Dual-mode Avalanche And RF Random Number Generator

October 31, 2014 by 28 Comments

[Paul] designed a new open-hardware RNG (random number generator) that includes two sources of entropy in a small package. The first source of entropy is a typical avalanche diode circuit, which is formed by a pair of transistors. This circuit creates high-speed random pulses which are sampled by the onboard microcontroller.

What makes this design unique is a second entropy source: a CC2531 RF receiver. The RF receiver continuously skips around channels in the 2.5Ghz band and measures the RF signal level. The least-significant bit of the signal level is captured and used as a source of entropy. The firmware can be configured to use either source of entropy individually, or to combine both. The firmware also supports optionally whitening the entropy byte stream, which evens out the number of 1’s and 0’s without reducing entropy.

The OneRNG uses the USB-CDC profile, so it shows up as a virtual serial port in most modern operating systems. With the rngd daemon and a bit of configuration, the OneRNG can feed the system entropy source in Linux. [Paul] also has a good writeup about the theory behind the entropy generator which includes images of his schematic. Firmware, drivers, and hardware design files are open-source and are available for download.

Raspberry Pi Brings New Life To Some Old Dinosaurs

October 31, 2014 by 7 Comments

Reprogramming the behaviors of a person-sized animatronic dinosaur would have to be among the coolest opportunities to be presented with… This is exactly what [Dr. Lucy Rogers] and a group of fellow techies were tasked to accomplish for the Blackgang Chine park located on the Isle of Wight in the UK.

dino1Before the group arrived, the native dinos didn’t do much else than run a preprogrammed routine when triggered by someone’s presence… which needless to say, lacks the appropriate prehistoric dynamism. Seeing that their dated wag, wiggle, and roar response could use a fresh breath of flair, the park’s technical projects coordinator [Mark Butler] began adapting one of the dinosaur’s control boxes to work with a Raspberry Pi. This is when [Lucy] and her group were called upon for a two-day long excursion of play and development. With help and guidance from Raspberry Pi expert, [Neil Ford], the group learned how to use a ‘drag and build’ programing environment called node-RED in order to choreograph new movement sequences for two of the smaller dinosaurs provided for use. The visual nature of node-RED helped those of the Blackgang staff with little programming experience understand the code at work, which aided in their training. Now they can reprogram the dinosaurs with new actions on the fly if needed.

The Pi in the end turned out to be a cost-effective solution which will give the robot dinosaurs a longer, more fulfilling lifespan to roar and frolic on their island home. Check out this video by [Debbie Davies] to see more…

Thanks Ed, for spotting this one!

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A Better Anonabox With The Beaglebone Black

October 31, 2014 by 29 Comments

A few weeks ago, Anonabox, the ill-conceived router with custom firmware that would protect you from ‘hackers’ and ‘legitimate governments’ drew the ire of tech media. It was discovered that this was simply an off-the-shelf router with an installation of OpenWrt, and the single common thread in the controversy was that, ‘anyone can build that. This guy isn’t doing anything new.’

Finally, someone who didn’t have the terrible idea of grabbing another off the shelf router and putting it up on Kickstarter is doing just that. [Adam] didn’t like the shortcomings of the Anonabox and looked at the best practices of staying anonymous online. He created a Tor dongle in response to this with a Beaglebone Black.

Instead of using wireless like the Anonabox and dozens of other projects, [Andy] is using the Beaglebone as a dongle/Ethernet adapter with all data passed to the computer through the USB port. No, it doesn’t protect your entire network; only a single device and only when it’s plugged in.

The installation process is as simple as installing all the relevent software, uninstalling all the cruft, and configuring a browser. [Adam] was able to get 7Mb/sec down and 250kb/sec up through his Tor-ified Ethernet adapter while only using 40% of the BBB’s CPU.

Push Button, Receive Candy (or Death)

October 30, 2014 by 14 Comments

Will you be handing out candy on Halloween? Maybe you have a party to attend or kids to take around the neighborhood and can’t be home to answer the bell. You don’t want to be The Dark House With No Candy, ’cause that’s a good way to get TP’d. We’re not exactly sure what [Ben]’s catalyst was aside from trying to avoid tempting would-be thieves with an unattended bowl on the porch. Whatever the reason, we’re happy to present Candy or Death, his gamified candy (or death)-dispensing machine.

