Composite video with MSP430 chip

[NatureTM] used part of the Thanksgiving holiday to get composite video output working with an MSP430 microcontroller. He’s using one of the chips that came with the TI Launchpad, which is a big hardware limitation because of the relatively small code memory and RAM. The chip displays one still image at a resolution of 192×40 pixels. Still, this is a great way to learn about composite video signals, as a lot of other projects use a TVout library to save you the headaches. All you’ll need is a TI Launchpad, a 16 MHz crystal oscillator, two resistors, and an RCA jack. Dig through the code and see what a great job [NatureTM] did of offloading as much work onto the chip’s peripherals as possible.

Microscope camera adapter

[Ben Krasnow] is capturing some great snapshots using a microscope adapter and some tricks. The camera attachment is just a lens adapter ring with a tube added. Unlike other microscope imaging hacks we’ve seen he used a real microscope but found that the pictures had a bit of light distortion to them. The camera sensor was picking up a glare reflected on the inside of the black tube. By adding a washer and repositioning the apparatus he got over that hurdle. The final part of the puzzle is image processing. By taking several pictures at different focal lengths and compositing them he gets killer photos like the compound eyes of that house fly seen above.

DIDJ composite video out

[Nirvous] managed to get composite video out working on the DIDJ. He knew that the CPU had the ability to generate the signal, and that similar devices already had this capability. After studying some DIDJ teardowns he figured out which connection on the processor should provide the appropriate signal. Next was the firmware side of things and after sifting through a lot of code he was pleased to find a flag that looked like it would enable video out. Some cross-compiling, soldering, and a low-pass filter got it to work.

If you’ve been hacking around on the device you might try this. The CPU uses a ball grid array so soldering is a bit difficult. We covered a BGA soldering trick that might be just the thing so check it out before you retreat into your soldering-fortress of solitude.

Phasor A/V PAL demo uses ATmega88

Above is a new demo video called Phasor developed by [Lft]. It is run from an AVR ATmega88 and a few passive components, and the result is pretty amazing. [Lft] goes into detail about the tricks he used to get this up and running. The chip is clocked at 17.73447 MHz which is exactly four times the frequency of the PAL color carrier wave which allows him to fake a smooth signal. He also uses a timer trick to get the voltages that he needs. The work done here is beyond hardcore and quite frankly we can’t believe he managed to fit all of this into 8.5 KB of program space with just 1 KB or RAM. We wonder if there’s enough room there to add sound and color to the AVR Tetris project.

[Thanks Sprite_tm]

More AVR Tetris

[Ben] built an AVR based Tetris game that uses a TV as the display. He linked his project in a comment from the AVR Tetris project featured last week. His work taps the power of his own tvText library to handle the composite video out. Using a TV takes all of the hardware work out of the equation, leaving just the composite jack and a few buttons to connect to the ATmega168 and its 20MHz clock. We’ve embedded the game play video after the break. It’s black and white but also clean and crisp.

[Ben] didn’t include music with his build but another commenter, [Eric], has started to work on that. We can’t help but think that they both should have tipped us off sooner about their projects.

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Composite video output from chumby

[bunnie] posted this pretty slick way of getting composite video out of a Chumby. The Chumby is an open source connectivity device that has already seen some decent hacking. This modification, done by [xobs] isn’t too difficult. It only requires patching into some pads on the motherboard and loading a custom kernel to support the external output.

S-video from an Atari 2600


[Ben Heck] posted this writeup about getting S-Video/composite out of an Atari 2600. This is actually the hack of [Longhorn Engineer], who showed it to [Ben] at a recent event. If any of you have tried to play these classics on a modern TV you may have found it to be quite difficult. If you manage to get it physically connected, through adapters and such, you may still have video issues. This alleviates that issue completely. After you solder this in, your Atari has native composite/S-video. As you can see in the video after the break, it seems to work pretty well.

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