Portsdown 2020 Buster Software

Introduction

The Portsdown Buster Software is a major change from previous Portsdown Software. The complete system needs retesting (and much of it needs re-writing) so only specific features will initially be declared as fit for use, with more features being added to the list as testing progresses.

The changes being introduced with this software include:

• A new LimeDVB mode that uses custom Firmware for a LimeSDR Mini to produce DVB-S and DVB-S2 signals.
• The ability to select whether LimeSDR calibration takes place before transmission
• A specific capability to transmit 1MS DVB-S2 with high reliability for use in repeater transmitters.

The notes below apply to the latest release 202002140, built on Portsdown Buster 2020-02-05.

Tested Modes of Operation using LimeDVB

To load the LimeDVB custom firmware, first check the current Firmware standard (Menu 3, Lime Config, Lime FW Info). It should be 1.30. If not, update it to 1.30 (Menu 3, Lime Config, Update to FW 1.30). Once at this standard, update with the DVB Firmware (Menu 3, Lime Config, Update to DVB FW).

If you do not have a touchscreen (for example setting up a repeater transmitter), you can achieve the same actions by using the Lime Config Menu on the Console (see Console mode Instructions) after connecting to the Raspberry Pi by ssh.

EasyCap input, H264 DVB-S2 output using LimeDVB

This mode transmits reasonable pictures at symbol rates from 125 kS to 3 MS.

Pi Camera input, H264 DVB-S2 output using LimeDVB

This mode transmits reasonable pictures at symbol rates from 125 kS to 3 MS, both with and without a USB Microphone dongle.

Animated Test Card (TCAnim) input, H264 DVB-S2 output using LimeDVB

This mode transmits reasonable pictures at symbol rates from 125 kS to 2 MS, both with and without a USB Microphone dongle.

Static Test Card input, H264 DVB-S2 output using LimeDVB

This mode transmits reasonable pictures from Test Card C (with callsign caption if selected), or the contest numbers card at symbol rates from 125 kS to 2000 MS. Audio is disabled when using the static test card or contest numbers.

C920 Webcam input, H264 DVB-S2 output using LimeDVB

This mode transmits good pictures and audio at symbol rates from 125 kS to 2 MS. Note that maximum definition from the C920 in this mode is currently 800x448. This is because of problems with the Linux driver for the camera.

Tested Modes of Operation using the Portsdown Filter-Modulator Board (DVB-S only)

EasyCap input, H264 output

This mode transmits reasonable pictures at symbol rates from 250 kS to 2 MS.

Pi Camera input, H264 output

This mode transmits reasonable pictures at symbol rates from 125 kS to 2 MS, both with and without a USB Microphone dongle.

Animated Test Card (TCAnim) input, H264 output

This mode transmits reasonable pictures at symbol rates from 125 kS to 2 MS, both with and without a USB Microphone dongle.

Static Test Card input, H264 output

This mode transmits reasonable pictures from Test Card C (with callsign caption if selected), or the contest numbers card at symbol rates from 125 kS to 1 MS. Audio is disabled when using the static test card or contest numbers.

C920 Webcam input, H264 output

This mode transmits good pictures and audio at symbol rates from 125 kS to 2 MS. Note that maximum definition from the C920 in this mode is currently 800x448. This is because of problems with the Linux driver for the camera.

EasyCap input, MPEG-2 output

This mode transmits reasonable pictures at symbol rates from 1 MS to 5 MS.

Pi Camera input, MPEG-2 output

This mode transmits reasonable pictures at symbol rates from 250 kS to 5 MS, both with and without a USB Microphone dongle.

Static Test Card input, MPEG-2 output

This mode transmits reasonable pictures from Test Card C (with callsign caption if selected), or the contest numbers card at symbol rates from 250 kS to 5 MS.

C920 Webcam input, MPEG-2 output

This mode transmits good pictures and audio at symbol rates from 250 kS to 5 MS.

Composite Video Output

The Composite video output works well both as a transmission mode (for driving analog transmitters) or as a second display. The output can be enabled when a 7 inch screen is in use from a button on the System Config menu reached from Menu 3.

Limitations

LimeSDR Models

Only the LimeSDR Mini (hardware versions 1.1, 1.2 and 1.3) is supported by this build. It is hoped to add LimeNET Micro support, but the LimeSDR USB will not be supported.

USB Webcams

The only USB Webcam that is planned to be supported in Portsdown Buster is the Logitech C920. If you have other webcams working with Portsdown Jessie or Portsdown Stretch, then please keep using the older software.

Carrier Mode using LimeDVB

When carrier mode is selected with LimeDVB as the selected output, and LimeDVB gateware loaded, the carrier is only transmitted at a very low level (-40 db?).

LimeRFE Control

Although there is a button to enable/disable a USB-connected LimeRFE, this does not yet do anything.

FreqShow

It has not been possible to make the FreqShow spectrum view work with this build.