Simple ESP8266 Weather Station Using Blynk

August 20, 2018 by Tom Nardi 11 Comments

Today’s hacker finds themself in a very interesting moment in time. The availability of powerful microcontrollers and standardized sensor modules is such that assembling the hardware for something like an Internet-connected environmental monitor is about as complex as building with LEGO. Hardware has become elementary in many cases, leaving software as the weak link. It’s easy to build the sensor node to collect the data, but how do you display it in a useful and appealing way?

This simple indoor temperature and humidity sensor put together by [Shyam Ravi] shows one possible solution to the problem using Blynk. In the video after the break, he first walks you through wiring the demonstration hardware, and then moves on to creating the Blynk interface. While it might not be the ideal solution for all applications, it does show you how quickly you can go from a handful of components on the bench to displaying useful data.

In addition to the NodeMCU board, [Shyam] adds a DHT11 sensor and SSD1306 OLED display. He’s provided a wiring diagram in the repository along with the Arduino code for the ESP8266, but the hardware side of this demonstration really isn’t that important. You could omit the OLED or switch over to something like a BME280 sensor if you wanted to. The real trick is in the software.

For readers who haven’t played with it before, Blynk is a service that allows you to create GUIs to interact with microcontrollers from anywhere in the world. The code provided by [Shyam] reads the humidity and temperature data from the DHT11 sensor, and “writes” it to the Blynk service. From within the application, you can then visualize that data in a number of ways using the simple drag-and-drop interface.

We’ve seen Blynk and ESP8266 used to control everything from mood lighting to clearance-rack robotic toys. It’s a powerful combination, and something to keep in mind next time you need to knock something together in short order.

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What’s Behind The Door? An IoT Light Switch

August 17, 2018 by Kristina Panos 33 Comments

We’re not sure who designed [Max Glenister]’s place, but they had some strange ideas about interior door positioning. The door to his office is right next to a corner, yet it opens into the room instead of toward the wall. Well, that issue’s been taken care of. But the architect and the electrician got the last laugh, because now the light switch is blocked by the open door.

Folks, this is the stuff that IoT is made for. [Max] here solved one problem, and another sprang up in its place. What better reason for your maiden voyage into the cloud than a terrible inconvenience? He studied up on IoT servo-controlled light switching, but found that most of the precedent deals with protruding American switches rather than the rockers that light up the UK. [Max] got what he needed, though. Now he controls the light with a simple software slider on his phone. It uses the Blynk platform to send servo rotation commands to a NodeMCU, which moves the servo horn enough to work the switch. It’s simple, non-intrusive, and it doesn’t involve messing with mains electricity.

His plan was to design a new light switch cover with mounting brackets for the board and servo that screws into the existing holes. That worked out pretty well, but the weight of the beefy servo forced [Max] to use a bit of Gorilla tape for support. He’s currently dreaming up ways to make the next version easily detachable.

Got those protruding American switches? [Suyash] shed light on that problem a while back.

Track Everything, Everywhere With An IoT Barcode Scanner

August 15, 2018 by Sean Boyce 33 Comments

I’ve always considered barcodes to be one of those invisible innovations that profoundly changed the world. What we might recognize as modern barcodes were originally designed as a labor-saving device in the rail and retail industries, but were quickly adopted by factories for automation, hospitals to help prevent medication errors, and a wide variety of other industries to track the movements of goods.

Medication errors in hospitals are serious and scary: enter the humble barcode to save lives. Source: The State and Trends of Barcode, RFID, Biometric and Pharmacy Automation Technologies in US Hospitals

The technology is accessible, since all you really need is a printer to make barcodes. If you’re already printing packaging for a product, it only costs you ink, or perhaps a small sticker. Barcodes are so ubiquitous that we’ve ceased noticing them; as an experiment I took a moment to count all of them on my (cluttered) desk – I found 43 and probably didn’t find them all.

Despite that, I’ve only used them in exactly one project: a consultant and friend of mine asked me to build a reference database out of his fairly extensive library. I had a tablet with a camera in 2011, and used it to scan the ISBN barcodes to a list. That list was used to get the information needed to automatically enter the reference to a simple database, all I had to do was quickly verify that it was correct.

While this saved me a lot of time, I learned that using tablet or smartphone cameras to scan barcodes was actually very cumbersome when you have a lot of them to process. And so I looked into what it takes to hack together a robust barcode system without breaking the bank.

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Internet Of Tea: Coaster Watches For Optimum Drinking Temperature

August 14, 2018 by Dan Maloney 3 Comments

Ah, the age-old question: at what temperature does one’s tea need to be for maximum enjoyment? It’s subjective, of course, but subjective in a way that makes everyone else’s opinion demonstrably wrong. What’s worse, the window of opportunity for optimum tea temperature is extremely narrow. What’s a tea drinker to do?

