1. by Charles BrainG4GUO G4GUO@ARRL.NET 2012 BATC CONVENTION DATV-Express

2. 2 The main DATV-Express team members Ken Konechy - W6HHCPGM Manager Art Towslee- WA8RMCHardware Tom Gould- WB6PPCB Layout Charles Brain- G4GUOSoftware

3. 3 DATV-Express Goals of the Project Significantly reduce the price of Digital-ATV transmitters Provide an open platform for future DATV development Help educate the community and ourselves about new technologies. Get more DATV stations on-air Encourage more people to get licensed By product will be a Software Defined Transmitter for the 23 cms band with a B/W of up to 8 MHz.

4. 4 DATV-Express It all started when I bought a USRP2

5. 5 DATV-Express Overview of DATV-Express System System Block Diagram for DATV-Express DATV Transmitter

6. 6 DATV-Express Overview of Hardware Board USB2 Interface Cypress CY7C68013A FPGA Altera EP2C8T144CN DAC Analogue Devices AD9767ASTZ Clocks PLL/modulator for 1.3 GHz ADRF6750A Buffer amplifier GVA-84+ ~20 mW Optional symbol rate generator Si570 DC-DC power supplies allows single 12V input

7. 7 DATV-Express Overview of Hardware Board – cont’d Block Diagram for DATV-Express Hardware Board

8. 8 DATV-Express First prototype

9. 9 DATV-Express Overview of PC Software Operating System - Linux 32/64-bit then Win32 Loads FX2 firmware (Control Transfer) Loads FPGA firmware (EP1) Controls 1.3 GHz PLL (EP1) Controls symbol rate generator (EP1) I/Q offset calibration (EP1) Provides GUI

10. 10 DATV-Express Overview of PC Software – cont’d Take program/transport stream from capture device Converts to a transport stream with correct PIDS Adds SI Table information Adds FEC Does interleaving Keeps symbol rate constant, no overruns or under runs by adding Null transport packets Generates either IQ symbols or a bitstream Talks to exciter board via USB interface (EP2)

11. DATV-Express GUI Screen-shot (current)

12. 12 DATV-Express Overview of Hardware Board Software FX2 code (USB chip has 8051) C/ASM Programs FPGA Manages USB FIFO interface with FPGA I2C interface with 1.3 GHz PLL I2C interface with symbol rate generator I2C interface to FPGA General Housekeeping FPGA code, Verilog, Altera Quartus II Interpolates symbols to final sample rate Channel filter Writes to DAC

13. 13 DATV-Express DATV-Express Minimum System Specs DVB-S protocol QPSK modulation (will allow other modulations) Frequency Range:  950–1575 MHz (allowed by ADRF6750 chip) –1240–1300 MHz (allowed in USA) –1240–1325 MHz (allowed in Europe) Symbol-Rate: –Adjustable: 1 MSymb/sec -to- 5 MSymb/sec Forward Error Correction is selectable RF output ~ 20 mW buffered (SMA connector) Video Capture card allows for NTSC or PAL Initially designed for one video stream Operating system – first Linux-32/64 then Win32

14. 14 DATV-Express Current Project Status First prototype PCB built Linux GUI, DVB-S and DVB-T code working Basic FPGA code working Version 2 PCB being laid out

15. 15 DATV-Express Proof-of-Progress – 1st DVB-S Transmission

16. 16 DATV-Express DVB-S 1.2 GHz spectrum

17. 17 DATV-Express QPSK constellations ( with noise)

18. 18 DATV-Express DVB-S2 32APSK Constellation

19. 19 DATV-Express 6 MHz DVB-T spectrum with I/Q balance problem & filter passband ripple

20. 20 DATV-Express 1.3 GHz 7 MHz DVB-T on a PC with a Realtek USB Dongle and DVBDream

21. 21 DATV-Express What about DVB-T, DVB-S2, 8VSB etc? “Yes, they are possible....” “But, the team is only committed to DVB-S” We already have experimental support for Firewire/DV video input, text overlays, testcards, FFMPEG transcoding, 1080i HD and DVB-T.

22. 22 DATV-Express What about RaspberryPi ? “Yes, it should be possible....” Pi has hardware H.264 encoding / decoding and will have a 5 Megapixel camera soon. Has USB2 interface. No on board sound in. Code needed on Pi to convert raw H.264 data into a valid DVB transport stream and to load FPGA code on Express board. Can probably re-use some code already written. Need to wait for Pi foundation to write all the required hardware libraries to support camera. Express, will have to move FEC coding to FPGA so board supports transport stream. Only space for DVB-S

23. DATV-Express Hope to have final production PCB ready around Christmas time Intend to provide incremental software releases during the life of the board. Add DVB-S2 and maybe DVB-T2 Depends on demand but maybe a matching receiver optimized for < 2 Msymbols/s? Conclusion and Plans

24. DATV-Express Useful Links: My blog http://www.g4guo.blogspot.co.uk/http://www.g4guo.blogspot.co.uk/ Follow me on Twitter @G4GUO

25. DATV-Express Thank-you all!