A little HELP!!

[aerostar]

From the depths of the old files I found this -




On the STV PDF, it shows Circuitry around pins 5 and 6 I incorporated this, but I see the schematic above does not, I think as long as you have a good smoothed 5 volt power supply with good decoupling caps, there should not be a problem. However he does not show decoupling caps on his 9-12V DC circuit, 100N/220N should be in parallel with his 47uF caps and be close to the regulator.

On my board R3 (3k3) not fitted, My board, and the program you have uses CSYNC to work out the switching of modes, from what I remember I found odd problems using the MUTE, but cannot remember exactly what ! I think it did not always change the level when it should have or took a while to change.

Different coloured characters, It is in
DISPLAYCHAR:

WDATA = %0001011100000000 + STVCHAR

Bits 10,9, and 8 internal ram buffer, page 7 of my PDF, according to the STV data control the colour of the character.

You will have to try that when you get your system running correctly

[Ramius]

Again my greatest thanks! I just received three new STV5730A's so I will build the boards with the same component values you are using. Again, Thank you!

[aerostar]

Out of interest what supplier are you using to get the chips and what price ?

The schematic is not mine - it was used as a guide, however the values of resistors etc are the same, and what is used in the STV pdf.

[Ramius]

Hi Aerostar!
Just wanted to update everyone on the progress! The schematic was a big help! I had used a different schematic and had character timing problems. One line would be shifted left and the next line was 1 pixel right! Now the text is perfect thanks to you! Again I appreciate everything you have done. You are the best!

Sincerely, Ed

[Ramius]

Hi Aerostar!
For some reason, probably needing new glasses, I miss your question about where to buy and cost! Here is the link: https://www.utsource.net/search.aspx...chWay=1&page=1

Best, Ed

[Ramius]

Hi!
Not sure if anyone is still watching this thread and I would love to ask a few more questions if it would be okay?

Thanks, Ed

[MikeGTN]

Hi Ed,

Seems like you are making some progress on this project. I was tempted to purchase some chips from the supplier, but now think will wait a while longer to see how your results conclude. I was a little concerned given how long these devices have been EOL about them being actually genuine. So will be an interesting story to hear how you finally progress & about any discoveries you make along the way.

Certainly aerostar has proven the code for usage on the NTSC video standard with real life testing of his original prototype boards.

Mike.

[aerostar]

The chips as far as I know were never cloned, so I would say UTsource are genuine. It is a specialised IC and were used by cctv companies and video equipment manufacturers. In the UK they are still being used in the Amateur radio fraternity. It is a long time since EOL, but they are still very useful.

If you go here http://dunstabledownsradioclub.org and choose TV Streams, GB3TZ in beacon mode (when not being used) the display is done using the STV chip, controlled by a Pic micro - (done in assembler, not by me) , the Pic also controls the repeater logic.

My involvement in these chips - way back in 2003ish was to insert time overlay in cctv systems which did not have their own OSD, and using MSF or GPS to provide accurate time.

[Ramius]

Hi All!
When I purchased the chips the fact that they were offering large quantities at a discount suggested they were still being manufactured. Okay back to the code stuff. In the beginning of the code there are "con" statements and yet there does not seem to be any reference to these statements. Why are these statements part of the code? "NTSC." appears on the screen with or without a video reference. I wish to get to the point where I can place text such as STBRPM (Starboard RPM) and PORTRPM (Port RPM with a variable of 4 digits following the text while there is a video input signal from a camera. How can this be done? Maybe I could start with something simple such as moving the "NTSC." from the right side of the screen to the left? Again my greatest thanks!

Ed

[aerostar]

Some "Con" statements left over from debug etc code that was stripped out as I said somewhere earlier, and were also used as memory jogger.

NTSC. will appear as this program always sends on screen refresh regardless of whether there is video input or not, it is down to you what you wish to be displayed with or without incoming video, it was for video repeater ident.


This is the part you need to understand about placing text on screen

HEADER:
LINECOUNTER=2 'SET START POSITION ********* line 3 from top (0-2 = 3!)
CHARCOUNTER=23 'SET CURSOR POSITION***********Character position start 23rd from left
GOSUB SETLINE
FOR CHARS2=0 TO 4
READ CHARS2, ASCCHAR
gosub GETSTVCHAR 'CONVERT ASCII TO STV
GOSUB DISPLAYCHAR
NEXT
RETURN

NOVIDEO:
LINECOUNTER=5 'SET START POSITION
CHARCOUNTER=4 'SET CURSOR POSITION
GOSUB SETLINE
FOR CHARS2=6 TO 23 ' FROM EEPROM DATA
READ CHARS2, ASCCHAR
gosub GETSTVCHAR 'CONVERT ASCII TO STV
GOSUB DISPLAYCHAR
NEXT
RETURN

with regards to getting your RPMs on screen the DIG command would probably help,

so if you had a reading of 2400 as rpm in a word byte RPM, I THINK (following is UNTESTED)

ASCCHAR = RPM DIG 1
This gives a value of 2, and as it happens the character matrix in the chip will display 2 as if you look at the table the numbers come first

then
GOSUB DISPLAYCHAR

then

ASCCHAR = RPM DIG 2
This gives a value of 4

and so on to dig 4, you could make a loop to do this.

Not quite sure what happens if the value is below 1000, but you could easily check that prior to doing DIG 4 and put a blank there instead, skipping the DIG 4.