Throw a little technology at the problem, of course, in the form of this Internet of Tea smart coaster. Through careful experimentation, [Benjojo] determined the temperature of his favorite mug when the tea within was just right for drinking and designed a coaster to alert him to that fact. The coaster is 3D-printed and contains an MLX90616 IR temperature sensor looking up at the bottom of the mug. An ESP8266 lives inside the coaster too and watches for the Optimum Tea Window to open, sending an alert via Discord when the time is right. Yes, he admits that a simple blinking LED on the coaster would keep his tea habit metadata from being slurped up by the international tea intelligence community, but he claims he has nothing to hide. Good luck with that.

What’s next for [Dane]’s tea preparation? Perhaps he can close the loop and automate the whole pre-consumption process.

Programmable Badge Uses E-Ink And ESP8266

August 8, 2018 by Tom Nardi 34 Comments

You’ve probably noticed that the hacker world is somewhat enamored with overly complex electronic event badges. Somewhere along the line, we went from using a piece of laminated paper on a lanyard to custom designed gadgets that pack in enough hardware that they could have passed for PDAs not that long ago. But what if there was a way to combine this love for weighing down one’s neck with silicon jewelry and the old school “Hello my name is…” stickers?

[Squaro Engineering] might have the solution with Badgy, their multi-function e-ink name…well, badge. Compatible with the Arduino SDK, it can serve as anything from a weather display to a remote for your smart home. Oh, and we suppose in an absolute emergency it could be used to avoid having to awkwardly introduce yourself to strangers.

Powered by an ESP-12F, Badgy features a 2.9″ 296×128 E-Ink display and a five-way tactical switch for user input. The default firmware includes support for WiFiManager and OTA updates to make uploading your own binaries as easy as possible, and a number of example Sketches are provided to show you the ropes. Powered by a LIR2450 3.6 V lithium-ion rechargeable coin cell, it can run for up to 35 days in deep sleep or around 5 hours of heavy usage.

Schematics, source code, and a Bill of Materials are all available under the MIT license if you want to try your hand at building your own, and assembled badges are available on Tindie. While it might not be as impressive as a retro computer hanging around your neck, it definitely looks like an interesting platform to hack on.

Why Have Only One Radio, When You Can Have Two?

July 28, 2018 by Jenny List 4 Comments

There are a multitude of radio shields for the Arduino and similar platforms, but they so often only support one protocol, manufacturer, or frequency band. [Jan Gromeš] was vexed by this in a project he saw, so decided to create a shield capable of supporting multiple different types. And because more is so often better, he also gave it space for not one, but two different radio modules. He calls the resulting Swiss Army Knife of Arduino radio shields the Kite, and he’s shared everything needed for one on a hackaday.io page and a GitHub repository.

Supported so far are ESP8266 modules, HC-05 Bluetooth modules, RFM69 FSK/OOK modules, SX127x series LoRa modules including SX1272, SX1276 and SX1278, XBee modules (S2B), and he claims that more are in development. Since some of those operate in very similar frequency bands it would be interesting to note whether any adverse effects come from their use in close proximity. We suspect there won’t be because the protocols involved are designed to be resilient, but there is nothing like a real-world example to prove it.

This project is unique, so we’re struggling to find previous Hackaday features of analogous ones. We have however looked at an overview of choosing the right wireless tech.

ESP8266 Internet Controlled LED Dimmer

July 27, 2018 by Tom Nardi 11 Comments

There’s no shortage of debate about the “Internet of Things”, largely centered on security and questions about how much anyone really needs to be able to turn on their porch light from the other side of the planet. But while many of us are still wrestling with the realistic application of IoT gadgets, there’s undoubtedly those among us who have found ways to put this technology to work for them.

One such IoT devotee is [Sasa Karanovic], who writes in to tell us about his very impressive custom IoT LED dimmer based on the ESP8266. Rather than rely on a commercial lighting controller, he’s designed his own hardware and software to meet his specific needs. With the LED strips now controllable by any device on his network, he’s started working on Python scripts which can detect what he’s doing on his computer and react accordingly. For example, if he’s watching a movie the lights will automatically dim, and come back up when he’s done.

[Sasa] has provided all the files necessary to follow in his footsteps, from the Gerber files for his PCB to the Arduino code he’s running on the ESP. The source code is especially worth checking out, as he’s worked in a lot of niceties that we don’t always see with DIY projects. From making sure the ESP8266 gets a resolvable DNS hostname on the network to using websockets which update all connected clients with status info in real-time, he’s really put a lot of work into making the experience as complete as possible.

He’s explains in his blog post what needs to be edited to put this code to work in your own environment, and there’s even some descriptive comments in the code and a helpful debug mode so you can see how everything works. It’s always a good idea to consider that somebody else down the road might be using your code; taking a few minutes to make things clear can save them hours of stumbling around in the dark.

If you need more inspiration for your ESP8266 lighting project, check out this ambient lighting controller for a kid’s room, or this professional under-cabinet lighting controller.