Is This Possible? CCTV To Stamp or Prop

NWCCTV

I have tons of CCTV cameras that I would like to do something with. Most of them are board sized cameras that I have pulled from their cases. Any how, I was wondering if there is a way to connect the signal wire to a Stamp or Prop and be able to use it for something along the lines of a line follower or any other useful purpose. I know there are other ways to do line following, I am just trying to find something useful to do with all the cameras I have. The entire outside of my house and inside my office are covered and I would rather not sell them if I can find a use for them.

Mike Green

With a bit of external hardware, you could get a Stamp to read the intensity of a black & white pixel at a single location on the camera image. This has been done throughout the history of microcomputers. You need a sync separator to regenerate the horizontal and vertical sync pulses, a down-counter to count off scan lines from the beginning of a picture frame, and a pixel counter that counts down from the start of the horizontal sync pulse using a crystal pixel clock and triggers a sample&hold to sample the signal at a pixel which can be run through a relatively slow ADC to give you the pixel intensity.

A Propeller could do much more of the work. You still need the sync separator and the sample&hold with the relatively slow ADC, even use the Propeller's built-in ADC if you want. A Prop cog counter could count down scan lines and could, with a carefully written assembly routine, trigger the sample&hold based on time from the horizontal sync pulse edge.

Both schemes would need some analog signal processing to clean up and buffer the signal for digitization. You may be able to find old schematics for I/O boards for the Apple II or an 8080/Z80 or the like.

NWCCTV

Thanks Mike. It sounds like more work than I wanted to put in to it. I have enough on my plate as it is so I guess I will use the old fashioned route. I can just sell the cameras on EBay and use the funds to get what I need, maybe even one of those cool new Laser Range Finders!!!!

Duane Degn

SteveWoodrough used Hanno's method of capturing a black and white image with a Prop to make a line following robot.

There are several ways to capture an image from a NTSC camera with a Prop. I've listed some of them in post #4 of my index.

NWCCTV

Thanks for the info Duane. What Steve did was pretty impressive. I am going to see if he has any schematics that I could follow.

Is there schematics anywhere on the forums of Phil's creation? I like the results shown in his pictures.

Duane Degn

NWCCTV wrote: »

Thanks for the info Duane. What Steve did was pretty impressive. I am going to see if he has any schematics that I could follow.

Is there schematics anywhere on the forums of Phil's creation? I like the results shown in his pictures.

I know Hanno has a schematic in the pdf he posted.

IIRC, Phil either describes the circuit in his forum post or it's described in the source code.

Here's picture of the hardware I used when using Hanno's method.



I actually checked yesterday to see if the ADC08100 chip used in Hanno's method would fit on the new Propeller Project board's surface mount area. It looked like it should work fine with the new Prop Project board. I don't know if the long(ish) traces from the surface mount area to the Propeller chip on the Project board would be a problem or not. (The above photo shows the chip used with a Propeller Protoboard (with relatively short traces between Prop and ADC08100 chip).)

While I checked to see if the chip would fit on the Prop Project board, I didn't solder the chip to the board since my one and only Propeller Project board is being used for a different (non-machine vision) type of project. With my Project board being tied up in a different project, I can't test it with the ADC08100 chip. If the ADC08100 chip works well on the surface mount area of the Project board, the Project board would be a great starting point for anyone interested in trying Hanno's method of video capture.

BTW, the ADC08100 chip cost me $10.28 back in March of 2011. The Digi-Key part # is ADC08100CIMTC-ND