A bit of math, ts2iq, attention digital TV amateurs (and profis)

stream to IQ

either.

RELEASE SOURCE.

Symbolrate was 13372 kps.

while drying from the shower last night,

It's no coincidence that modern technology really kicked off about the time people started taking showers.

--

John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators

Any relation with the towel?

But hey Pantelje, whatever one thinks about your physicks views, you're quite together a frood when it's about writing code.

Regards, Mikko

The Skunkworks didn't need showers.

--

Reply in group, but if emailing remove the last word.

On a sunny day (Fri, 31 May 2013 09:42:13 -0700 (PDT)) it happened snipped-for-privacy@wmail.fi wrote in :

Well, hitchhikers guide, 42 IIRC, a simple answer...

Thanks,. Bit of background I am porting this to the Raspberry Pi, and there it outputs to the GPIO header (not to stdout). The Pi is not that fast, but fast enough.

Here is where the (more relevant to this group) hardware part starts.

I had a good look at these designs:

(scroll down for circuit diagram).

The serial link is not needed when using the Pi, I have build and tested several of those circuits, ordered a U270B, re-designed that hardware so it does no longer use those CMOS switches but a simple 74LS238 as demultiplexer, so less chips even. Also tried the differential approach I posted about here in the past.

Anyways there is a small HD camera coming out for the Raspberry Pi

The idea is now to have this: raspivid -t 999999 -o - | ts2iq_pi_version to make live DVB-S video. Either use the 470 MHz amateur band (depends on VCO, license), or build a 100 MHz exciter and mix up to GHz, (U2790 chip goes from 100MHz to 1GHz), Of course you can play your videos to via the DVB-S receiver without LNB connected...

When the U2790 chip has arrived and I get around to soldering things, I will publish diagrams, code, and test results of that super simple Pi digital TV setup.

The handshake (for the Pi to send the next byte) will be in the ts2iq_pi_version. I already wrote and tested all that, but now I am working with 2 different programs all the time on the Pi, ts2iq and send_iq ('serializer'). As now ts2iq is about completed, I can make a similar one program version for the Pi. On the Pi I can get up to get 3 Mbytes per second transfer makes for a maximum

12,000 kbps symbolrate, I am using a 6 MHz crystal for symbol rate clock (with a 4040 counter), and not the 24 MHz as in the French setup.

Any faster on the Pi and the FIFO gets empty on the Linux task switch. Adding the camera and ffmpeg (perhaps for encoding) I still hope to get at least

1500 symbolrate, FEC 7/8 may help too, but that still needs testing.

Try beat me to it:-) GPIO header | __________ camera |>[]-- raspivid -t 999999 -o - | ts2iq_pi_version -|- 2 x CY7C433_FIFO(8kB) -- 74LS238(2x1of4demux_)-- I-- LC nyquist filter -- |U2790B QAM|---< antenna | | || Q-- LC nyguist filter -- |__________|

-----|------------ Regards,

Physicks? it is just an industry using some brainwashed Einstein parrots to provide jobs for industry, building useless things (ITER) looking for Elvis alive (LIGO), looking for God particle (CERN), etc etc... and never going ANYWHERE.

Now look at electronics (oops I forgot the Quantum computah scam, advertising the analog computer, HA 'superposition', idiots), look at electronics and how far we have come, they almost re-invented Usenet...

On a sunny day (Fri, 31 May 2013 09:42:13 -0700 (PDT)) it happened snipped-for-privacy@wmail.fi wrote in :

GPIO header | __________ camera |>[]-- raspivid -t 999999 -o - | ts2iq_pi_version -|- 2 x CY7C433_FIFO(8kB) -- 74LS238(2x1of4demux_)-- I-- LC nyquist filter -- |U2790B QAM|---< antenna | | || Q-- LC nyguist filter -- |__________|

-----|------------

CY7C433_FIFO(8kB) -- 74LS238(2x1of4demux_)-- I-- LC nyquist

|| Q-- LC nyguist

-----|------------ |

handshake |

whatever

4040 divider | 6 MHz xtal

Oh, and the 'symbolrate handshake' is in fact just the FIFOs full signal that stops ts2iq_pi_version sending more data. The 2 FIFO chip FULL signals are combined with a NOR gate that I forgot to draw, so now the chip count is the same again :-)

I use short time memory for designing tronix and progromming, some time ago I found a box with LCD display I made long time ago, and I could not remember what it was (for).

Opening it and looking at the chips, all of the sudden: 'Oh now I remember'. Can't remember what it was now really....

Anyway, it is interesting working on these modulation systems, of course the ULTIMATE goal is to understand how advanced civilizations encode their data (extrapolation from what people do these days), and then processing some SETI noise to see if they have better TeeFee programs, or even Kermit. Miss piggy too.

Now THAT really is the ultimate crypto challenge, if they are anywhere at the same point or past us, their transmissions should look like random noise.. I am sure in a few years we have REALLY big shift registers (long periods before the randomness repeats), high levels of integration, so we should not be shy on looking for really long sequences.

For alien civilizations, let's say two hundred years to go from electricity to these sort of modulation systems. In the billion years that what we call universe is supposed to exist, the overlapping window of a few hundred years for sure reduces the probability of us being able to decode anything alien. On the other hand there are so many stars and most have planets, that increases chances. And then oh boy, their tv programs could be WORSE than ours.. and most will be too weak and even too old to receive. Maybe alien Miss piggy will look like humans...