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News Hedghog L Standards Converter

8 Posts
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FRANK.C
(@frank-c)
Posts: 252
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Topic starter
 

The FPGA's needed to build the previous Hedghog's have become very difficult if not impossible to get. The Hedghog L is in response to that.

The Hedghog L uses a iCE40HX1K FPGA and a PIC microcontroller. The FPGA is very small compared to the Cyclone FPGA's used in earlier Hedghog's. So much so that before I tried I did not know if even the most basic converter would fit in it. It was chosen mainly because at the time of starting this project there was a good number of them in stock.

As much as possible of the workings of the converter was farmed out to the PIC so as to leave as much room as possible free in the FPGA. Even after doing that the converter had to be pruned back hard in order to get it to fit.

It uses a 2 line interpolater as it was all that would fit.
It has an option of equalising pulses and also can do aspect ratio of 4:3 in to 4:3 or 5:4 out.
Doing 16:9 in to 4:3 or 5:4 out would need little more space but would not fit.
One way of obtaining more functionality is to use a multiple boot system to programme the FPGA. With a number of programme images stored in flash memory. Each image can have a totally different function to each other. Depending on which function is required the appropriate image can be loaded into the FPGA.

To this end I have used 4 programme images.
1 is a 405 line converter with 4:3 input 4:3/5:4 output.
2 is a 405 line converter with 16:9 input 4:3/5:4 output.
3 is a 405 line test card.
4 is a 819 line converter4:3 input 4:3 output.

It also has a programmable multi standard modulator

The PIC now does the programming of the modulators and the video decoder. It also provides the 4 MHz clock for the modulators, drives the LCD and reads the encoders.

It's performance isn't up to that of previous Hedghog's but that said it still does a reasonably good conversion.

Details can be found here

Frank

 

www.electronics.frankcuffe.ovh

 
Posted : 15/04/2023 4:11 pm
Lloyd reacted
Michael Dranfield
(@michael-dranfield)
Posts: 179
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Not available in kit form yet.? 

 
Posted : 15/04/2023 4:45 pm
FRANK.C
(@frank-c)
Posts: 252
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Hi Michael

 I don't supply Hedghog's or kits. You could contact forum member @freya. As he supplies Hedghog's

 

Frank

 

www.electronics.frankcuffe.ovh

 
Posted : 15/04/2023 4:59 pm
Lloyd
(@lloyd)
Posts: 1956
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Nice work squeezing it into a smaller chip! I might have to have a go at building one, I’m still using both my Hedghog 1’s that I built a while back, still working well!

Regards,

 Lloyd 

 
Posted : 15/04/2023 6:28 pm
FRANK.C
(@frank-c)
Posts: 252
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Hi Lloyd
Great to hear that your Hedghog 1's are still working well.
I think all you will need is on that web page. If there is anything you want to know just ask.

Frank

www.electronics.frankcuffe.ovh

 
Posted : 15/04/2023 7:16 pm
Lloyd reacted
Doz
 Doz
(@doz)
Posts: 1535
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Ah yes the "L" model - no clock, no rev-counter 😀 

 
Posted : 17/04/2023 12:00 pm
helloekco reacted
FRANK.C
(@frank-c)
Posts: 252
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🤣 🤣 🤣 

I hadn't thought of it in that way, but how apt.

I designated it "L" to mark the move to Lattice FPGA.

Frank

www.electronics.frankcuffe.ovh

 
Posted : 17/04/2023 12:34 pm
Doz reacted
slidertogrid
(@slidertogrid)
Posts: 1114
Prominent Member Registered
 

 I contacted Stephen for a ready built converter. It arrived today and I am very pleased with it. Easy to use, comprehensive instructions are supplied. I connected it to my faithful Dynatron and it works very well!
I have taken a couple of pictures. This is a slightly early birthday present to myself it will be my bench converter and means I won't have to keep unplugging the other Hedghog each time I want 405 on the bench.
Thanks Frank - thanks Stephen ! Much appreciated!
Rich.

20230425 122009
20230425 121931
20230425 123443

 

 
Posted : 25/04/2023 5:16 pm
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