Building An Army Of ESP32 Air Quality Sensors

April 5, 2019 by Tom Nardi 20 Comments

The ESP8266 and its heavyweight sibling the ESP32 are fantastic boards to develop with as they allow you to quickly and easily get a project online. Just tack a few sensors and some LEDs on them, and you’re well on the way to producing your own “Internet of Things”. The real challenge is utilizing the incredible capabilities these boards offer us to do something meaningful.

Judging by what he’s got so far, we think [Samuel Klit] is well on his way. He’s using the ESP32 and some off-the-shelf modular components to create an Internet-connected air quality monitoring station. But he’s not just building one or two of them, he’s building enough so they can be distributed and collect data over a wide area. Who knows, perhaps you’ll be building one next.

[Samuel] is using the CCS811 sensor which can pick up potentially harmful Volatile Organic Compounds (VOCs) and determine carbon dioxide concentrations, as well as a BMP280 sensor to read ambient temperature and atmospheric pressure. There’s also an SD card reader for local data storage, a 1602 LCD display that provides a basic user interface, and the electronics required to support the 18650 Li-Ion batteries which power the unit for up to 12 hours on a charge. Everything’s held in a professional looking enclosure that we’ll be sure to add to our next AliExpress order.

Collecting data is one thing, but what do you do with it once you’ve got it? To that end, each node runs a web interface that not only allows you to view current hardware status and download the locally stored data, but also provides an easy to understand visual representation of the environmental conditions. To get around the limited storage space for web assets on the chip, [Samuel] is calling out to Chart.js to inject some slick graphics into the web interface on-demand. The web interface is a particularly nice touch, and an excellent use of the power and capabilities offered by the ESP32.

We’ve previously seen air quality sensors added to Taxi cabs in Peru, the homes surrounding Barcelona’s Plaza del Sol, and of course [Radu Motisan] has done incredible work towards the goal of creating city-wide environmental monitoring networks. With increasingly capable technologies, it looks like citizens are studying the world around them in greater numbers than ever before.

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ESP32 Video Tricks Hack Chat With Bitluni

March 25, 2019 by Dan Maloney 2 Comments

Join us Wednesday at noon Pacific time for the ESP32 Video Tricks Hack Chat!

The projects that bitluni works on have made quite a few appearances on these pages over the last couple of years. Aside from what may or may not have been a street legal electric scooter, most of them have centered around making ESP32s do interesting tricks in the analog world. He’s leveraged the DACs on the chip to create an AM radio transmitter, turned an oscilloscope into a video monitor, and output composite video. That last one was handy for turning a Sony Watchman into a retro game console. He’s also found ways for the ESP32 to output VGA signals. Looks like there’s no end to what he can make the versatile microcontroller do.

Although the conversation could (and probably will) go anywhere, we’ll start with video tricks for the ESP32 and see where it goes from there. Possible topics include:

Tricks for pushing the ESP32 DACs to their limits;
When to use an external DAC;
Optimizing ESP32 code by running on separate cores; and
What about HDMI on the ESP32?

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the ESP32 Video Tricks Hack Chat and we’ll put that in the queue for the Hack Chat discussion.

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, March 27, at noon, Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Hackaday Links: March 24, 2019

March 24, 2019 by Brian Benchoff 31 Comments

It has come to my attention that a few of you don’t know about Crystalfontz, an online store where you can find displays of all types, from USB LCD displays to I2C OLEDs, to ePaper displays. Thanks to [arthurptj] for that tip. Yes, Crystalfontz is cool, but have you ever heard of Panelook? Oh boy are there some displays at Panelook. Here’s a 1024 by 768 resolution display that’s less than half an inch across.

The comments section of Hackaday has been pretty tame as of late, so here’s why Apple is the king of design. It’s a question of fillets. There are a few ways to add a fillet to the corner of an icon or a MacBook. The first is to draw two perpendicular lines, then add a fixed radius corner. The Apple way is to make everything a squircle. The ‘squircle’ way of design is that there are no sudden jumps in curvature, and yes, you can do this in Fusion360 or any other design tool. This is also one of those things you can’t unsee once you know about it, like the arrow in the FedEx logo.

The ESP8266 simply appeared one day, and it changed everything. The ESP32, likewise, also just arrived on the Internet one day, and right now it’s the best solution for a microcontroller, with WiFi, that also does things really fast. Someone over at Espressif is dropping hints of a new microcontroller, with a possible release on April 1st (the same date that Apple released their competitor to the Raspberry Pi). Is it RISC-V? Is it 5V tolerant? Who knows! (Editor’s note: it’s not RISC-V. Though they’re saying that’s in the pipeline.)

The Verge got their hands on an original iPhone engineering validation unit. It’s a breakout board for an iPhone.

