Power Harvesting Challenge: Scavenge Some Power, Win Prizes

June 4, 2018 by Mike Szczys 26 Comments

It’s a brand new day as the Power Harvesting Challenge begins. This is the newest part of the 2018 Hackaday Prize and we’re looking for 20 entries who will each receive $1,000 and move onto the finals to compete for the top five spots, scoring cash prizes of $50k, $25k, $15k, $10k, and $5k.

Put simply, Power Harvesting is anything you can do that will pull some of the energy you need from a source other than wall-power or traditional battery tech. The most obvious power harvesting technologies are solar and wind. Ditch the battery in your doorbell for a solar panel, or turn your time-lapse camera rig into one that tops its battery with a tiny wind turbine. On the other end of the spectrum you could go nuts with chemistry and develop your own take on harvesting power from saltwater, or sip off the ambient RF waves all around us.

Every Idea Matters

We live in an amazing time as chip manufacturers have squeezed every low power trick out of their silicon dies that they possibly can. The Power Harvesting Challenge is the complement to those achievements: can we now squeeze as much energy out of non-traditional sources as possible to further reduce our energy footprints?

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Turning That Old Hoverboard Into A Learning Platform

June 3, 2018 by Anool Mahidharia No comments

[Isabelle Simova] is building Hoverbot, a flexible robotics platform using Ikea plastic trays, JavaScript running on a Raspberry Pi and parts scavenged from commonly available hoverboards.

Self-balancing scooters a.k.a. Hoverboards are a great source of parts for such a project. Their high torque, direct drive brushless motors can drive loads of 100 kg or more. In addition, you also get a matching motor controller board, a rechargeable battery and its charging circuit. Most hoverboard controllers use the STM32F103, so flashing them with your own firmware becomes easy using a ST-link V2 programmer.

The next set of parts you need to build your robot is sensors. Some are cheap and easily available, such as microphones, contact switches or LDRs, while others such as ultrasonic distance sensors or LiDAR’s may cost a lot more. One source of cheap sensors are car parking assist transducers. An aftermarket parking sensor kit usually consists of four transducers, a control box, cables and display. Using a logic analyzer, [Isabelle] shows how you can poke around the output port of the control box to reverse engineer the data stream and decipher the sensor data. Once the data structure is decoded, you can then use some SPI bit-banging and voltage translation to interface it with the Raspberry Pi. Using the Pi makes it easy to add a cheap web camera, microphone and speakers to the Hoverbot.

Ikea is a hackers favourite, and offers a wide variety of hacker friendly devices and supplies. Their catalog offers a wide selection of fine, Swedish engineered products which can be used as enclosures for building robots. [Isabelle] zeroed in on a deep, circular plastic tray from a storage table set, stiffened with some plywood reinforcement. The tray offers ample space to mount the two motors, two castor wheels, battery and the rest of the electronics. Most of the original hardware from the hoverboard comes handy while putting it all together.

The software glue that holds all this together is JavaScript. The event-driven architecture of Node.js makes it a very suitable framework to use for Hoverbot. [Isabelle] has built a basic application allowing remote control of the robot. It includes a dashboard which shows live video and audio streams from the robot, buttons for movement control, an input box for converting text to speech, ultrasonic sensor visualization, LED lighting control, message log and status display for the motors. This makes the dashboard a useful debugging tool and a starting point for building more interesting applications. Check the build log for all the juicy details. Which other products from the Ikea catalog can be used to build the Hoverbot? How about a robotic Chair?

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Servo Becomes Mini Linear Actuator

June 2, 2018 by Donald Papp 11 Comments

RC servos are a common component in many robotics projects, but [Giovanni Leal] needed linear motion instead of the rotary actuation that servos normally offer. The 3D Printed Mini Linear Actuator was developed as a way to turn a mini servo into a linear actuator, giving it more power in the process.

A servo uses a potentiometer attached to the output shaft in order to sense position, and the internal electronics take care of driving the motor to move the shaft to the desired angle. [Giovanni] took apart an economical mini servo and after replacing the motor with a 100:1 gear motor and using it to power a compact 3D printed linear actuator, he used the servo’s potentiometer to read the linear actuator’s position. As a result, the linear actuator can exert considerably more force than the original servo while retaining exactly the same servo interface. You can see one being assembled and tested in the video embedded below, which is part of [Giovanni]’s entry for The 2018 Hackaday Prize.

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This Is Your Last Chance To Design The Greatest Robotics Modules

June 1, 2018 by Brian Benchoff 2 Comments

It’s Friday, and that means this is your last weekend to get your project together for the Robotics Module Challenge in this year’s Hackaday Prize. We’re looking for tools for robots that blow the doors off what is commercially available. If you have a project in mind that adds sensors or capabilities to our fine electronic friends, enter it in the Hackaday Prize.

