This Smart Pill Uses A Stomach Acid Battery

July 7, 2018 by Steven Dufresne 34 Comments

[Curt White] is working on a smart pill whose copper-zinc battery will use his own stomach acid as the electrolyte. It’s not that unusual of an idea, MIT tested a similar approach in a pig. It’s also better than using lithium ion batteries, something we covered in this PSA.

His starting point is a small, hacked activity tracker with its Nordic nRF51822 ARM Cortex-M0 and Bluetooth LE SoC. Most everything else is removed. The battery electrodes are sewn onto a plastic mesh cut to the activity tracker’s dimensions. Three coin type super capacitors and a boost converter sit between the battery and the SoC.

He uses the Bluetooth LE for communication, sort of. BLE devices constantly transmit information about themselves and it’s this which you see when scanning for available devices. Included in that transmission is a UUID (Universally Unique Identifier) and a name (e.g. “smartpillxyz”). He has the pill transmit data by putting it in that name. This saves power by minimizing the time which the pill’s Bluetooth radio is turned on. The smartphone app extracts the data from these transmissions without ever connecting.

His goal is to monitor the voltage and the maximum current. This will tell him if his stomach acid battery works and what can be powered by it. First tests will use regurgitated gastric fluid and then later he’ll swallow the pill himself. As he puts it, why not, “people swallow and pass all kinds of weird stuff without a problem.” Thay may sound cavalier but judging by his hackaday.io page, he’s doing his homework.

DIY Socket For Prosthetics Contains Power Supply, Charger

July 6, 2018 by Donald Papp 4 Comments

Innovation in prosthetics is open to anyone looking to enhance the quality of life, but there’s an aspect of it that is sometimes under-served. The DIY Prosthetic Socket entry to the Hackaday Prize is all about the foundation of a useful prosthesis: a custom, form-fitting, and effective socket with a useful interface for attaching other hardware. While [atharvshringaregt] is also involved with a project for a high-tech robotic hand with meaningful feedback, socket fitting and design is important enough to be its own project.

The goal is not just to explore creating these essential parts in a way that’s accessible and affordable to all, but to have them include a self-contained rechargeable power supply that can power attachments. Thoughtful strap placement and a power supply design that uses readily available components with a 3D printed battery housing makes this DIY prosthetic socket a useful piece of design that keeps in mind the importance of comfort and fitting when it comes to prosthetics; even the fanciest robot hand isn’t much good otherwise.

A Flashlight Powered By Your Hot Little Hands

July 5, 2018 by Kristina Panos 18 Comments

We are smack-dab in the middle of our Energy Harvesting Challenge, and [wasimashu] might have this one in the palm of his hand. Imagine a compact flashlight that doesn’t need batteries or bulbs. You’d buy a 10-pack and stash them everywhere, right? If there’s nothing that will leak or break or expire in your lifetime, why not have a bunch of them around?

Infinity uses nothing but body heat to power a single white LED. It only needs a five-degree temperature difference between the air and your hand to work, so it should be good in pretty much any environment. While it certainly won’t be the brightest light in your collection, it’s a whole lot better than darkness. Someday, it might be the only light around that works.

As you might expect, there’s a Peltier unit involved. Two of them, actually. Both are embedded flush on opposite sides of the hollow aluminum flashlight body, which acts as a heat sink and allows air to pass through. After trying to boost the output voltage with a homemade feedback oscillator and hand-wound transformers, [wasimashu] settled on a unipolar boost converter to reach the 5V needed to power the LED.

[wasimashu] has made it his personal mission to help humanity through science. We’d say that Infinity puts him well on the way, and can’t wait to see what he does next.

Nonpareil RPN HP-41 Calculator Build

July 4, 2018 by Rich Hawkes 21 Comments

The early HP Reverse Polish Notation calculators have a special place in the hearts of engineers and tinkerers as there are lots of projects involving them. They haven’t been produced in decades, but [Chris Chung] has used some open source code to create DIY hardware version of the HP-41 Reverse Polish Notation (RPN) calculator.

The open source code behind the calculator is the Nonpareil High-Fidelity Calculator Simulator, and [Chris] has used it along with a custom designed readout and PCBs to create a working prototype. The simulator uses the original byte code of the HP-41 so the its behavior is exactly the same as the original calculator.

[Chris] has designed the PCBs so that the buttons and the screen are separate and join together. This neat idea means that he can try out different screens or different button PCBs and mix-and-match to find the combination that works best. He’s also designed a 3D printed case for the calculator. He does prefer using the bare buttons on the board to the 3D printed ones he printed for use with the case.

