Raspberry Pi driven Polargraph exhibits high precision drawing ability

This polar graph draws some amazing shapes on a dry erase board. Part of that is due to the mounting brackets used for the two stepper motors and the stylus. But credit is also due for the code which takes velocity into account in order to plan for the next set of movements.

The Go language is used to translate data into step commands for the two motors. This stream of commands is fed over a serial connection between the RPi board and an Arduino. The Arduino simply pushes the steps to the motor controllers. The inclusion of the RPi provides the horsepower needed to make such smooth designs. This is explained in the second half of [Brandon Green's] post. The technique uses constant acceleration, speed, and deceleration for most cases which prevents any kind of oscillation in the hanging stylus. But there are also contingencies used when there is not enough room to accelerate or decelerate smoothly.

You can catch a very short clip of the hardware drawing a tight spiral in the video embedded after the break.

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Building a game clock for Go or Chess

[Matias] is just getting into hobby electronics and decided to push the limits of his skill by building this game clock. He comes from a software design background and that really shows through in the UI design seen in the video after the break. We enjoy the journey through his prototyping process which started with an Arduino and a breadboard, and ended with this standalone timer.

After building the first working prototype with four buttons and a character LCD, he migrated to a plastic ice cream container as an enclosure. This worked well enough, but the flimsy case needed an upgrade. As he looked toward the next version he decided to move to an Arduino Nano board to save on space. The rest of the components were soldered to some protoboard, with a pair of pin headers to receive the Nano. The finished board is the same length as the Nano and only about twice as wide.

The box was modeled on the computer (it looks like SketchUp to us be we could be wrong) then cut from pieces of Masonite. It hosts the character LCD with a pair of arcade buttons for each player to shift the time burden to his or her opponent. The middle button pauses the game, and there’s a trimpot on the back to adjust the screen contrast. [Matias] managed to include a surprising number of settings which will make this little box useful for a wide range of game types.

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PSP Go gets butchered (teardown)

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Not due to be released until the beginning of October, a PSP Go demo unit (shipped to G4TV) has already earned itself a teardown from [iFixit]. Among what was discovered:

- Once a few screws are removed, the battery is user replaceable (as-in: no soldering iron required)

- Wireless connectivity is only supplied through a 802.11b chip (no update to ‘n’, or even ‘g’, by Sony)

- Almost all chips are EMI-shielded (making them a bit more annoying to get to)

With a cheaper version of the PS3 ready to hit shelves, one can only wonder whether the relatively high price tag on this new PSP is worth it.

Update: It seems as though no party involved wanted the info leaked this early, which explains why the video and picture gallaries (up courtesy of Google) have been removed.

Update 2: The article (linked above) and video are now available. An explanation on why Sony had them remove the items for quite some time (plus some repair manuals) was posted by iFixit.

The GO sequencer

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[Guy John] sent in this cool sequencer project. He’s using the game Go as the input. A web camera pics up the location of the pieces on the grid and plots them in his sequencing software. You can see that it is still very much in progress, but it is coming along nicely. He openly admits that it may never be completely practical. There is still so much to be improved to get it even comfortably usable, such as motion detection to remove his hand from the mix when re locating the Go pieces. This project is very similar to the Skittles interface that we posted back in July.  It would be kind of interesting, though probably repetitive, to actually play a game of go and listen to the variations in the music while you play.