Okay, so it only dispenses candy for now. [Ben] hasn’t quite worked the kinks out of his death ray. He designed it to sit behind a porch-facing window so it can’t be messed with. All trick-or-treaters can do is push the button and take the candy. It’s built around a cereal dispenser that’s modified to be cranked by a piece of round rod driven with a NEMA-17 stepper motor and an Arduino Uno with a motor shield. The candy slides down a length of aluminium rain gutter into a plastic stacking bin, and the whole thing is built into a nice wood frame.

A few adjustments were necessary to keep it from jamming. The dispenser’s hopper uses rubber blades to govern the flow, and he ended up removing a few and trimming the others. [Ben] has an album up of all his build pics and put his code on the gits. Stick around to see videos of the machine from the front and rear.

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Improving The Parallax Propeller In An FPGA

October 30, 2014 by 14 Comments

The Parallax Propeller is an interesting chip that doesn’t get a lot of love, but since the entire chip was released as open source, that might be about to change: people are putting this chip inside FPGA and modifying the binaries to give the chip functions that never existed in the original.

Last August, Parallax released the source for the P8X32A, giving anyone with an FPGA board the ability to try out the Prop for their own designs. Since then, a few people have put some time in, cleaning up the files, unscrambling ROM images, fixing bugs, and all the general maintenance that an open source microcontroller core requires.

[Sylwester] has grabbed some of the experimental changes found on the Parallax forum and included them as a branch of the Propeller source. There is support for a second 32-bit port, giving the new chip 64 I/O pins, multiply instructions, video generators, hard-coded SD card libraries, and a variant called a microProp that has four cores instead of eight.

You can grab all the updated sources right here and load them up on a DE0 Nano FPGA board. If you’re exceptionally lucky and have the Altera DE2-115 dev board, you’ll also be able to run the upcoming Propeller 2.

Flaming Jack-o’-lanterns Light Up The Night

October 30, 2014 by 14 Comments

[misterdob] wanted to spice up his Halloween decor, so he built these flaming concrete jack -o’-lanterns to decorate his walkway. He started with the classic plastic jack-o’-lanterns that trick-or-treaters have been using to collect candy for years. [misterdob] filled the plastic pumpkins halfway with concrete mix, then dropped in metal coffee cans. He then filled the pumpkins up to the top with concrete, shaking them up a bit to avoid air pockets.

Once the concrete had set, [misterdob] cut away the plastic revealing nearly perfect concrete duplicates. He used acid stain to color his creations – though it looks like he missed a spot or two.

We have to disagree with [misterdob’s] choice of fuels. In fact, we think he was out of his gourd when he picked gasoline for his flaming pumpkins. Seriously though, gasoline is a horrible choice for a fire pot like this for a multitude of reasons. Gas has a particularly foul odor and its fumes are explosive. If a Halloween prankster were to try kicking one of the pumpkins over, not only would they have a broken foot, they’d also be covered in burning gas.

Thankfully, the folks on [misterdob’s] Reddit thread had better fuel suggestions – citronella torch cans with lamp oil and wicks, kerosene, or gel fuel would be better suited for these hot pumpkins.

If you still don’t believe how dangerous gas and its fumes can be, check out this video of a bonfire gone wrong (language warning).

Piezo Vacuum Pump For Lightweight Pick And Place

October 30, 2014 by 21 Comments

If you’re building a pick and place machine, or even just a vacuum pen, you’ll need some way to pick up tiny part. This means something that sucks, aquarium tubing, and everything that goes with that. A few months ago, [Wayne] found an interesting device called a Micro Blower that will blow small amounts of air from a small, lightweight device. A few modifications later, and he had a piezoelectric vacuum pump for picking up tiny parts.

The Micro Blower [Wayne] found is available on Mouser for about $45, but this device blows. To turn it into something that sucks, he would need to find a way to block up the input side of the pump so it could draw a vacuum. Eventually settling on mounting the blower inside a stack of foam board, [Wanye] glued on a 20 gauge needle and was able to suck up 0603 SMD parts.

The new piezoelectric sucker is extremely light, and the power draw is very reasonable: 18V and 20mA. This would be a great device to mount to a certain pick and place machine without having to run vacuum lines through the mechanics of a motion platform. Video below.

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