sudo apt-get -y install build-essential clang cmake libfftw3-dev libusb-1.0-0-dev librtlsdr-dev libcurl4-gnutls-dev ntp git
+echo "== Install dependencies"
+sudo apt-get update && sudo apt-get -y install build-essential clang cmake libfftw3-dev libusb-1.0-0-dev libcurl4-gnutls-dev ntp git
+
+echo "== Install rtl-sdr library (on RPi, don't use your distro package)"
+git clone https://github.com/osmocom/rtl-sdr
+cd rtl-sdr
+mkdir -p make
+cd make
+cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr -DDETACH_KERNEL_DRIVER=ON -Wno-dev ..
+make
+sudo make install
+cd ../..
+
+echo "== Install rtlsdr-wsprd"
 git clone https://github.com/Guenael/rtlsdr-wsprd
 cd rtlsdr-wsprd
 make
 make install
+
+echo "== Start/test rtlsdr-wsprd"
 rtlsdr_wsprd -f 2m -c A1XYZ -l AB12cd -g 29
 ```
 
@@ -40,32 +55,47 @@ This application written in C does:
 
   1. Install a Linux compatible distro on your device.
 
-     With **RasberryPi** devices, use a kernel **4.x ONLY**. There is a know bug related to later version 5.x.
+     For Raspberry Pi, you can download official images here: https://www.raspberrypi.com/software/operating-systems/
 
-     You can use this image : https://downloads.raspberrypi.org/raspbian_lite/images/raspbian_lite-2019-04-09/
+  1. It's a good practice to update your OS. On a RaspberryPi, run this command usual:
+  ```bash
+  sudo apt-get update && sudo apt-get upgrade
+  ```
 
-     Update your OS as usual:
-     ```bash
-     sudo apt-get update && sudo apt-get upgrade
-     ```
   1. Install dependencies & useful tools (for example, NTP for time synchronization). Example with a Debian based like Raspbian:
-     ```bash
-     sudo apt-get update && sudo apt-get -y install build-essential clang cmake libfftw3-dev libusb-1.0-0-dev librtlsdr-dev libcurl4-gnutls-dev ntp git
-     ```
+  ```bash
+  sudo apt-get update && sudo apt-get -y install build-essential clang cmake libfftw3-dev libusb-1.0-0-dev libcurl4-gnutls-dev ntp git
+  ```
+
+  1. Install `rtl-sdr` library manually. **Do not use the librtlsdr-dev package on RaspberryPi** There is a know bug with this lib and rtlsdr_wsprd will not be able to get enough samples (don't decode anything & 100% CPU pattern).
+  ```bash
+  git clone https://github.com/osmocom/rtl-sdr
+  cd rtl-sdr
+  mkdir -p make
+  cd make
+  cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr -DDETACH_KERNEL_DRIVER=ON -Wno-dev ..
+  make
+  sudo make install
+  cd ../..
+  ```
+  Note: You may have to re-plug you dongle if it was already connected, or play with `udev` if it is not automatically recognized.
+
   1. Clone this repository:
-     ```bash
-     git clone https://github.com/Guenael/rtlsdr-wsprd
-     ```
+  ```bash
+  git clone https://github.com/Guenael/rtlsdr-wsprd
+  ```
+
   1. Build the application:
-     ```bash
-     cd rtlsdr-wsprd
-     make
-     make install
-     ```
-  1. Start the application with your right parameters, ex. for the 2m band, with a fake callsign (A1XYZ):
-     ```bash
-     rtlsdr_wsprd -f 2m -c A1XYZ -l AB12cd -g 29
-     ```
+  ```bash
+  cd rtlsdr-wsprd
+  make
+  sudo make install
+  ```
+
+  1. Finally, start the application with the right parameters/options for you (frequency, callsign, locator etc... Fake example below):
+  ```bash
+  rtlsdr_wsprd -f 2m -c A1XYZ -l AB12cd -g 29
+  ```
 
 ## Tips (for your Raspberry Pi and SDR dongles)
 
@@ -82,13 +112,8 @@ This application written in C does:
 
 Most of RTL dongles use a cheap crystal, and frequency drift can effect the decoding & performance. The use of no-name RTL dongle for VHF/UHF bands usually require crystal modification, for a better one. External clock could be also used, like GPSDO or rubidium reference clock, aligned on 28.8MHz.
 
-Some manufacturers intergrate a 0.5ppm TCXO. It's the best second option, after an external clock. Based on my personal experience:
+Some manufacturers integrate a 0.5ppm TCXO. It's the best second option, after an external clock. Based on my personal experience:
 
 - NooElec NESDR SMART : Works fine out of the box
 - RTL-SDR Blog 1PPM TCXO : Works with some drift, require additional mass, or a better enclosure
-- Other no-name like : RT820, E4000, FC0012, FC0013, can work, but require modification and drift a lot
-
-## OS & Linux kernel requirement for RaspberryPi devices
-
-I have no idea why this app works fine for RPi with a kernel 4.x and not 5.x. Using a x86_64, rtlsdr-wsprd works perfectly fine with both versions of the kernel. This is probably related to an issue with pthread, and I have to investinage this point.
-If you have some knowledge about this, your help is welcome!!
+- Other no-name like : RT820, E4000, FC0012, FC0013, can work, but require modification and usually drift a lot