An ESP8266 Environmental Monitor In Your USB Port

January 8, 2020 by Tom Nardi 28 Comments

At this point, we’ve all seen enough ESP8266 “weather stations” to know the drill: you just put the ESP and a temperature sensor inside a 3D printed case, and let all those glorious Internet Points™ flow right on in. It’s a simple, and perhaps more importantly practical, project that seems to never get old. But that doesn’t mean there isn’t room for innovation.

Annoyed by the unnecessary bulk of existing solutions, [cperiod] has come up with an ESP8266 temperature and humidity sensor that can plug directly into a standard USB port. Slotted into a USB wall charger or power bank, this diminutive board can provide inconspicuous remote environmental monitoring wherever you need it. For extra hacker points, the board was even produced at home on a PCB mill.

In addition to the ESP-7 or 12 module (which plugs in via a header, should you need to swap it out), the board features a CH330N USB to UART chip and HT7233 voltage regulator. For the sensor itself, [cperiod] has bucked convention a bit and went with the I2C-connected AHT10 over something more common like a member of the BME family.

Unfortunately, this design suffers from the same issue we’ve seen in other compact environmental monitoring solutions; namely, that the heat generated by the chip itself skews the temperature readings. To combat this, aggressive power saving functions are baked into the firmware to make sure the ESP is in a deep sleep as much as possible. While not a perfect solution, it does prevent the ESP from warming the PCB up so much that it invalidades the reported data.

By now, the particularly astute reader may have realized that all the additional components used for the USB side of this board aren’t strictly necessary. After all, if you can pull the ESP module out of the header and program it separately, then you don’t actually need to include that capability in each sensor node. While true, we’re hardly the ones to complain when a hacker showboats a bit on their designs.

Breathe Easy With This Online Dust Sensor Box

December 27, 2019 by Tom Nardi 4 Comments

It’s an unfortunate reality that for many of us, our air isn’t nearly as clean as we’d like. From smog to wildfires, there’s a whole lot of stuff in the air that we’d just as soon like to keep out of our lungs. But in order to combat this enemy, you first need to understand it. That means figuring out just what’s in the air you breathe, and how much of it. That’s where devices like the Dust Box from [The IoT GURU] can come in handy.

Inside the 3D printed enclosure is a Wemos D1 Mini ESP8266 development board, sitting on a custom breakout PCB. This board gives you some easy expandability to add your own sensors and hardware, though in this particular configuration, the Dust Box is using the BME280 sensor for general environmental monitoring and the SDS011 laser particle sensor to determine what’s in the air. Just plug it into a convenient USB power source, make sure it’s connected to the WiFi, and off it goes.

But where does all that lovely data end up? That’s up to you, but in this case, the [The IoT GURU] is pushing everything out to a web interface that allows the user to view yearly, monthly, and weekly historical data for each of the parameters the Dust Box can check. This is probably a bit more granular than most of us need, but it’s a good example of what’s possible should you need that much information.

For a similar project that allows you to take your sensors a bit farther off the beaten path, checkout FieldKit, which was recently crowned winner of the 2019 Hackaday Prize.

Handheld MQTT Remote For Home Automation

December 26, 2019 by Tom Nardi 16 Comments

If you’re working on a home automation project, you’re probably knee-deep into MQTT by now. If not, you should be. The lightweight messaging protocol is an ideal choice for getting your “Things” on the Internet, and controlling them all can be done easily through a simple web interface or an application on your mobile device. Or if you’re [serverframework], you make yourself a handsome little all-in-one MQTT remote.

The hardware here is pretty simple; inside there’s just a NodeMCU ESP8266 development board, some buttons, an RGB LED to give feedback, and a 3.7v 1200mAh LiPo battery with associated charging module. Everything is held inside a nice little wooden box that looks like it would fit right in with the living room decor. We’d like to see some kind of a cover over the exposed perfboard the circuit is assembled on, but that’s arguably a personal preference kind of thing.

Most of the magic in this project is actually happening on the software side. Not only does the provided source code handle all the MQTT communications with Home Assistant, but it provides a clever user interface that allows [serverframework] to perform 25 functions with just five buttons. No, you aren’t seeing things. There are actually six buttons on the device, but one of them is a dedicated “power” button that wakes the remote out of deep sleep.

If you’d like to learn more about getting this protocol working for you, our resident MQTT guru [Elliot Williams] has plenty of thoughts on the subject. From his talk at the 2017 Hackaday Supercon to his home automation tutorial series, there’s plenty of information to get you started.

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Simple Pogo Programmer For ESP8266 Modules

December 7, 2019 by Tom Nardi 19 Comments

ESP8266 development boards like the Wemos D1 Mini and NodeMCU are an excellent way to get a one-off project up and rolling quickly, but their size and relative complexity mean they aren’t necessarily a good choice for even short-run production hardware. On the other hand, programming the bare ESP modules can be something of a pain. But thanks to [Greg Frost], flashing those tiny little boards just got a lot easier.