San Dimas High School Football Rules

There’s a screwdriver in your toolbox that has a cast clear handle, a blue ferrule surrounding the shaft, and red and white lettering on the side. Go check, it’s there. It’s a Craftsman screwdriver. It’s an iconic piece of design that’s so ubiquitous that it’s unnoticeable. It’s just what a screwdriver is. It’s a prototypical screwdriver. Thanks to the rise of resin and turning craftsmanship, there’s now a gigantic version of this screwdriver.

[The 8-Bit Guy] posted the following message on his Facebook on March 19th: “Just FYI – somebody hacked and totally erased my website. So, it’s going to be down for a while.” At the time of this writing, everything looks okay, which brings up the larger question of why Facebook is still a thing. We’re on a gradient of coolness here, and the sooner you delete your Facebook, the cooler you are. I, for example, deleted my Facebook during the Bush administration, and we all know how cool I am. I’ll never get to the singularity of coolness of kids who never had a Facebook in the first place, but the point remains: delete your Facebook old man.

[SirEdmar] wants to bring Fusion 360 to Linux users. Autodesk wants the same, and they tried a web-based version of Fusion 360, but… it’s a web version of Fusion 360. Right now the best solution is Wine, and thanks to [SirEdamr] 360 works in Wine.

Bing translate does Klingon! How well does it work? Not bad, it could use some work, mostly with non-standard vocabulary:

Hacker Abroad: Visiting Espressif And Surprising Subway Ads

March 22, 2019 by Mike Szczys 17 Comments

Thursday was my final day in Shanghai. After spending all of Wednesday at Electronica Asia, I headed over to the Espressif Headquarters which is just one subway stop away. This is of course the company behind the well-known ESP8266 and its younger sibling, the ESP32. My host was Ivan Grotkothov, Director of Software Platforms. The backstory on how he found his way to the company is truly interesting, as are the stories he shared on some of the legend and lore surrounding the WiFi capable chips the company makes — and the new one whose existence just leaked out this week.

Join me below for that and few other fun things from my last day in this city of 26 million people.

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Library Makes ESP Over The Air Updates Easy

March 21, 2019 by Al Williams 19 Comments

Potentially, one of the great things about having a device connected to the network is that you can update it remotely. However, how do you make that happen? If you use the Arduino setup for the ESP8266 or ESP32, you might try [scottchiefbaker’s] library which promises to make the process easy.

Adding it looks to be simple. You’ll need an include, of course. If you don’t mind using port 8080 and the path /webota, you only need to call handle_webota() from your main loop. If you want to change the defaults, you’ll need to add an extra call in your setup. You also need to set up a few global variables to specify your network parameters.

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Mining Bitcoin On The ESP32 For Fun, Definitely Not Profit

March 19, 2019 by Lewin Day 7 Comments

Bitcoin’s great, if you sold at the end of 2017. If you’re still holding, your opinion might be a little more sour. The cost to compete in the great hashing race continues to rise while cryptocurrency values remain underwhelming. While getting involved at the top end is prohibitively expensive, you can still have some fun with the basic concepts – as [Jake] did, by calculating Bitcoin hashes on the ESP32.

It’s a project that is very much done for fun, rather than profit. [Jake] notes that even maxing out both cores, it would take 31 billion years to mine one block at current difficulty levels. Regardless, the underlying maths is nothing too crazy. Double-hashing the right data with the SHA256 algorithm is all that’s required, a task that is well within the ESP32’s capabilities. There’s hardware acceleration available, too – though this is weirdly slower than doing it in software.

Overall, you’re not going to get rich hashing Bitcoin on a cheap microcontroller platform. You might just learn something useful, though. If this isn’t weird enough though, you could always try the same thing on a 1970s Xerox Alto.

RemoteDebug For ESP Platforms

March 7, 2019 by Lewin Day 10 Comments

Debugging tools are critical to quick and effective development. Without being able to peek under the hood at what’s really going on, it can be difficult to understand and solve problems. Those who live on the Arduino platform are probably well acquainted with using the serial port to debug, but it’s far from the only way. [JoaoLopesF] has coded the RemoteDebug tool for ESP platforms, and the results are impressive.

RemoteDebug does away with the serial interface entirely, instead using the ESP’s native wireless interface to send debug data over TCP/IP. It’s all handled over telnet, making it completely platform agnostic. By handling things over the WiFi connection, it negates issues with physical access, as well as hassles with cables and limited serial ports. It’s also of benefit to robotics projects, which no longer need a tether when debugging.

It comes with a similar set of features to [JoaoLopesF]’s earlier work, SerialDebug. Things like verbosity and timestamps are all built in, making it easy to get high-quality debug data without having to reinvent the wheel yourself. Video after the break.

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