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Topic: Arduino Ethernet and TVOut? (Read 1 time) previous topic - next topic

uberhund

May 14, 2012, 03:59 pm Last Edit: May 14, 2012, 04:04 pm by uberhund Reason: 1
I've successfully implemented the DemoNTSC sketch using later versions of the TVOut libraries on an Arduino Uno.

However, the same sketch and circuitry does not display video when uploaded to an Arduino Ethernet board, regardless which version of the TVOut library I use. I can detect some sort of signal from the Arduino Ethernet, but the analog TV I'm using is not able to render it into video.

Does anyone know what changes might be required to implement any version of TVOut libraries to work with an Arduino Ethernet board?
Santanyana was only half right. We are doomed to repeat history with impunity, whether we choose to remember it or not

RandallR

I don't know if this is the problem because I have not looked at the Ethernet libraries.  But the TVOut libraries take over Timer1 and possibly Timer 2.  This can play hell with PWM, Tone and other things.  It may be that your Ethernet is one of those things.

uberhund

Thanks for the observation, RandallR. I've been looking at conflicts and notice potential others as well (e.g., pin 11 on the Arduino Ethernet card may be in use by both the ethernet and TVOut libraries).

I've been trying to avoid it, but it looks like I will have to implement ethernet on a separate Arduino from the TV driver, and communicate between the two using I2C, which doubles the cost and complexity of the project.

Either that, or wait a year to get my hands on a Raspberry Pi.
Santanyana was only half right. We are doomed to repeat history with impunity, whether we choose to remember it or not

RandallR

If you can program, you might want to look at the libraries and see if you can resolve the conflict.  For example, TVOut uses Timer 2 for audio generation.  If that is the conflict and you don't need audio, then disable that part of the TVOut library.  You can download the Datasheet for the processor from ATMEL.  This gives a very good description of the various timers. 
I was thinking of writing my own version of TVOut to use only timer 2 and use less memory.  However, it has not been a priority.

pablogs9

Hey! I had the same troubble, so I started reading the TVout library and in the main .cpp there are some audio functions (someone sais that both libraries Eth and TVout use the pin 11) interfering with the Eth lib, so I deleted them. Now, the TVout works great at the same time that Eth, but the sound is unavailable.

I upload the .zip with the modified lib

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