Need Help with Prop Backpack and Overlay

marcwolf

Hi Folks.
Ok - I have finally got my Backpack to work as a Terminal using a Picaxe (Use the SerOut T9600)
Anyway it is working fine, I can display lines of text and its very clear using the prop_backpack_tv_terminal.binary.

If I load the prop_backpack_demo binary then I do get the overlay wothing however I have no text input.

But when I load the Overlay file (prop_backpack_overlay_terminal.binary) I am not seeing the overlay function. The feed from the camera is displaying correctly but the Backpack just does not display text.

This is the camera I am using http://www.sparkfun.com/datasheets/Sensors/Imaging/CM-26N.pdf and I have it set to NTSC mode (I'm in Australia). The Monitor I am using is displaying the image with no issues re H/V syncing.

I have tried for imedance issues using a resistor box. Both Jumpers are in the board

So it's down to HELP!!!!.

Tools I am using Prop Backback Loader 1.1 (with Clean 0.34). I have reloaded the Bootstrap sucessfully and the Prop accepts the loading of the Binaries iwth no issue.

Does anyone have any suggestions I could try, I REALLY need the overlay functionality

Many thanks
Dave

Minor Update, I have been experimenting with using Color. The colors are very washed out and to see them I need to put an 820ohm resistor in series with video output.

Phil Pilgrim (PhiPi)

The fact that the overlay demo works shows that the overlay system is working okay with your hardware. What text are you sending the terminal program? It's likely that you are not sending enough preconfiguration information to define the overlay windows prior to the text you want to appear in them.

-Phil

Duane Degn

I was having issues with my Propeller Backpack also. The text would kind of fade in and out.

It ended up being a bad solder joint on the 1/8" jack. I figure if it happened to me it's likely others have the same problem.

Another thing to consider, I think this is explained in the documentation, some of the small board cameras don't put out a the correct voltage amplitude. I think darker colors are supposed to work better in these cases (or was it lighter colors?).

I have a small board camera, and the overlay works well with it. It works better when I use my video camera as the video input.

Can you try a different video source?

I personally think the backpack is an amazing little piece of hardware.

Duane

marcwolf

Hi and thanks for the information.

Phil, here is what I am sending to the Backpack, I've excluded the Constants for brevity. This code works when the BackPack is in terminal mode but not when it is in overlay

[PHP]
low Propeller
pause 500
serout Propeller, T9600, (pCLS)
serout Propeller, T9600, (pHOME)
pause 500
main:
serout Propeller, T9600, (pCLS)
serout Propeller, T9600, (pHOME)
serout Propeller, T9600, ("Hello,", pUSECLR,15,"world",pUSECLR,0,"!")
serout Propeller, T9600, (pDEFWIN,1,5,5,6,7,pUSEWIN, 1, pCHGCLR,12)
serout Propeller, T9600, ("Text",pcr,"in",pcr,"Window",pcr,"1")
serout Propeller, T9600, (pUSEWIN,0, "I've Arrived")
serout Propeller, T9600, (pUSEWIN,1)
looper:
for b1 = 1 to 254
serout Propeller, T9600, (#b1,pcr)
next
pause 500
serout propeller, T9600, (pCLRW)
goto looper
End
[/PHP]

With Video sources - I am very limited as I am in Australia there is not a lot of NTSC sources available. It took me a while to track dowm PAL/NTSC video cams. I have tried both the cams (the application is sterio vision with the backpack only using the 'Right' channel as it were.)

Take Care
Dave

Phil Pilgrim (PhiPi)

You're using the tv_terminal protocol. The overlay software requires a different protocol. See the document here for details:

http://www.parallax.com/Portals/0/Downloads/docs/prod/prop/prop_backpack_tv_overlay.zip

-Phil

marcwolf

Hi Phil and thanks for the information.
I've read the Doco and found the Overlay Demo BS2 file. I'll translate this into PicAxe basic tonight.

Just so I understand, If I can get the Backpack to work with the PicAxe in Terminal mode then the open-drain issue has been fixed. This was one of the avenues that I was investigating re the Backpack not working in Overlay mode.

Also if the Backpack was running the Overlay demo then the Camera is providing the correct signal levels.

Many thanks for your help.
Dave

Phil Pilgrim (PhiPi)

If I can get the Backpack to work with the PicAxe in Terminal mode then the open-drain issue has been fixed.

Yes.

Also if the Backpack was running the Overlay demo then the Camera is providing the correct signal levels.

Yes, assuming the demo includes some opaque overlay data. If it's all transparent, then the camera could till be outputting too high a level to an open load, and the overlay would still work. By using transparent overlays only, the camera is always under load, since its signal is always at least partially passing through to the monitor's 75-ohm load. A camera with a correct 2V P-P output under no load will work with both transparent and opaque overlays.

-Phil