Better Batteries For Electronic Gadgets

September 6, 2015 by 46 Comments

We’re not using 9 Volt batteries to power our projects anymore; the world of hobby electronics has moved on to cheap LiPo batteries for most of our mobile power storage. LiPos aren’t the best solution, evidenced by hundreds of YouTube videos of exploding batteries, and more than a few puffy cells in our junk drawer. The solution? LiFePO4, or lithium iron phosphate cells. They’re a safer chemistry, they have low self discharge, and have more recharge than other chemistry of lithium cells.

LiFePO4 cells aren’t easy to deal with if you’re working with breadboard electronics, though. Most of that is because there aren’t many breakout boards for these cells. [Patrick] is working on changing that with his LiFePO4werd USB charger.

The concept is simple: use an off-the-shelf part for LiFePO4 batteries – in this case an MCP73123 – and make a board that charges the batteries with a USB port. It’s exactly the same idea as the many USB LiPo chargers out there, only this one uses a better battery chemistry.

[Patrick] is using a 550mAh battery for this project, but there’s no reason why it couldn’t be upgraded to a 18650-sized cell with more than 2000mAh stuffed inside. Add a boost converter to the circuit, and he’ll have the perfect power source for every portable electronics project imaginable.

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Hackaday Links: September 6, 2015

September 6, 2015 by 10 Comments

The MeArm is a cool little robot arm that can be controlled with just about any microcontroller. There’s a new version of it up on Thingiverse.

Here’s something to get kids interested in robotics: the GoBox is a robot kit with multiple ‘missions’ delivered monthly. The robot is based on the Raspberry Pi and Scratch – the Apple II and BASIC of today, I guess.

What happens when a popular electronics YouTuber completely debunks a product? Hundreds of dislikes appear on the YouTube videos he made. Hundreds of dislikes from Vietnam appeared on [Dave Jones]’ videos debunking the Batterizer. In fact, more people from Vietnam disliked the video than viewed it. Yes, weird YouTube dislike farms like this exist, and if you can do it on the Internet, you can also pay people to do it on the Internet.

The ESP8266 is slowly becoming a board that’s as easy to use as an Arduino. Now there’s a board that turns it into an Arduino.

The Vintage Computer Festival Midwest was last week,  and [chris537a] shot a video of all the cool stuff. [vikram4819] put an album up on imgur. Yes, someone was selling a Sparcbook for $300. I’m holding out for a PowerPC ThinkPad, though…

Washington DC area hackers, don’t forget to RSVP for the Hackaday Meetup on Saturday. Bring a hack to show off and spend the evening socializing with the Hackaday community. Check out the announcement post for more info.

CubeSat Challenge Winners Show Interesting Design Approaches

September 6, 2015 by 12 Comments

The winners are in for the GrabCad CubeSat Challenge, which asked designers to rethink the way that CubeSats are built. These tiny 10 cm square satellites are the hot thing in orbit, and the competition was looking for new ways to build and pack more into this tiny space. The winners offered some fascinating new approaches to building CubeSats, and some excellent design lessons that anyone can use.

The winner was FoldSat, by [Paolo Minetola]. His excellent design is a 3D printed folding case for a satellite that is built from just two 3D printed parts. The case can be snapped together and offers multiple ways to mount electronic components and sensors inside. [Paolo] estimates that it could save 40% time and 30% materials from existing CubeSat casings, which means more space inside and more time to build. It is an excellent example of how 3D printing can make things cheaper, easier and better, all at the same time.

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It’s An Upright Piano, It’s A Looper, It’s A Pi Project

September 6, 2015 by 6 Comments

We don’t really get out much, but we have noticed that there are brightly painted upright pianos in public places these days. Research indicates that these pianos are being placed by small, independent local organizations, most of which aim to spread the joy of music and encourage a sense of community.

[Sean and Mike] took this idea a couple of steps further with Quaver, their analog looping piano. Both of them are maker/musicians based in Lancaster, Pennsylvania, which happens to be a hot spot for public pianos. [Sean and Mike] often stop to play them and wanted a good way to capture their impromptu masterpieces. Quaver is an antique upright that has been modified to record, save, loop, and upload music to the internet. It does all of this through a simple and intuitive user interface and a Raspi 2. Quaver works a lot like a 4-track recorder, so up to four people can potentially contribute to a song.

The player sits down, cracks their knuckles, and presses our personal favorite part of the interface: the giant, irresistible record button. A friendly scrolling LED matrix display tells them to start playing. Once they are satisfied, they press the button again to stop the recording, and the notes they played immediately play back in a loop through a pair of salvaged Bose speakers from the 1980s. This is just the beginning of the fun as you play along with your looping recording, building up several voices worth of song!

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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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