Audio Out As Video Out

[jeremiahb]

At this point i'm just trying to find projects to do with the myRIO, because if I don't, i've wasted almost $300. I got an idea to convert the myRIO in a vintage like video game console by programming games like pong, etc onto it. Is it possible to convert the audio out port into a simple composite video port? I would assume to change this, it would have to be done via FPGA.

[Kristoff2]

Hey jeremiahb,

You could probably use LVFPGA to generate analog video output.  You could also get an LCD with an SPI interface or some other digital interface and send data to it that way.

If you get something working post it here, I'd like to see it.

-Sam K

LabVIEW Hacker

Join / Follow the LabVIEW Hacker Group on google+

[jeremiahb]

I think I was a little bit over my head thinking that I can program the FPGA to generate Analog output. I have no clue how to use LabView. I'm a C/C++ & Java programmer. I might use an LED matrix instead.

[rocket]

Pick up some of the example projects and see what you can deploy to the myRIO.  You are very lucky to have an FPGA with LabVIEW for only $300.  There are endless things to play with and you could even expand your C knowledge by integrating call library function nodes into your code.

LabVIEW is great and the myRIO seems awesome.  I do not have the ability to play with one and purchased an ERIO myself to get a cheap at home FPGA to program with LabVIEW.  I use it for anyting from personal projects to R&D for work.  I believe the myRIO has a RTOS as well.  Incredilbly powerful and useful stuff when entering industry.

You could alwyas design an analog input yourself with custom signal conditioning and the ADC communication as well, that will keep you busy.  You can compare your results of a homeade ADC input with some of the built in ones on the myRIO.  But the example projects should give you plenty of ideas to mess around with.

Adam

[charlesy]

Hello,

You won't be able to drive standard composite video from the analog outputs on myRIO because they lack the bandwidth to update the frame buffer at any reasonable refresh rate. I believe you need 5 or 6 MHz of bandwidth for NTSC composite encoding. The audio outputs on myRIO are filtered to something between 20 kHz and 50 kHz. The analog outputs aren't artificially filtered, but are still limited to a couple hundred kHz. 

As Sam suggested, you can use the DIO lines to drive some representation of your video signal to a display controller that takes care of the analog video generation.

Good luck,

Charles Y.

National Instruments

[Sam_Sharp]

I've seen some projects for Arduino's that generate composite video out - I don't see any reason why you couldn't do something like that with a myRIO? I think it's done using just a couple of digital output pins.

Here are some links:

http://tronixstuff.com/2011/05/30/tutorial-video-output-from-your-arduino/

http://www.wayneandlayne.com/projects/video-game-shield/

http://forum.arduino.cc/index.php/topic,1996.0.html

http://www.instructables.com/id/TV-Out-with-Arduino/

I would also expect you to be able to do more with a myRIO with the FPGA! Interested to see how you get on though!

[0utlaw]

For posterity, it appears that at least one party managed 8-bit VGA using LV FPGA on a Virtex-II and an R-2R resistor ladder:

http://www.xroads-consulting.com/wp-content/uploads/2012/03/us_fpga.pdf

Based on that, it seems like getting something similar working on myRIO would be feasible. I've not seen it done, however.

Regards,

[timtamslam]

Not sure how helpful this is but, I was able to implement Pacman written in VHDL on an sbRIO 9636 using IP Integration nodes a while ago. The video solution I used was also DAC ladder logic. So, although its unlikely that you could implement Video out of the audio line, if you have the right IP for the game you want to run, it shouldn't be too crazy to run it on myRIO. It was relatively easy to put together a board for the resistor ladders. I would defintiely recommend getting a 90degree mount for the DB VGA connector though... having to break out the connector to connect to my bread board was annoying and introduced a fair amount of noise.

Here is an overview of the DAC board I used. Should give you a decent idea of how the ladder logic works out.

[HBNI]

This VGA  video out board for a DAC ladder is sold for use with an FPGA kit to produce video games

http://store.gadgetfactory.net/arcade-megawing