From 0a80b475c6547c4be04b1b5e06756faec5bdb3d2 Mon Sep 17 00:00:00 2001 From: David Honess Date: Sat, 26 Jan 2019 17:14:04 +0100 Subject: [PATCH] Update README.md --- README.md | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/README.md b/README.md index 6c86a0c..e1cdb36 100644 --- a/README.md +++ b/README.md @@ -4,9 +4,11 @@ ## What is Slow Scan TV? -SSTV is a picture transmission method to transmit and receive static pictures via radio. Similar to a fax machine, or a 90s dial up modem, SSTV is an analogue signal that resembles a high pitch cacophony of bleeps and screeches. It uses frequency modulation, where the signal frequency shifts up or down to designate pixel brightness and colour. A transmission consists of horizontal lines of pixels, scanned from left to right. +SSTV is a picture transmission method for transmitting and receiving static pictures via radio. Similar to a fax machine, or a 90s dial up modem, SSTV is an analogue signal that resembles a high pitch cacophony of bleeps and screeches. It uses frequency modulation, where the signal frequency shifts up or down to designate pixel brightness and colour. A transmission consists of horizontal lines of pixels, scanned from left to right. -The International Space Station has a long history of transmitting SSTV signals and these instructions show you how to receive them using just a Raspberry Pi computer and an RTL-SDR USB dongle. +The International Space Station has a long [history](https://www.spaceflightsoftware.com/ARISS_SSTV/archive.php) of transmitting SSTV signals and these instructions show you how to receive them using just a Raspberry Pi computer and an RTL-SDR USB dongle. + +Why use a Raspberry Pi? This could be done using a desktop PC or Mac however you often need to leave the receiver running overnight, waiting for the ISS to fly over your location, and it's usually easier to tie up a Raspberry Pi with this task than your main utilitarian computer that you use all the time. ![image](https://www.spaceflightsoftware.com/ARISS_SSTV/uploads/28614.jpg) @@ -17,13 +19,21 @@ To have a quick play, it is possible to install a mobile phone app that decodes - Android: [Robot36](https://play.google.com/store/apps/details?id=xdsopl.robot36) - Apple IOS: [CQ SSTV](https://itunes.apple.com/us/app/sstv-slow-scan-tv/id387910013) -Here's an MP3 test file you can [download]() and play. +Here's an MP3 test file you can [download](https://raw.githubusercontent.com/davidhoness/sstv_decoder/master/sstv_test.mp3) and play. + +## What you will need + +- Raspberry Pi 2B or later, USB keyboard, mouse and monitor +- RTL-SDR USB dongle (search for `RTL2832U`, get one that comes with an antenna) ## Initial setup and test +1. A guide for setting up your Raspberry Pi can be found [here](https://projects.raspberrypi.org/en/projects/raspberry-pi-setting-up). +1. We presume you are running Rasbian Stretch Desktop edition available [here](https://www.raspberrypi.org/downloads/) 1. Install prerequisites. - Start > Accessories > Terminal ``` + sudo apt-get update sudo apt-get install rtl-sdr sox pulseaudio qsstv ``` 1. Insert RTL-SDR dongle with antenna connected.