His 3D printed design uses pogo pins to securely connect to the board’s castellated edges, which also holds it in place during the programming process. On the back side there’s just a few jumper wires and a couple of resistors, which ultimately lead to the FT232R FTDI board that actually connects the chip to the computer so you can program it.

We’d like to see a back panel that encloses the wiring, and perhaps an alternate version that deletes the space for the FTDI board in favor of a row of header pins. Both easy enough modifications to the basic design should [Greg] or anyone else feel so inclined. But even as it is, this is a great little programmer that can be sourced and assembled easily and cheaply.

This isn’t the first 3D printed ESP8266 programmer we’ve seen, and there are some improvised versions which are even cheaper to put together, but this design has a certain professional look that we think will be right at home on your bench.

Zombies Ate Your Neighbors? Tell Everyone Through LoRa!

December 4, 2019 by Sven Gregori 24 Comments

As popular as the post-apocalyptic Zombie genre is, there is a quite unrealistic component to most of the stories. Well, apart from the whole “the undead roaming the Earth” thing. But where are the nerds, and where is all the apocalypse-proof, solar-powered tech? Or is it exactly this lack of tech in those stories that serves as incentive to build it in the first place? Well, maybe it doesn’t have to be the end of the world to seek for ways to cope with a collapse of our modern communication infrastructure either. Just think of natural disasters — an earthquake or hurricane causing a long-term power outage for example. The folks at [sudomesh] tackle exactly this concern with their fully open source, off-grid, solar-powered, LoRa mesh network, Disaster Radio.

The network itself is built from single nodes comprising of a battery-backed solar panel, a LoRa module, and either the ESP8266 or ESP32 for WiFi connectivity. The idea is to connect to the network with your mobile phone through WiFi, therefore eliminating any need for additional components to actually use the network, and have the nodes communicate with each other via LoRa. Admittedly, LoRa may not be your best choice for high data rates, but it is a good choice for long-range communication when cellular networks aren’t an option. And while you can built it all by yourself with everything available on [sudomesh]’s GitHub page, a TTGO ESP32 LoRa module will do as well.

If the idea itself sounds familiar, we did indeed cover similar projects like HELPER and Skrypt earlier this year, showing that LoRa really seems to be a popular go-to for off-grid communication. But well, whether we really care about modern communication and helping each other out when all hell breaks loose instead of just primevally defending our own lives is of course another question.

A Printed Case For Your ESP Environmental Sensors

November 28, 2019 by Tom Nardi 16 Comments

We’ve said it before but it’s worth repeating: rolling your own hardware solution is ridiculously easy these days. If you want to make a network attached environmental sensor, you wire a DHT11 up to an ESP8266 and you’re done. Time to move onto the software. In fact, it can take longer to come up with some kind of suitable enclosure for your hardware project than it does to assemble the thing.

Which is why [Pixel Hawk] has come up with this elegant 3D printed enclosure for the ESP8266 and ESP32. It’s designed to hold the microcontroller in the bottom compartment, while the environmental sensor (either the DHT11 or DHT22) is mounted to the top so it’s exposed to the outside. The case snap fits together so you don’t have to worry about gluing it, and there’s even an opening so you can keep the USB cable plugged in.

In the notes for the design, he mentions that in testing it was determined that the heat of the ESP itself can skew the temperature readings. So he recommends putting the microcontroller to sleep whenever possible, and keeping reads short so the enclosure doesn’t have time to heat up. He’s also created an alternate version of the case with more openings which should help combat this issue if you need to keep the chip awake.

If you’re looking for a complete solution, [Pixel Hawk] has included the source code he personally used to get his ESP32 sensor talking to Blynk, but you certainly don’t have to go that route if you don’t want to. There’s no shortage of existing projects out there that will help you get started with whole-house environmental monitoring. Our very own [Elliot Williams] happens to be partial to MQTT when he wants to get all his gadgets to play nice.

A Tiny Terminal For Your Serial Access Needs

November 22, 2019 by Jenny List 3 Comments

Some pieces of computing equipment have faded away without a trace, for example a modem is not a device that detains many hackers as they strive for that perfect emulation of a venerable Hayes on an Arduino. But there are some other devices that continue to hold a fascination, even years after they departed from the professional arena. A great example is the serial terminal. Once to be found on many a desk as it provided a way into a minicomputer, it has long ago been supplanted by terminal emulators or simply other portals into computing services such as the web. But in our community there are still plenty of serial terminals to be found, for example [RedHog]’s little emulated VT220 on an ESP8266 platform.

If you were hoping for a full-green screen and keyboard to plug into a hefty D-connector serial port then you’ll be a bit disappointed, as with a tiny screen and only a few buttons on a dev board or an Arduboy it’s not going to allow any 1337 vi mastery even with its on-screen keyboard. Take a look, we’ve placed a video below the break. But despite all that it shows promise, with ability to use either the logic-level serial port or the USB serial interface. We can see that it might find a use as a serial display though, but it would fascinate us to see what could be done were it to use the 8266’s on-board WiFi in some form. If you’d like to experiment you can do so with the code on GitHub.

This isn’t the first such terminal we’ve seen here before of course, some of them have been extremely practical, while others we just want to own because they’re cool.

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