Give Your Smart Home A Green Thumb With MQTT

March 7, 2021 by Michael Shaub 36 Comments

We have all been stuck inside for too long, and maybe that’s why we have recently seen a number of projects attempting to help humans take better care of their housemates from Kingdom Plantae. To survive, plants need nutrients, light, and water. That last one seems tricky to get right; not too dry and not drowning them either, so [rbaron’s] green solder-masked w-parasite wireless soil monitor turns this responsibility over to your existing home automation system.

Like this low-power soil sensor project and the custom controller for six soil sensors, [rbaron’s] w-parasite uses a “parasitic capacitive” moisture sensor to determine if it’s time to water plants. This means that unlike resistive soil moisture sensors, here the copper traces are protected from corrosion by the solder mask. For those wondering how they work, [rbaron]’s Twitter thread has a great explanation.

The “w” in the name is for WiFi as the built-in ESP-32 module then takes the moisture reading and sends an update wirelessly via MQTT. Depending on the IQ of your smart-home setup, you could log the data, route an alert to a cellphone, light up a smart-bulb, or even switch on an irrigation system.

[rbaron] has shared a string of wireless hacks, controlling the A/C over Slack and a BLE Fitness Tracker that inspired more soldering than jogging. We like how streamlined this solution is, with the sensor, ESP-32 module, and battery all in a compact single board design. Are you asking yourself, “but how is a power-hungry ESP-32 going to last longer than it takes for my geraniums to dry out?” [rbaron] is using deep sleep that only consumes 15uA between very quick 500ms check-ins. The rechargeable LIR2450 Li-Ion coin cell shown here can transmit a reading every half hour for 90 days. If you need something that lasts longer than that, use [rbaron]’s handy spreadsheet to choose larger batteries that last a whole year. Though, let’s hope we don’t have to spend another whole year inside with our plant friends.

We may never know why the weeds in the cracks of city streets do better than our houseplants, but hopefully, we can keep our green roommates alive (slightly longer) with a little digital nudge.

The Latest, Best WiFi Module Has Been Announced

November 6, 2015 by Brian Benchoff 85 Comments

A little more than a year ago, a new product was released onto the vast, vast marketplace of cheap electronics. It was the ESP8266, and this tiny and cheap WiFi module has since taken over the space of hobbyist electronics and become the de facto standard for connecting tiny microcontrollers to the Internet.

Now there’s an upgrade on the horizon. [John Lee], the public face of Espressif, the makers of the ESP8266, has announced the next product they’re working on. It’s called the ESP32, and if the specs given are correct, it looks to be the next great thing for the Internet of Things.

The ESP32 will now contain two Tensilica processors running at 160MHz, compared to the ‘8266’s one processor running at 80 MHz. The amount of RAM has been increased to 400 kB, Bluetooth LE has been added, WiFi is faster, and there are even more peripherals tucked away in this tiny piece of silicon.

The new ESP32 includes new, simplified APIs and unlike when the ESP8266 was announced, documentation in English.

Right now, Espressif is beta testing the ESP32, with about 200 boards manufactured so far. If you’re one of the few lucky people who have one of these boards on your workbench, we’d love to see your take on it.

New Part Day: The ESP8266 Killer

July 13, 2015 by Brian Benchoff 183 Comments

Around this time last year we first heard of the ESP8266 WiFi module. It’s still a great little module, providing WiFi connectivity for all those Internet of Things things at a price point of just $5. It’s an attractive price for a great module with a huge community pumping out a lot of projects for the platform.

Now there’s a new kid on the block. It’s called the EMW3165, and like the ESP it provides WiFi connectivity for a bunch of wireless projects. It’s much, much more capable with an STM32F4 ARM Coretex M4 microcontroller, a ‘self hosted’ networking library, more RAM, more Flash, and more GPIOs. How much, you’re probably asking yourself. It’s a dollar more than the ESP8266.

The datasheet for the module goes over all the gritty details. While this chip has 3.6V I/Os, there are some 5V tolerant pins – a boon for the Arduino crowd. It’s also surprisingly low power for something that connects to an 802.11n network. The real bonus here is the STM32F4 core – that’s a very, very powerful microcontroller, and if you want a 2-component WiFi webcam build, this is the part you should use. There will be a lot of interesting builds using this part. It’s also passed FCC certification. Very cool.

ESP Gets FCC And CE

December 17, 2014 by Brian Benchoff 58 Comments

The ESP8266 Internet of Things module is the latest and greatest thing to come out of China. It’s ideal for turning plastic Minecraft blocks into Minecraft servers, making your toilet tweet, or for some bizarre home automation scheme. This WiFi module is not, however, certified by the FCC. The chipset, on the other hand, is.

Having a single module that’s able to run code, act as a UART to WiFi transceiver, peek and poke a few GPIOs, all priced at about $4 is a game changer, and all your favorite silicon companies are freaking out wondering how they’re going to beat the ESP8266. Now the chipset is FCC certified, the first step to turning these modules into products.

