Software capabilities and issues

The latest Software for the Portsdown Transmitter is version 201807040 (the version is the issue date with an added 0-9 serial).

There are now 2 versions of Portsdown software:

1. Portsdown 2018 Stretch, which should be used for all new builds, and supports both the Raspberry Pi 3 B and the Pi 3 B+ https://github.com/BritishAmateurTelevisionClub/portsdown
2. Portsdown 2018 Jessie, which is the software that has been developed since the beginning of the project and will be maintained with similar capabilities to the "Stretch" build for as long as possible. This can be found at https://github.com/BritishAmateurTelevisionClub/rpidatv.

This software supports the following:

Supported hardware

• Raspberry Pi 3 Model B, with or without a 3.5 inch diagonal Waveshare touchscreen.
• Raspberry Pi 3 Model B+, (Portsdown 2018 Stretch software ONLY)
• Alternatively, the TX can be controlled over the network from another computer.
• The use of a keyboard and monitor connected directly to the Pi is not supported.
• The Pi will control an ADF4351 Synthesizer with a 10 or 25 MHz or other Reference Oscillator.
• Video input from an EasyCap type USB capture device, Pi Camera or selected webcams.
• Support for the C170, C270, C525, C910 and C920 Webcams is provided on a best-efforts basis

Outputs

Currently the Portsdown s/w will output:

• Dirty (ugly) QPSK signal on 437 MHz for testing,
• I and Q signals to the Portsdown Filter/modulator board,
• Control for a DATV Express in DVB-S mode.
• H264 coded video to a DTX-1 through a TS Dock board
• Stream to RTMP server such as batc.tv

Modes

• In IQ output mode, the Pi will encode the Pi Camera, the EasyCap or the on-board test card at up to 4 MS/s.

• In DATV Express mode, it will transmit MPEG-2 or H264 picures from the RPi Camera at 125 KS/s - 4 MS/s

• In "ugly mode" it will encode from these sources reliably at 125KS/s and sometimes at 333KS/s.

• In streaming mode, it will send Pi Camera or EasyCap pictures and sound to the BATC Streamer, or to any other compatible streamer.

• With an added RTL-SDR, the included LeanDVB monitor receiver will display strong DVB-S H264 signals of up to 1000 KS/s.

• The ADF4351 VCO or a DATV Express can be controlled as a Signal Generator with the option of QPSK modulation

• The FreqShow Spectrum Viewer can be selected from Menu 2 of the touchscreen.

Future Enhancements

There is a very long list of things to get working properly. Here are the highlights:

• Display transmitted image on the LCD in all modes
• Add sound channel to H264 video modes

Version history

• Version 201612310 Introduced a blank background behind the receive display, which in now part of the core capability.
• Version 201701020 introduced automatic selection of EasyCap input and TV standard.
• Version 201701080 introduced installation of Waveshare Touchscreen drivers during install, disabled the screensaver and added a screen logo at next boot.
• Version 201701190 Added stability improvements allowing 4MS SR, increasing reliability and reducing lock-ups. It also adjusted the touchscreen display to be centered in the screen
• Version 201701230 Added an Advanced Setup Menu. The fallback IP address was disabled, and the update script made more resilient to internet connection problems.
• Version 201701270 Added the ability to set the reference frequency and power for the ADF4351. It also corrected the selection of Carrier and Carrier Null modes, improved band switching and added menu items for future enhancements.
• Version 201701280 Bug fix for new ADF4351 functionality introduced in 201701270
• Version 201702020 New version of pi-sdn for button-initiated shutdown without error messages. Install and update improvements to allow easier testing and subsequent fielding of development versions.
• Version 201702060 Introduced basic support for the DATV Express modulator board
• Version 201702090 Introduced support for updated DATV express_server software. PTT capability and full SR range.
• Version 201702100 Completed the DATV Express capability, including Port switching, and tidied the switching between touchscreen and console.
• Version 201702110 Bugfix for DATV Express
• Version 201702190 Enabled streaming modes, lip-sync for MPEG-2 and switchable viewfinder.
• Version 201703060 Added the capability to adjust the frequency and SR for the touch screen presets.
• Version 201704030 Enabled IPTSIN mode and the transmission of contest numbers without a camera.
• Version 201704050 Update package lists before upgrade (bugfix for 201704030)
• Version 201704080 German Menus. Waveshare B display support and TonTec selection bug fix
• Version 201704160 Revised boot-up procedure, Display IP Address on splash screen. Update new build Jessie baseline.
• Version 201705200 Enabled the Pi Cam auto-shutter and improved the Shutdown button functionality.
• Version 201705301 Added a second Touchscreen menu with a shutdown button and enabled Contest mode operation from the touchscreen
• Version 201706301 Adds a number of menu options and the ability to run beta software using a recompiled version of ffmpeg.
• Version 201707120 Adds a PAL composite video output mode from the RPi and corrected the test card sizes.
• Version 201707222 Adds the ability to transmit MPEG-2 and stream from an EasyCap. Video and sound switching is provided.
• Version 201707311 Adds an Info screen on Menu 3, and sound pass-through in "Vid Out" mode.
• Version 201708150 Adds dedicated repeater streaming modes and video still capture.
• Version 201710081 Adds RTL-SDR functionality and keyed transmit.
• Version 201710280 Adds the basic Signal Generator functionality
• Version 201711031 Adds touchscreen calibration
• Version 201711271 Adds an HD Pi Camera MPEG-2 mode and a static MPEG-2 test card.
• Version 201712181 Included a total re-write of the touchscreen touch response function and added 480p MPEG-2 modes
• Version 201801012 Adds the FreqShow Spectrum viewer and basic support for the Element 14 7 inch screen.
• Version 201801061 Adds the ability to use DATV Express or switchable attenuators with the SigGen and tidies RX switching
• Version 201802041 Includes a major menu rewrite and add the facility to use the attenuator and transverters.
• Version 201802202 Minor bugfixes including C920 WebCam functionality
• Version 201803061 H264 HD streaming from C920. Additional HD, widescreen and test card modes
• Version 201803181 Revised C525 webcam reset logic. Corrected audio switching bug. Added C910 Webcam Support
• Version 201804020 Added functionality (including software update) from the touchscreen.
• Version 201804061 Adds FreqShow and VideoView functionality and other minor improvements for the Element 14 7 inch Screen
• Version 201804251 Adds an RTL-FM Receiver on Menu 2 and improves visibility of the DATV Express Firmware load
• Version 201805150 Adds a locator bearing calculator and improves the Composite video output facility.
• Version 201807041 Adds an independent LeanDVB Receiver Menu, and a Receive LO Generation Capability.

Last updated 6 July 2018. DGC