Hackaday Prize Entry: Thingspeak IoT Heart Rate Monitor

[Naman Chauhan]’s 2017 Hackaday Prize entry consists of a heartbeat detection and monitoring system that centers around everyone’s favorite WiFi board, the ESP8266. The monitor is hooked up to the patient’s finger, keeping track of his or her vitals and publishing the data on the cloud.

By using Thingspeak to manage the data, [Naman] leverages the platform’s data visualization and analytical features. Also, by making the data accessible on the cloud, he offers an intriguing opportunity to help friends and relatives to monitor the data. If you think about it, if you had a loved one in the hospital, wouldn’t having all of his or her chart available on your phone be great?

Reverse Polish Notation And Its Mildly Confusing Elegance

The best rummage sale purchase I ever made was a piece of hardware that used Reverse Polish Notation. I know what you’re thinking… RPN sounds like a sales gimmick and I got taken for a fool. But I assure you it’s not only real, but a true gem in the evolution of computing.

Best rummage sale find ever!
Best rummage sale find ever!

Sometime in the 1980s when I was a spotty teen, I picked up a calculator at a rummage sale. Protected by a smart plastic case, it was a pretty good condition Sinclair Scientific that turned out when I got it home to have 1975 date codes on its chips, and since anything with a Sinclair badge was worth having it became mine for a trifling amount of money. It had a set of corroded batteries that had damaged one of its terminals, but with the application of a bit of copper strip I had a working calculator.

And what a calculator! It didn’t have many buttons at a time when you judged how cool a scientific calculator was by the prolific nature of its keyboard. This one looked more akin to a run-of-the-mill arithmetic calculator, but had button modes for trigonometric functions and oddly an enter key rather than an equals sign. The handy sticker inside the case explained the mystery, this machine used so-called Reverse Polish Notation, or RPN. It spent several years on my bench before being reverently placed in a storage box of Sinclair curios which I’ve spent half a day turning the house over to find as I write this article.

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Hackaday Superconference Kicks Off With A Party

Begin the Hackaday Superconference a day early this year. Supercon is far more than a conference, it’s a Hacker Village that forms when we all get together and that’s happening on Friday, November 10th with early badge hacking, dinner, and a party all included with your Supercon ticket!

In the last year, Supplyframe (Hackaday’s parent company) moved into a new office. It’s a beautiful space with enough square footage to host a conference itself. This year we’ll be capitalizing on that by hosting some of the larger Superconference workshops there. They’ve also opened their doors and are pulling out all the stops for the meet-and-greet pregame on Friday. Just let us know you’ll be there.

Badge pick up and hacking will begin at noon. If you’re itching to get your hands on the amazing Supercon badge, this is where you want to be. As we move into the five o’clock hour we’ll bring in the catering and the bartenders for a bash that welcomes back your extended family of hackers, designers, and engineers. This an amazing community and you’re a part of it so make your plans to get to town early.

Is a day early not good enough for you? You’re in luck! We’ve opened up a chat room on Hackaday.io. Talk to one another about what to bring, how to get there, what to do, and who exactly already has the Gerbers for the Superconference badge. It’s going to be a fantastic conference, and we can’t wait to see you there!

Heavily Hacked Printer For DIY PCBs

Sometimes we get tips that only leave us guessing as to how — and sometimes why — a project was built. Such is the case with this PCB printer; in this case, the build specifics are the only thing in question, because it puts out some pretty impressive PCBs.

All we have to go on is the video after the break, which despite an exhaustive minutes-long search appears to be the only documentation [Androkavo] did for this build. The captions tell us that the printer is built around the guts from an Epson Stylus Photo 1390 printer. There’s no evidence of that from the outside, as every bit of the printer has been built into a custom enclosure. The paper handling gear has been replaced by an A3-sized heated flatbed, adjustable in the Z-axis to accommodate varying board thicknesses. The bed runs on linear rails that appear custom-made. Under the hood, the ink cartridges have been replaced with outboard ink bottles in any color you want as long as it’s black. The video shows some test prints down to 0.1 mm traces with 0.1 mm pitch — those were a little dodgy, but at a 0.2 mm pitch, the finest traces came out great. The boards were etched in the usual way with great results; we wonder if the printer could be modified to print resist and silkscreens too.

[Androkavo] seems to have quite a few interesting projects in his YouTube channel, one of which — this wooden digital clock — we featured recently. We’d love to learn more about this printer build, though. Hopefully [Androkavo] will see this and comment below.

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Rosalind Franklin Saw DNA First

It’s a standard science trivia question: Who discovered the structure of DNA? With the basic concepts of molecular biology now taught at a fairly detailed level in grade school, and with DNA being so easy to isolate that it makes a good demonstration project for school or home, everyone knows the names of Watson and Crick. But not many people know the story behind one of the greatest scientific achievements of the 20th century, or the name of the scientist without whose data Watson and Crick were working blind: Rosalind Franklin.

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Portable Pi And Fresh Breath

There’s a long history of building things in Altoid tins, but the Pi-Tac 1.0 uses a Pi Zero W inside a Tic-Tac box. In addition to the processors, there is a tiny OLED display and a battery controller. According to a Reddit post, [Deathonater] plans to use it as a WiFi access point.

The display and the battery/power controller are from AdaFruit. You can find some sample code for the battery controller if you want to duplicate the design. You can also opt for an enhanced version that can report the battery state readily.

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Tiny, Wearable 8-Bit VT100 Terminal

In the modern era of computing, the end-user is often quite far removed from the machine they’re using. At least in terms of abstraction levels, the user experience of most computers, smart phones, and the like are very far away from the zeros and ones. If you need to get down to that level though, you’ll have to make your way to a terminal somehow, and reminisce fondly about the days when everything was accessed through a serial line.

Nowadays, some harmless nostalgia is often accompanied by a challenge as well, as [Nick] demonstrated with his tiny serial terminal. It mimics the parsing and rendering of a VT100 console using an Arduino Uno and a 1″x1″ TFT screen. His goal was to make it wearable like a wristwatch would be, using two buttons as an HID device. With the size and simple interface, [Nick] also explores the possibility of mounting such a terminal to a pair of glasses.

While not everyone may want to interact with a serial terminal with only two buttons, it’s certainly a great demonstration of what is possible when it comes to implementing retro software in unique ways. There have been serial terminals implemented in many other unique places as well, such as old oscilloscopes and replicas from popular video games.