The Portsdown 4 transceiver software has been specifically designed to be used with the Raspberry Pi 4 and the official Raspberry Pi 7 inch touchscreen. It will drive a Pluto SDR or the LimeSDR and the DATV Express board (DVB-S only).
Portsdown 4 is the simplest and easiest to construct, with a barebones system consisting of:
- Raspberry Pi4 2GB model
- 7" touch screen
- 8, 16 or 32 GB SD card
- Adalm Pluto or Lime SDRmini
This will give you a DVB-S2 and DVB-T DATV transmit system from 30 to 3500 MHz when using a Lime SDR and 50MHz to 4100 MHz with the Pluto.
With the addition of a MiniTiouner USB receiver [], you will have a full spec DVB-S/S2 DATV transceiver.
With the addition of the Knucker USB tuner you will also have DVB-T receive capabilities.
- 1 Capabilities
- 2 Hardware
- 3 Software
- 4 Langstone Microwave transceiver
- 5 Pluto Capabilities
- 6 FAQ
- 7 More information
The Portsdown 4 has the following transmit and receive capabilities:
- DVB-S, DVB-S2 and DVB-T (H264 only) transmissions from a Pluto SDR connected by USB
- DVB-S, DVB-S2 and DVB-T (MPEG-2 and H264) transmissions from a LimeSDR Mini or LimeSDR USB
- DVB-S (MPEG-2 and H264) transmissions from a DATV Express Board connected by USB
- Supported transmit video sources include the Raspberry Pi Camera, C920 WebCam or a USB-connected EasyCap composite video capture device
- Streaming to the BATC Streamer using the Raspberry Pi Camera or EasyCap composite video capture device as a source
- Display of streams from the BATC Streamer
When a MiniTiouner USB receiver is connected via USB:
- Reception and display of DVB-S and DVB-S2 (MPEG-2, H264 and H265) signals
When a BATC Knucker USB tuner connected by USB:
- Reception and display of DVB-T and DVB-T2 (MPEG-2, H264 and H265) signals
Portsdown test and alignment aids
- Control of a Pluto, LimeSDR Mini, DATV Express, ADF4351, Elcom and SLO Microwave Sources using the Portsdown 4 Signal Generator.
- Basic spectrum display of band occupancy using the "Portsdown Band Viewer" - requires a LimeSDR Mini to be connected.
No other models of Raspberry Pi or touchscreen are planned to be supported in the near future.
Portsdown 4 GPIO connections
Due to a reassignment of the GPIO pins on Raspberry Pi4, the connections are different to previous generations of Portsdown.
The Portsdown 4 GPIO Connections are defined here: Portsdown 4 GPIO Connections.
Powering the Pluto
The Raspberry Pi 4 has increased power capabilities on its USB ports, and the Pluto does not work well with USB Hubs, so it is recommended that you connect the Pluto directly to a USB3 port (the blue ones) on the Raspberry Pi 4. Do not use a USB hub or power the Pluto from its USB power port.
Full details of the Portsdown hardware are available here.
The Portsdown 4 software is available on a pre-programmed SD card from the BATC shop https://batc.org.uk/shop/portsdown-transmitter-pre-programmed-sd-card/
If you wish to build your own card the build is on GitHub at https://github.com/BritishAmateurTelevisionClub/portsdown4
You MUST start with a fresh build of Raspios Buster Lite (NOT the older Raspbian) on an SD Card of 8 GB or greater, so you will need to rebuild any previous Langstone or Portsdown A27 card.
Langstone Microwave transceiver
The Portsdown 4 software build is also compatible with the Langstone Microwave transceiver software, which can be loaded from touchscreen selections (menu 2) AFTER the Portsdown software has been installed.
See https://wiki.microwavers.org.uk/Langstone_Project for more details and the full spec of the Langstone.
To operate, the Langstone software needs a Pluto to be connected by USB, and a compatible USB Audio dongle.
The Portsdown 4 support for the Pluto SDR is still undewr development and there are some limitations on functionality as described here Portsdown 4 Pluto.
- Is it possible to rotate the PiCam image in software as it is on it's side?
No - you need to do the camera mounting modification which Colin G4KLB described in CQ-TV 267
- Can I upgrade from Langstone or a previous version incluing Portsdown A27?
No - you must start with a clean image on your SD card
- When I try to update I get the error "Unable to contact GitHub for update, Internet connection to Google seems OK". The solution is to log in by ssh and run the following commands:
cd /home/pi wget https://raw.githubusercontent.com/BritishAmateurTelevisionClub/portsdown4/master/update.sh -O /home/pi/update.sh chmod +x /home/pi/update.sh ./update.sh
- I have built my Portsdown 4 but the screen is upside down. How can I get it the right way up?
Menu 3, System Config, Invert 7 inch
For more information see https://forum.batc.org.uk/viewtopic.php?f=103&t=6804