Year: 2015

Hams Talk Digital

September 6, 2015 by 45 Comments

Morse code qualifies as a digital mode, although organic brains are somewhat better at copying it than electronic ones. Ham radio operators that did “phone” (ham-talk for voice) started out with AM modulation. Sometime after World War II, there was widespread adoption of single side band or SSB. SSB takes up less bandwidth and is more reliable than AM modulation. On the digital side, hams turned to different and more sophisticated digital transmission types with computers pushing bandwidth down and reliability up. However, a recent trend has been to encode voice over ham radio–sort of VoIP with radio instead of Ethernet–using an open source program called freedv.

[AA6E] made a very informative video where he carries on a QSO (a conversation) with a distant station using freedv. What makes it interesting, is towards the end when the two stations switch to regular SSB. The difference is dramatic and really points out how even with less bandwidth (roughly 3 kHz for SSB vs 1.25 kHz), the digital mode is superior. The freedv software (available for Windows or Linux) compresses audio to 700-1600 bits per second and spreads it over 16 QPSK signals.

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Better Racing With Power Wheels

September 6, 2015 by 6 Comments

For the last few months, teams across the US have taken old Power Wheels and other electric vehicles meant for children and turned them into racing machines capable of flying around the track at speeds pf over 30 miles per hour. How do you take the plastic chassis of a kid’s toy and turn it into a Power Racer? [Dane] from team Chibi-Atomic-Thing tells us how.

In classic Power Racing Series fashion, this year’s build began with last year’s chassis. At the 2014 NYC Maker Faire, a weld on the steering linkages failed, necessitating some quick work to replace some bad welds. Poor fabrication wasn’t the only shortcoming of last year’s car; the rear axle was fixed, the brakes were terrible, and the gearbox wasn’t quite as good as it could be.

The team had a few months to make the necessary changes for this season’s races. Because they were adding advanced and arcane technology known as a differential this year, a second disc brake holster would need to be fabricated for the other rear wheel. A new motor controller was added, but the team is mum on why exactly they need an eight-speed gearbox when the longest straight on the track is about fifty feet.

The answer to why a tiny electric car needs more gears than a clock is for now, at least, unknown. Hopefully it will be revealed at the next Power Racing Series race at the NYC Maker Faire in a few weeks. Until then, check out the video of the 2015 Detroit race below.

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Hackaday Prize Semifinalist: Picking Up Litter With Robots

September 5, 2015 by 9 Comments

On beaches, in parks, and in [BDM]’s back yard, there’s a lot of liter everywhere. The normal solution to this problem is to hire someone or find some volunteers to pick up all this trash. We’re living in the future, though, and that means robots. For his Hackaday Prize entry, [BDM] is building a robot that picks up trash.

A robot that picks up litter is a very, very interesting problem. It can’t be controlled by a person, or else it would be more efficient to just get out there and kill your back picking up bottles. This means it must work autonomously, and that means identifying litter, picking it up, and disposing of it.

For the identification part of the problem, [BDM] is using computer vision that captures an RGB image and discriminates against natural objects. Right now the computer vision is far from perfect, but it does a very good job, all things considering.

The next biggest problem is picking the trash up and disposing of it. For this, [BDM] has repurposed a Power Wheels and attached a DIY robot arm. It’s not a very powerful arm, and a children’s toy probably isn’t the best platform, but it is the start of something very, very cool.

You can check out [BDM]’s video for the project below.

The 2015 Hackaday Prize is sponsored by:

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ESP8266 Web Server Farm

September 5, 2015 by 15 Comments

There seems to be a hacker maxim that whatever gadget you are working with, it would be better to have several of them running together. That might explain the ESP8266 web server farm that [Eldon Brown] has built. Yup, a web server farm made from three of everyone’s favorite WiFi dongle, the humble ESP8266.

Eldon’s server farm is currently serving web pages here, running on three ESP8266 boards. Or it was before this posting reduced it to a smoking ruin (screenshot below just in case). Each module is running a dynamic web page and some clever programming he came up with that makes transferring data over these cheap devices quicker.

His page isn’t anything too fancy but it is impressive considering it is running on about $30 worth of hardware, including the breadboard it is wired into. The page includes dynamically-generated graphics and some back-end stuff. I don’t think that it will replace any LAMP servers anytime soon (the ESP8266 took about 2.6 seconds to generate the page below), but it is an impressive hack. [Eldon] has made the full code of the web server that is running the pages available. So, lets add web server farm to the list of things that this neat little device can handle, next to plant weigher, Bitcoin price tracker, MP3 player and many more…

Thanks to [PuceBaboon] for the tip!

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Crystal Radio: It’s A Match!

September 5, 2015 by 10 Comments

A crystal radio is often a kid’s first introduction to building something electronic. [Billy Cheung] is a crystal radio builder who wants to “make crystal radios as easy to use as regular radios.” He’s built many sets, but his latest is one that not only fits in a matchbox, but uses the matchbox as a variable tuning inductor.

There’s no oatmeal box in this design and just a few components. The matchbox contains some ferrite rods and two different windings. By moving the inner part of the matchbox, you can tune different stations. Although the design calls for two fixed capacitors [Billy] found he had enough self resonance (presumably from stray capacitance) that omitting them didn’t hurt his reception of strong signals.

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arduino alarm panel

Upgrading Your Alarm System With An Arduino

September 5, 2015 by 17 Comments

When [Doug] moved into his new house, he found an old alarm panel set up — but it had no monitoring service any more. Not wanting to pay a monthly fee to have it setup, he decided to try interfacing an Arduino with the system in order to push events to the net!

The cool thing is he was actually inspired by another similar project we shared on Hackaday a few years ago entitled Bending a Home Security Control Panel to Your Will. But that project only showed you how to interface the Arduino with the keypad — [Doug] went the extra mile and interfaced directly with the control board for more features.

He’s using an Arduino Uno and an Ethernet breakout board to hook it up to the network. This allows him to send text messages to himself when the alarm system is armed, disarmed, or triggered. All the code is available on GitHub in case you also have a DSC 1550 alarm system.

It’s a pretty slick hack, so don’t forget to check out the video after the break.

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How To Make A Hugo (Base)

September 5, 2015 by 25 Comments

A lot of hackers like science fiction. If you aren’t one of them, you might not know that the Hugo is a prestigious science fiction award handed out at the World Science Fiction Convention every year. The statue looks like a rocket ship, but every year the base the rocket ship rests on is different. Kinetic sculptor [gfish] realized the convention would be in Spokane (his hometown and near his current residence) and decided to enter the competition to create the bases. He won, so the 2015 Hugos all have [gfish’s] bases on them and it’s pretty neat that he’s shared the process he used to make them.

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