Designing, Simulating And Testing A Simple Radio Duty-Cycling Protocol For Contiki

January 9, 2014 by 1 Comment

A few days ago we featured [Marcus]’ Contiki port to the TI Launchpad, Contiki being an open source operating system dedicated to the Internet of Things created by [Adam Dunkels] at the SICS in Sweden. Part of [Marcus]’ work involved designing a simple radio duty-cycling protocol that achieves 3% idle listening duty cycle while allowing for an average 65ms latency with no prior contact or synchronization.

As a few readers may already know, it takes quite a lot of power for a wireless device to listen/send data. A platform therefore needs to have an algorithm that minimizes power consumption while allowing a (regular) planned data transfer. After creating his protocol named SimpleRDC, [Marcus] first simulated it using the Cooja simulator in order to check that it could perform as desired. He then implemented a real life test and checked the protocol’s performance by sniffing the SPI lines connecting his MSP430 to the wireless module and by monitoring the platform power consumption with his oscilloscope and a shunt resistor.

A Transparent 7-Segment Display

January 9, 2014 by 40 Comments

Though [Connor] labels it as a work in progress, we’re pretty impressed with how polished his transparent 7-segment display looks. It’s also deceptively simple.

The build uses a stack of seven different acrylic panes, one in front of the other, each with a different segment engraved onto its face. The assembly of panes sits on a small mount which is placed over seven rows of LEDs, with 5 LEDs per row. [Connor] left an air gap between each of the seven individual acrylic panes to clearly distinguish which was lit and to match the separation of the LED rows. To display a number, he simply illuminates the appropriate LED rows, which scatter light across the engraved part without spilling over into another pane.

You can find a brief overview and some schematics on [Connor’s] website, and stick around for the video demonstration below. We’ve featured [Connor’s] work before; if you missed his LCD data transfer hack you should check it out!

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OliveR The Programmable Cooking Robot

January 9, 2014 by 46 Comments

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[Oak Robotics] is putting the finishing touches on their programmable cooking robot named OliveR.

It’s not about to make you a souffle (but where did it get the milk?), but it does aim to take the boring parts out of cooking — namely the tedious stirring, adjusting temperatures and the timing of ingredients. While that does make it significantly less impressive than the original title suggests, the team has a blog running of successful recipes — They’ve made some excellent chicken curry, Korean beef, and even Jambalaya!

The team is currently looking for beta testers, and while we’re not too sure what this even entails, you can certainly send them an email and find out! To see a demonstration of OliveR’s cooking skills, hang around after the break.

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From EPaper Badge To Weather Station

January 8, 2014 by 7 Comments

ePaper Weather Station

[Jeremy Blum] converted his 2013 Open Hardware Summit badge, also known as the BADGEr, into an ePaper weather station. We’ve looked at the 2013 OHS badge in the past, and the included open source RePaper display makes it an interesting platform to hack.

To fetch weather data, the badge is connected to a Raspberry Pi using an FTDI cable. A Python script uses the Python Weather API to poll for weather data. It then sends a series of commands to the BADGEr using pySerial which selects the correct image, and inserts the current weather data. Finally, a cronjob is used to run the script periodically, providing regular weather updates.

If you happen to have one of the badges, [Jeremy] has provided all of the files you’ll need to build your own weather station on Github. Otherwise, you can take a look at the RePaper project and WyoLum’s eReader Arduino Library to build your own ePaper project.

A Blindingly Bright Larson Scanner

January 8, 2014 by 31 Comments

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This hulking monument to illumination is [DJJules’s] 6-foot-long Ultimate Larson Scanner. If you’re scratching your head in confusion, the Larson Scanner is the ever-popular scrolling LEDs seen on KITT (the car) from Knight Rider and on Cylons in Battlestar Galactica (1978), named after the creator of the series.

[DJJules’s] iteration consists of sixteen 10W LEDs, each mounted on a heat sink which bolt on to a 6′ long piece of angle aluminum sourced from a local hardware store. He used a basic MOSFET constant current driver for each LED, attaching the MOSFETS to the heat sink with 4-40 screws. Each LED module then connects to a TLC5940 LED driver breakout board from Sparkfun, which plugs into an Arduino Pro Mini.

Check out the Instructables page for the source code and other important details, including safely powering the build (the LEDs can draw around 1A each), then grab your sunglasses and stick around for a quick video below.

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A Tiny Clock With A Retro Display

January 8, 2014 by 18 Comments

After having ported Contiki to his TI Launchpad platform, [Marcus] was eager to do something with it. He therefore built a simple clock with a vintage HPDL-1414 “smart four-character 16-segment alphanumeric display” and a msp430g2553.

The result that you can see above is powered over USB, includes a 3.3V LDO linear voltage regulator as well as a button, a LED, a crystal, and several passive components. Fortunately enough, the 5V-powered HPDL-1414 display accepts 3.3V logic at its inputs, avoiding the need for level translators.

The clock program is running on the ported Contiki 2.6 that you can find on his Github repository. [Marcus] is considering using a vibration motor to buzz every 20 minutes during work hours as a reminder for the 20-20-20 rule to battle eye fatigue: every 20 minutes, look at something 20 feet away for 20 seconds. A video of the system in action is embedded after the break.

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3D Printering: Making A Thing With Blender, Part II

January 8, 2014 by 49 Comments

printering

So you have a 3D printer and need to print something of your own design. That’s a problem if you don’t know how to create and edit 3D objects.  In this post, we’re continuing our previous misadventures with Blender by making a ‘thing’ torn from a very old book on drafting.

Previously, we’ve made the same part in other 3D design packages. Here’s some links to those other ‘Making a Thing’ posts:

We’ve already done half the work to make a ‘thing’ in Blender, so now it’s time to finish the job. Check out the rest of the tutorial below.

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