BATC Video Source Construction Details

Ideas, technical topics, help and discussion for ATV enthusiasts
Forum rules
This forum is run by the BATC (British Amateur Television Club), it is service made freely available to all interested parties, please do not abuse this privilege.

Thank you
G8GKQ
Site Admin
Posts: 2074
Joined: Sun Mar 22, 2009 1:21 pm

Re: BATC Video Source Construction Details

Post by G8GKQ » Thu Jan 21, 2021 10:29 pm

Hi Alec

Those 3 files should be created at startup, straight after the Raspberry Pi boots.

The first thing that I would look at is your power supply and the connecting lead. If they were marginal, there could be a corruption during the creation of those files (which, for a short time, uses a lot of processing power). The extra processing load would increase the current drain and perhaps cause a problem as those files are written to the card.

Aim for 5.20 volts measured at the Raspberry Pi and monitor with an oscilloscope during startup to see if it dips.

Dave, G8GKQ

g8lce
Posts: 201
Joined: Sun Dec 06, 2015 10:26 am

Re: BATC Video Source Construction Details

Post by g8lce » Fri Feb 12, 2021 5:14 pm

Dave this is a good idea to 'recycle' an old RPi. One thing that could be useful would be a LED to say it is on and running. Then when switching it off you could wait for the LED to go out. Resistor and LED on a GPIO and some software?

Martin G8LCE

radiogareth
Posts: 671
Joined: Wed Jan 06, 2016 9:46 am

Re: BATC Video Source Construction Details

Post by radiogareth » Fri Feb 12, 2021 7:28 pm

Martin, as the Vidscource card builder I wondered about this and a bit of google led me to this solution.
https://howchoo.com/g/ytzjyzy4m2e/build ... -indicator
However, I never bothered as I just use a clear case and watch the Activity LED when I shut it down. (Pi zero in my case).
Hope that helps.
Gareth G4XAT

aerostar
Posts: 23
Joined: Tue Jul 26, 2016 7:40 pm

Re: BATC Video Source Construction Details

Post by aerostar » Sat Feb 13, 2021 9:14 am


g8lce
Posts: 201
Joined: Sun Dec 06, 2015 10:26 am

Re: BATC Video Source Construction Details

Post by g8lce » Sat Feb 13, 2021 10:46 am

This looks like a good answer. It just gives that little bit more information about your video source to show it is working and don't turn off the power yet!
And no extra software.

Pity that pin is in use on the Ryde as that would have helped in my Ryde watchdog project. That looks at the i2c connection. The Rydes have not crashed lately though but I still want to be able to switch the Rydes off safely etc. anyway....

Thanks

Martin G8LCE

m1cdq
Posts: 89
Joined: Thu Feb 28, 2019 4:28 pm

Re: BATC Video Source Construction Details

Post by m1cdq » Thu Mar 04, 2021 1:28 pm

how can i increase the off delay from 2 seconds to about 7 seconds.
the reason is i plan to add an intervalometer to pins 18/20 to rotate the test cards
but it keeps triggering the shut down due to shutter delay
71iCzByuFPL._AC_UY218_[1].jpg
71iCzByuFPL._AC_UY218_[1].jpg (4.56 KiB) Viewed 539 times
i can set it to trigger a test card change at set timing by using the interval timer. or manually override just by pressing the button

Im assuming i need to edit camtc23a.sh
but not sure which bit

G8GKQ
Site Admin
Posts: 2074
Joined: Sun Mar 22, 2009 1:21 pm

Re: BATC Video Source Construction Details

Post by G8GKQ » Thu Mar 04, 2021 2:02 pm

Roger

You need to increase the count in lines 65 and 147 https://github.com/BritishAmateurTelevi ... 23a.sh#L65 and https://github.com/BritishAmateurTelevi ... 23a.sh#L65 from 19 to 69. They are counting the number of times that 'sleep 0.1 seconds' has happened.

Dave

m1cdq
Posts: 89
Joined: Thu Feb 28, 2019 4:28 pm

Re: BATC Video Source Construction Details

Post by m1cdq » Thu Mar 04, 2021 11:04 pm

thank you for that.
i now have an intervalometer connected to pins 18/20
I am now able to change cards at a push of a button or set the interval timer to change automatically at what ever set period i like

m1cdq
Posts: 89
Joined: Thu Feb 28, 2019 4:28 pm

Re: BATC Video Source Construction Details

Post by m1cdq » Fri Mar 05, 2021 1:49 am

having a little play around and reading the instructions

Code: Select all

Inserting New Images
Additional image files without a banner should be 720x576 .jpg files, and those for use with a banner should be 640x480. Each image needs to be accompanied by a text file named in sequence like tcdata10.txt and containing:

tcprog
testcard640
40
52
CQ
G8GKQ in IO91CC
The number in the filename determines the sequence that the card is displayed in; for example the card specified in tcdata10.txt will be displayed in the 10th button push after the first card.

The first line must be tcprog.
The second line is the filename of the .jpg image to be displayed, without the .jpg extension.
The third line is the x displacement of the bottom left of the card.  This should be 40 for cards with a banner and 0 for cards filling the screen.
The fourth line is the y displacement of the bottom left of the card.  This should be 52 for cards with a banner and 0 for cards filling the screen.
The fifth line is the text for the "bubbles".  A maximum of 5 characters.  Some special characters such as "-/P-" can be displayed (try it).
The sixth line is the text for the scrolling banner.
I have found out if you leave the 5th line blank you will have the banner but not the floating balls

Code: Select all

tcprog
testcard640
40
52

G8GKQ in IO91CC

Post Reply

Return to “General ATV Discussion”