This announcement does come with a few caveats: the chipset is certified, not the module. Each version of the module must be certified by itself, and there are versions that will never be certified by the FCC. Right now, we’re looking at the ESP8266-06, -07, -08, and -12 modules – the ones with a metal shield – as being the only ones that could potentially pass an FCC cert. Yes, those modules already have an FCC logo on them, but you’re looking at something sold for under $5 in China, here.

Anyone wanting to build a product with the ESP will, of course, also need to certify it with the FCC. This announcement hasn’t broken down any walls, but it has cracked a window.

The ESP8266 Becomes A Terrible Browser

October 4, 2014 by Brian Benchoff 11 Comments

The ESP8266 are making their way over from China and onto the benches of tinkerers around the world for astonishing web-enabled blinking LED projects and the like. [TM] thought he could do something cooler with his WiFi to UART module and decided to turn one into a web browser.

There’s no new code running on the ESP8266 – all the HTML is being pushed through an Arduino Mega, requesting data from a server (in this case our fabulous retro edition), and sending the data to the Arduino serial console. The connection is first initiated with a few AT commands to the ESP module, then connecting to the retro server and finally dumping everything received to the console.

It’s not much – HTML tags are still displayed, and images are of course out of the question. The result, however, isn’t that much different from what you would get from Lynx, meaning now the challenge is open for an Arduino port of this ancient browser.

More WiFi Modules For IoT Madness

September 7, 2014 by Brian Benchoff 33 Comments

The last year has brought us CC3000 WiFi module from TI, and recently the improved CC3200 that includes an integrated microcontroller. The Chinese design houses have gotten the hint, putting out the exceptionally cheap ESP8266, a serial to WiFi bridge that also includes a microcontroller to handle the TCP/IP stack and the software side of an 802.11 connection. Now there’s another dedicated WiFi module. It’s called the MT7681, and it’s exactly what you would expect given the competition: a programmable module with the ability to connect to a WiFi network.

Like TI’s CC3200, and the ESP8266, the MT7681 can be connected to any microcontroller over a serial connection, making it a serial to WiFi bridge. This module also contains a user-programmable microcontroller, meaning you don’t need to connect an Arduino to blink a few pins; UART, SPI, and a few GPIO pins are right on the board. The module also includes an SDK and gnu compiler, so development of custom code running on this module should be easier than some of the other alternatives.

You can pick up one of the MT7681 modules through the usual channels, but there’s an Indiegogo campaign based in China that takes this module and builds a ‘dock’ around it. The dock has a relay, temperature/humidity sensor, a few GPIO pins, and a USB serial connection for use as an Internet of Things base station.

For anyone looking for a little more computational horsepower, there’s also a few mentions and press releases announcing another module, the MT7688, This is a very small (12mm by 12mm) module running Linux with 256 MB of RAM and 802.11n support. This module hasn’t even hit the market yet, but we’ll be on the lookout for when it will be released.

Thanks [uhrheber] for sending this one in.

New Chip Alert: The ESP8266 WiFi Module (It’s $5)

August 26, 2014 by Brian Benchoff 145 Comments

Every so often we run across something in the Hackaday tip line that sends us scurrying to Google, trying to source a component, part, or assembly. The ESP8266 WiFi module is the latest, made interesting because it pretty much doesn’t exist outside China.

Why is it cool? It’s a WiFi module with an SOC, making it somewhat similar to TI’s CC300 in conception (A.K.A. the thing that makes the Spark Core so appealing), in that a microcontroller on the module takes care of all the WiFi, TCP/IP stack, and the overhead found in an 802.11 network. It’s addressable over SPI and UART, making this an exceptionally easy choice for anyone wanting to build an Internet of Things thing; you can simply connect any microcontroller to this module and start pushing data up to the Internet. Oh, it’s also being sold for $5 in quantity one. Yes, for five dollars you can blink a LED from the Internet. That’s about half the price as the CC3000 itself, and a quarter of the price if you were to build a CC3000 breakout board.

There’s a catch, right, there’s always a catch. Yep. About two hours after this post is published it will be the number one English language Google result for “ESP8266.” As far as the English-speaking world is concerned, there is absolutely nothing to be found anywhere on the Internet on this module.

Seeed Studio recently sold a few of these modules for $7 and has some documentation, including a full datasheet and an AT command set. All the documentation is in Chinese. There’s also an “ESP8266 IoT SDK”, but from a quick glance at the code, this appears to be an SDK for the SOC on the module, not a simple way to connect the module to a microcontroller.

Anyone wanting to grab one of these modules can do so on Ali Express. Anyone wanting to do something with one of these modules will have a much more difficult time, most likely poking and prodding bits randomly with the help of Google translate. Should someone, or even a group of people, want to take up the task of creating a translation of the datasheet and possibly a library, we have a pretty collaborative project hosting site where you can do that. You may organize in the comments below; we’ll also be taking bets as to when a product using the ESP8266 will be found on Kickstarter. My guess is under a month.

EDIT: Here’s a translation of the datasheet and AT command set.

Edit two: [bafeigum] is writing a library go help him out.

Thanks [Liam] for the tip.