The Hackaday community has thrown itself full-force into the Hackaday Prize, and right now we’re getting very close to eight hundred projects entered in this year’s Prize. Next week, we’ll choose the top twenty projects entered during the Robotics Module Challenge to advance to the finals. Each of those twenty projects will be awarded $1,000 and be in the running to win the Grand Prize of $50,000 and four other top cash prizes.

This is your last chance to get in on the Robotics Module Challenge. For this Challenge, we’re looking for modules that can be used in robotics projects across the world. This could be a motor driver, sensor package, or even 3D printed tweels. Don’t wait — start your entry now.

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The Best Part Of Waking Up Just Got Better

May 31, 2018 by Kristina Panos 23 Comments

If you ask us, one of life’s greatest pleasures is sitting down with a nice, hot cup of something of coffee, tea or hot chocolate. Of course, the best part of this ritual is when the beverage has cooled enough to reach that short window of optimal drinking temperature.

Often times the unthinkable happens—we sip too early and get burned, or else become distracted by ~~watching cat videos~~ reading our colleagues’ Hackaday posts and miss the window altogether. What’s to be done? Something we wish we’d thought of: using the beverage’s heat to cool itself by way of thermal dynamics. For [Scott Clandinin]’s entry into the 2018 Hackaday Prize, he hopes to harness enough heat energy from the beverage to power a fan that will blow across the top of the mug.

[Scott] enlisted a friend to smith a thick copper slab in a right angle formation. The gentle curve of the vertical side pulls heat from the ceramic mug and transfers it to the heat sink of a CPU cooler. Then it’s just a matter of stepping up the voltage produced by the thermoelectric generator with a boost converter. Once he’s got this dialed in, he’d like to power it with supercaps and add a temp sensor and a microcontroller to alert him that his moment of zen is imminent. We’ll drink to that!

Supercapacitors In A Servo: The “Forever” Flashlight

May 30, 2018 by Ben James 21 Comments

The principle is well understood: use a motor in reverse and you get a generator. Using this bit of knowledge back in 2001 is what kick-started [Ted Yapo]’s Hackaday Prize entry. At the time, [Ted] was searching for a small flashlight for astronomy, but didn’t like dealing with dead batteries. He quickly cobbled together a makeshift solution out of some supercapacitors and a servo-as-a-generator, hacked for continuous rotation.

A testament to the supercapacitors, 17 years later it’s still going strong – leading [Ted] to document the project and also improve it. The original circuit was as simple as a servo, protection diode, some supercapacitors, and a LED with accompanying resistor; but now greater things are afoot.

A DC-DC boost converter enables constant power through the LED, regardless of the capacitor voltage. This is achieved by connecting the feedback pin of an MCP1624 switcher to an INA199 current-shunt monitor. The MCP1624 kicks in at 0.65V and stays active down to 0.35V. This is all possible due to the supercapacitors, which happily keep increasing current as voltage drops – all the way to 0.35V. Batteries are less ideal in this situation, as their internal resistance increases as voltage drops, as well as increasing with age.

When testing the new design, [Ted] found that the gears on his servos kept stripping when he was using them to charge capacitors. Though at first he attributed it to the fact that the gears were plastic, he realized that his original prototype from 2001 had been plastic as well. Eventually, he discovered the cause: modern supercapacitors are too good! The ones he’d been using in 2001 were significantly less advanced and had a much higher ESR, limiting the charging current. The only solution is to use metal gear servos

Want to read more about boost converter design? We have the pros and cons of microcontrollers for boost converters, or this neat Nixie driver for USB power.

Tiny $25 Spectrometer Aims To Identify Materials With Ease

May 29, 2018 by Donald Papp 59 Comments

Reflectance spectrometers work on a simple principle: different things reflect different wavelengths in different amounts, and because similar materials do this similarly, the measurements can be used as a kind of fingerprint or signature. By measuring how much of which wavelengths get absorbed or reflected by a thing and comparing to other signatures, it’s possible to identify what that thing is made of. This process depends heavily on how accurately measurements can be made, so the sensors are an important part.

[Kris Winer] aims to make this happen with the Compact, $25 Spectrometer entry for The 2018 Hackaday Prize. The project takes advantage of smaller and smarter spectral sensors to fit the essential bits onto a PCB that’s less than an inch square. If the sensors do the job as expected then that’s a big part of the functionality of a reflectance spectrometer contained in a PCB less than an inch square and under $25; definitely a feat we’re happy to see.