Automated programming and testing jig built with Raspberry Pi

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[Doug Jackson] makes word clocks, and he must be doing quite a bit of business. We say that because he put together a programming and test bed for the clock circuit boards.

This is a great example to follow if you’re doing any kind of volume assembly. The jig lets the populated PCB snap into place, making all the necessary electrical connections. This was made possible by a package of goods he picked up on eBay which included rubber spacers to separate the board from the acrylic mounting plate, pogo pins to make the electrical connections, and a spring-loaded board clamp seen to the left in this image.

The switch in the lower right connects power to the board and pulls a Raspberry Pi GPIO pin high. The Python script running on the RPi polls that pin, executing a bash script which programs the ATmega169 microcontroller using the GPIO version of AVRdude. We looked through his Python script and didn’t see code for testing the boards. But the image above shows a “Passed” message on the screen that isn’t in his script. We would wager he has another version that takes the hardware through a self test routine.

We first saw one of [Doug’s] word clocks back in 2009 and then again a few months later. The look of the clock is fantastic and it’s nice to see the project is still going strong.

Gesture control uses WiFi doppler shift

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We’ve said it before: in the future simple interfaces will use nothing but your body. At least at first glance that’s the case with this WiFi-based gesture control system. If you have Internet at home you probably have a WiFi access point. That’s the first portion of the equation. The remainder is a way of measuring how the radio waves bounce off of your body. So far this is being done with Software-Define Radio (SDR) but researchers at University of Washington think it may be possible to build the technique into future WiFi devices.

The demo video shows this man waving his arm to adjust the volume of his home entertainment system. Intuition tells us that this would be impossible if your arm wasn’t the only thing in motion at the time. But that issue is quickly addressed. Multiple antennas can track multiple people at the same time. There is also consideration for false-positives. The system requires a moderately complex wake-up gesture sequence to prevent you from, say, accidentally turning on the stereo when you roll over in bed.

If you’re having trouble wraping your mind around this, consider this ultrasonic music player. The WiFi version does the same thing, but processing changes in the returning radio waves is much more complex.

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Incredible bow lathe work in Morocco

Bow lathes are a fairly old an simple contraption. A bow is used to rotate a block of wood back and forth while tools can be used to shape it, just like a modern lathe. Despite the fact that the wood is oscillating instead of spinning in one direction, the results are very smooth.

Watch as this street vendor shows his skills with the bow lathe. I find it quite impressive how well he uses his foot. You can tell he’s been doing this for a very long time. I was also pleasantly surprised when that ring popped free, I wasn’t expecting it.

[thanks Rudolph]

A binary clock that uses bulbs

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Based on his username, [Horatius.Steam], it’s not a surprise that he calls this project a “SteamPunk” style binary clock. But we think using neon  glow lamps in this binary clock is more of mid-century modern proposition. Either way, the finished look is sure to make it a conversation piece for your home.

He doesn’t give all that much information on the bulbs themselves. They seem to be neon glow lamps along the lines of a Nixie tubes. It sounds like they just need mains power (based on the image annotations for the relay board). The high voltage is switched by that collection of solid state relays. The controller board includes a DCF radio whose antennae is seen just below the controller. This picks up an atomic clock signal from Frankfurt, Germany. We think it’s a nice touch that he included a mechanical relay to simulate a ticking sound. That and the bulbs themselves can be turned off using the two switches in the base of the clock.

This seems like a good time to direct your attention to an artistic take on a Nixie clock.

 

Learning letters, particularly R, F, I, & D

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After [yohanes] picked up a toy at a yard sale – a Leap Frog Letter Factory Phonics – he thought he could do better. The toy originally asked a child to find a letter, and after digging one of 26 plastic characters out of a plastic tub and placing them on the Letter Factory’s sensor, would play a short musical ditty. [yohanes]’ version does the same, but because he made it himself it is infinitely more expandable.

The letters for [yohanes]’ version are RFID tagged. This, combined with a cheap RFID module and a bluetooth module means a Raspberry Pi can read RFID cards from across the room. From there, it’s a simple matter of writing up some Python to ask his toddler for a letter, reading the bits coming from a bluetooth, and keeping score.

The build isn’t over by a long shot. [yohanes] still needs to make his build multilingual by adding Indonesian and Thai. There’s also a possibility of adding a spelling game to make it more interesting.