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It’s unlikely that a shield as complicated as the Ethernet shield can be driven at the same time as the Video Experimenter. Most shields are not compatible with one another because of interrupts and timers. The VE requires use of timers and constant interruption with very precise timing to generate the video.
The overlay code is not designed for resolutions higher than the default. With such a slow microcontroller, there are only 6 instruction cycles to process each pixel. Higher resolutions just are not possible with the overlay. I can’t do the overlay any faster than it is. Higher resolution would require each pixel to be processed in 5 or 4 instruction cycles, and it just can’t.
You can’t use Serial output while generating video. Use the pollserial library that comes with the TVout library. If the microcontroller is being forced to handle serial communication interrupts, then it will interfere with the video.
You can go up to 192×128 or maybe higher with the Seeeduino Mega.
No, an external memory expansion would not help. You can’t access the memory fast enough. The video generation code is written in assembly, and it can’t be made any faster.
No, the simple Video Experimenter cannot do that. Not even close.
We are at nootropicdesign.com, of course.
We have a store: http://nootropicdesign.com/storeNo, it’s only for the Arduino Uno and Duemilanove. I’ve been very clear about what boards are supported, but everyone keeps trying to use it with different hardware!
Well, I really can’t teach people how to code if they have no experience. If you are able to compile the Defusable Clock firmware in Arduino and upload code, then I can tell you the few lines of code you may need to change.
Yes, that can be done. An LED pin can be repurposed, or one of the pins on the 6 pin header at the top of the board. Special coding is required but it is easy.
No bother at all. Yes, it would be great to use that fast processor for video. You would have to port the TVout code to PIC, though. The guts of the TVout code are written in AVR assembly, so it would be a significant undertaking, but should be possible. Look around and see if anyone has done composite video generation for that processor.
Yeah, that Due demo is impressive. I personally wouldn’t design a product for the Due, though, because there are so few out there. There are probably 100X as many customers that have Uno vs. Due.
Yes, that’s the Seeeduino Mega. I don’t buy off of eBay, though, because the boards are often counterfeit. You can buy directly from Seeed Studio:
http://www.seeedstudio.com/depot/Seeeduino-Mega-p-717.htmlThe shipping is pretty fast.
No, external interrupts are not enough. One of the microcontroller’s input capture pins needs to be connected. That’s not the same as an external interrupt. From my article about the problems with the Arduino Mega:
To perform video overlay, the Video Experimenter relies on an input capture pin (to capture the exact time that the pin has changed state). Even though the ATmega1280/ATmega2560 has 4 input capture pins, none of them are connected!
The Due will absolutely not work because it has 3.3V operating voltage.
The Uno R3 SMD edition is functionally the same as any other Uno.
