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Test Equipment Raspberry Pi Test Card Generator.

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Doz
 Doz
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Quick demo of a test pattern generator I've been working on... It's running on a poverty spec. early Raspberry pi, which can be found for little money these days.

The project should run on more powerful Pi's too... I'll share more when I've written it up.

It's currently got 10 "test cards" loaded , but you can load as many as you can fit on the memory card. You can navigate forward and back through the cards as required.

Video is displayed via composite on the workshop 4:3 LCD monitor. 

Yes it's doing the musak too ...

 
Posted : 07/02/2023 6:44 pm
PYE625, WayneD, peterscott and 3 people reacted
Hurty
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Hi Doz. That looks interesting! I think you may need to put your camera/phone on a stand. Any technical specification like horizontal resolution? bruch blanking/8 field sequence. Is the image a video capture or do you generate it from a file?. Test card music? There was a tape played in the late 70's that had the track "remember the days in the old school yard" which in my day was a breath of fresh air being a teenager at the time, don't hear this mentioned much when the subject of test card music comes up. Meanwhile I await your details of this project.

Adrian

 
Posted : 12/02/2023 11:05 am
RichardFromMarple
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Sounds interesting, I bought an early Pi a few years ago to use as a teletext generator but never got round to getting it up & running.

I downloaded a lot of library music years ago, & don't really get the chance to listen so.

 
Posted : 12/02/2023 4:39 pm
Doz
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Posted by: @hurty

Hi Doz. That looks interesting! I think you may need to put your camera/phone on a stand. Any technical specification like horizontal resolution? bruch blanking/8 field sequence. Is the image a video capture or do you generate it from a file?. Test card music? There was a tape played in the late 70's that had the track "remember the days in the old school yard" which in my day was a breath of fresh air being a teenager at the time, don't hear this mentioned much when the subject of test card music comes up. Meanwhile I await your details of this project.

Adrian

The resolution is a bit odd, I'll cover more in the final article. It works with BMP's, JPG's or PNG's. The music is a wav file that's looped. Once it's finished I'll make an .IMG file available, less the images and music, as I'm sure that'll land me in copyright hell. I've now added a switchable 1KHz tone to it as well. Sorry about the shaky footage. I've had a benign tremor since I was 14... 

 

 
Posted : 13/02/2023 11:47 am
WayneD
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Cool! I normally use a YouTube video streamed directly from a PS3 or recorded onto a VHS tape but this would be a lot less bulky.

 
Posted : 13/02/2023 5:57 pm
Doz
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A bit of an update. It's coming together, albeit rather slowly. I've created an .img file, which will be downloadable once I'm happy with it. I'll include a test image, and some copyright-free music (which subscribers to my YouTube channel may recognise), and a 1KHz tone, to avoid the copyright issues. I'm currently writing up the final bits on my website. I've made the memory card accessible on my enclosure, so I can swap the card out for (possibly) the teletext generator image. The output is currently split, so there's a video & audio output on the front panel, and it's also feeding a "PlayStation" UHF modulator, which I  find is of very good quality, although fixed to ch.36. It's switchable between I & G sound carriers for those in other PAL areas. I'll include details on altering the overscan settings, and switching to NTSC for those wishing to use that (you'll need a VHF modulator with the appropriate sound carrier for US use).

 

I 3D printed a front panel, but I'm not happy with it.. then my 3D printer broke down, so I've had to order a new hot-end and wiring loom for it, as it keeps throwing a thermal runaway alarm, and I've got a feeling it's not actually down to the hot-end but an intermittent break in the loom to the thermistor.... and I still need to get my 17TG100U lopt off to Mike Barker !  

 
Posted : 21/02/2023 3:45 pm
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RichardFromMarple
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I've used a PlayStation modulator for my analogue sets, which I can run from a USB socket.

I also made a similar setup using a very similar camcorder modulator with the same pinouts as the PlayStation one, but can be set to different UHF channels (30 to 40 I think).

 
Posted : 22/02/2023 10:17 pm
Doz
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It's completed, just doing the write up, and a bit of a video ...

I'm quite pleased with myself..