We love calculators here so there have been a bunch of articles over the years. Check out the documentation that comes along with this open source calculator, or check out this pocket calculator that emulates two other pocket calculators!

Continue reading “Nonpareil RPN HP-41 Calculator Build” →

Roboshield Helps Your Robot Walk And Talk

July 3, 2018 by Lewin Day 3 Comments

The joy of building robots comes from being able to imbue them with as much or as little personality and functionality as you wish during the design and build process. While creative flair and originality is always a good thing, there’s a lot of basic needs many robots have in common with each other, so where possible it’s good to avoid reinventing the wheel so more time can be spent on more advanced features. Roboshield aims to help make the basics easy so you can let your robot freak flag fly!

At its core, it’s an Arduino shield that packs in a host of hardware to get your robot up and running. As far as motion is concerned, a PCA9685 module is used to allow the control of 8 servos, plus there’s a TB6621FNG dual motor speed controller that offers both speed control and forward/reverse. That’s enough to get your electronic buddy scooting about the floor and waving its arms in the air.

The party piece, however, is the Vstamp text-to-speech module. This device produces a beautiful cliche electronic voice, which your robot is legally required to use to recite Asimov’s Laws of Robotics. Overall, it’s a tidy project that can take the hassle out of getting your robot design up and running, leaving you to focus on the fun bits like death rays and tractor beams. We can’t wait to see it powering the next wave of sassy DIY robots.

Video Quick-Bit: The Things That Move Robots

July 2, 2018 by Mike Szczys 1 Comment

Magenta Strongheart returns for a look at some of the coolest robotic entries from this year’s Hackaday Prize. Each of these answered the challenge for modular designs that will help supercharge new robot projects.

We think that cheap and abundant motor designs are poised to revolutionize robotics and several of the entries thought along those same lines. [Masahiro Mizuno] came up with a great 3D printed servo design based around a 6mm DC motor. Also in this ballpark, a team of two — Giovanni Leal and Jonathan Diaz — used 3D printing to turn some tiny metallic servos into linear actuators.

Picking stuff up is a difficult thing for a machine to do. We’ve long enjoyed seeing jamming grippers which do it with an inflatable bladder around a granular material (watch the video… it’s amazing). Two of these were demonstrated as part of the challenge. The Universal Jamming Gripper focuses on the entire mechanism, while Programmable Air took aim at the pneumatic actuation system and can adapt to other soft-robotics uses.

Rounding out this update, make sure to take a peek at the PCB stepper motor [Bobricius] built after being inspired by [Carl Bugeja’s] PCB motor. You’ll also want to see the entry that is taking on industrial farming. Imaging slow-rolling behemoths that use computer vision and spinning tillers to take care of weeds, cutting down on herbicide use.

Right now we’re in the thick of the Power Harvesting Challenge. Show us how you’re getting power from an interesting source and you’ll be on the way to the finals. Twenty power harvesting entries will get that honor, along with a $1,000 cash prize. The five top entries of the 2018 Hackaday Prize will split $100,000!

Raspberry Pi Zero Stepper Driver, First Of Many Modules

July 1, 2018 by Donald Papp 32 Comments

The Raspberry Pi in general (and the Zero W model in particular) are wonderful pieces of hardware, but they’re not entirely plug-and-play when it comes to embedded applications. The user is on the hook for things like providing a regulated power source, an OS, and being mindful of proper shutdown and ESD precautions. Still, the capabilities make it worth considering and [Alpha le ciel] has a project to make implementation easier with the Raspberry Pi Zero W Stepper Motor Module, which is itself part of a larger project plan to make the Pi Zero W into a robust building block for robotic and CNC applications.

[Alpha le ciel] is building this stepper motor module as the first of many Raspberry Pi hats meant to provide the Raspi with the hardware for robotics applications. This module, in particular, features two A4988 stepper motor drivers, a connector for a power supply or battery providing 7-20V, and a buck converter to bring that power down to the 5V needed by the Pi itself. All the relevant pins are broken out onto the Pi’s GPIO header, making this module the simplest way possible to add a pair of motors to a Pi. What does that mean? Printers or self-balancing robots, really whatever you want.

A stepper driver that conforms to the footprint of the Pi Zero is a good start, and the larger concept of creating additional modules is a worthy entry to the Hackaday Prize.