DSC 4060
 
Posted : 27/02/2023 11:52 am
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Doz
 Doz
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https://andydoz.blogspot.com/2023/02/pipatgen-raspberry-pi-television.html

 
Posted : 27/02/2023 12:00 pm
ntscuser, freya, Jayceebee and 1 people reacted
Doz
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Posted : 04/03/2023 9:01 pm
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hamid_1
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I downloaded the image file, wrote it to a 4GB SD card and tried it in a 1st generation Raspberry Pi. It worked straightaway. There were 3 sample pictures included; a test card with Raspberry logo, colour bars with VRAT logo and a picture containing some useful information about the system. There was also a 1KHz test tone on both audio channels but no music, presumably for copyright reasons. As you say, it's easy to add your own music or test card photos. The SD card can be inserted into a PC running Linux or even on the Raspberry Pi itself, then the files can be copied into the correct folders on the card.

RichardFromMarple if you are struggling to get your Raspberry Pi going, this would be an easy starter project.

I noticed you used the innards of a USB keyboard because you couldn't get the I/O pins to work. This was a bit unfortunate, but it's a creative solution. I'm afraid I can't help make it work as you originally intended, though at least you found another way. Sometimes that's part of the fun. There's often more than one way to solve a problem.

Actually I already have more than one way of generating test cards. The one I mostly use is a Lexar Digital photo viewer. Similar thing - it's a small box that takes a CompactFlash card and displays JPEG photos on TV as composite or S-video. There are buttons on top of the unit to switch between photos. Then there's the Mikey405 Test Card DVD. Finally I have a professional Philips PM5518TN test pattern generator with built-in modulator. It's multi-standard PAL/SECAM/NTSC and can also generate teletext and NICAM stereo sound. It's a fairly large, expensive machine that dates from the 1990s, I don't actually use it much, but it's always good to have multiple choices.

Just thought I'd mention another Raspberry Pi teletext project:

https://www.nathanmediaservices.co.uk/teletext-viewer/

This is a re-creation of the BBC CEEFAX service. As well as the web viewer, you can install software on the Raspberry Pi that generates teletext signals for use on a real vintage TV. Instructions are on the web page. When the Raspberry Pi is connected to the internet, the pages are refreshed with the latest news and information picked up automatically from the BBC, just like when Ceefax was still being broadcast. Offline, the last loaded pages will be shown. Have fun!

 
Posted : 05/03/2023 6:07 pm
ntscuser reacted
Doz
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@hamid_1 You should have music as well as a tone. Check your jack is fully inserted!

 

 
Posted : 05/03/2023 8:09 pm
hamid_1
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Success - the music is working!

Initially I used a pair of headphones with inline volume control to monitor the audio output, but I could only hear the 1KHz test tone in both ears, no music. With a different pair of headphones it worked correctly - 1KHz in one ear and music in the other. Plugging the original ones back in, I couldn't get any music even by wiggling the plug around in the socket. They must be wired wrongly. How strange.

Anyway, the problem is solved. Thankyou!

 
Posted : 08/03/2023 10:09 pm
Doz
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@hamid_1 how weird! I did think I'd got the image right. It was a bit of a pig to compress! Dreaded having to it again. Thanks for the comments. Nice that someone else has had a go at one of my projects!

 
Posted : 09/03/2023 1:11 pm
crustytv
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Now if you could build me a BBC Cow, with the ability to insert your own text below, I'd pay for all materials and your time & luv ya forever 😍 😉   Wanted one for years.

CrustyTV Television Shop: Take a virtual tour
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Crusty's 70s Lounge: Take a peek

 
Posted : 09/03/2023 9:13 pm
Cathovisor reacted
Cathovisor
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I wish I'd never let the COW we had in TC5 out of my sight now - and I was the one who sent it to Bradford 😭 

I even had a digital video recording of it on a hard drive recorder...

 
Posted : 09/03/2023 9:26 pm
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RichardFromMarple
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The COW is probably my favourite BBC1 logo, probably because it seemed a big advance on the mechanical mirrored globe that had been in use since 1969.

 
Posted : 09/03/2023 10:20 pm
Doz
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I've just had a look at what's required, and I think I can make a PiCow... leave it with me....

 

 
Posted : 11/03/2023 1:55 pm
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Doz
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Well, here it is, so far ... ladies, gentlemen and LGBTQ persons, may I present to you... the PiCOW 

 
Posted : 11/03/2023 6:37 pm
Lloyd, jcdaze and Jayceebee reacted
crustytv
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😍 😍

Words fail me, totally gobsmacked you've pulled that together in such a short period of time.  Mr Doz, I salute your ingenuity. 👍 

CrustyTV Television Shop: Take a virtual tour
Crusty's TV/VCR Collection: View my collection
Crustys Youtube Channel: My stuff
Crusty's 70s Lounge: Take a peek

 
Posted : 11/03/2023 6:44 pm
Doz reacted
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