Your Laundry Is Done!

August 1, 2016 by Jenny List 20 Comments

Have you ever put a load of dirty clothing in the washing machine and set the cycle running, only to forget all about it and discover a mouldering congealed mass in the machine a few days later? [Xose Pérez] has more than once, and to stop it happening again he’s got a project that monitors the machine in his basement and notifies him when his wash is done.

At the centre of his washing machine monitor is an ITead Sonoff IoT mains on-off switch. This device contains a 10A mains relay, an ESP8266 chip to control it, and a small mains switch-mode power supply. The Sonoff doesn’t use the ESP’s ADC pins, so he’s broken one of them out on a lead to a current transformer which captures the power level being consumed by the washing machine. The Sonoff is one of those IoT devices that relies on a proprietary cloud service and doesn’t have its own API, so [Xose] has created his own firmware for it incorporating an ESP port of an Arduino current sensing library. To round off the project and because he could, he’s added an ambient humidity sensor to the device.

The resulting boxed-up unit returns minute-by-minute current readings for the entire wash cycle. To spot when the cycle has finished, he waits for a moment when it has been using no power for more than five minutes, at which point his Node-RED system sends him a notification via Pushover.

This project is a very neatly executed hack on an extremely cheap piece of hardware whose capabilities would ordinarily be somewhat curtailed due to its proprietary interface. Surprisingly it’s not the first laundry monitor we’ve seen here at Hackaday, we’ve had this apartment laundry monitor using an accelerometer and a Raspberry Pi, and a notifier for a finicky dryer that insisted on stopping mid-cycle.

ESP8266 MicroPython Contest Gives You The Excuse You Need

July 29, 2016 by Elliot Williams 3 Comments

As if the prospect of having everyone’s favorite scripting language ported over weren’t enough to get you to install MicroPython on a spare ESP8266, there is now a contest for that. Over on Hackaday.io the MicroPython on ESP8266 contest is under way and you’ve only got until the end of August to submit your creation.

The prizes? First place gets an OpenMV camera board because [Radomir], who’s running the contest, has an extra one. OK, it’s not as lush as the corporate-sponsored goody-bag that we’ve got running in the Hackaday Prize, but there’s no reason that you can’t enter both. And if anyone wants to throw some more goodies into the pot, I’m sure they’d be welcome.

The rules are simple: use an ESP8266 or ESP8285 with MicroPython and post the project up on Hackaday.io. Bonus points are given for creating new libraries or hardware drivers. Basically, this just gives you an extra reason to get in there and play around. How cool is that?

If you need a start-up on MicroPython on the ESP8266, the official tutorial is great. We wrote up a first-look review of running MicroPython on the WeMos D1 hardware, but were plagued with (re-)flashing difficulties, so we’re going to have to give it another go.

New Chip Alert: RTL8710, A Cheaper ESP8266 Competitor

July 28, 2016 by Brian Benchoff 98 Comments

Almost exactly two years ago, shocking news thundered across the electronics blogosphere. There was a new WiFi module on the block. It was called the ESP8266, a simple serial device capable of taking care of an 802.11 network and a WiFi stack, giving any project with a microcontroller access to the Internet. Earlier modules to connect microcontrollers were sufficient for the task, but nothing could beat the ESP8266 on price.

Now, there’s a new module that’s even cheaper and more powerful than the ESP8266, and just like all of our favorite parts from China, it inexplicably shows up on eBay and AliExpress before anywhere else. It’s the Realtek RTL8710, available on eBay, on AliExpress, and elsewhere around the web for about $1.50 per device. There’s also a dev kit for the device featuring breakouts, an additional microcontroller, and a few switches and buttons for about $15.

As you would expect, there is zero English-language data available about the RTL8710, everything is in Chinese. There is a forum of sorts going over this new chip, and the Google Translatrix is good enough to glean a little bit of info about the new chip.

The RTL8710 features an ARM processor clocked at 166MHz. Stock, this module is running FreeRTOS. There’s 1MB of Flash, 48k of RAM available to the user, up to 21 GPIOs, 3 I2C, 4 PWM pins, and 2 PCM. This module also comes with an FCC logo, but I can’t find anything on the FCC website about this module.

If anything, the Realtek RTL8710 isn’t meant to be a competitor to the ESP8266. While extremely popular and still very useful, the ‘next gen’ ESP32 is due to be released in a month or so, and with the exception of Bluetooth on the ESP32, this Realtek module should match its capabilities quite well. Whether anyone can get an English datasheet is another matter, but if history is any indication a few English language RTL8710 forums will pop up a few hours after this is posted.

Thanks [sabas] for sending this in

Ask Hackaday: Is The ESP8266 5V Tolerant?

July 28, 2016 by Brian Benchoff 130 Comments

The ESP8266 is the reigning WiFi wonderchip, quickly securing its reputation as the go-to platform for an entire ecosystem of wireless devices. There’s nothing that beats the ESP8266 on a capability vs. price comparison, and this tiny chip is even finding its way into commercial products. It’s also a fantastic device for the hardware tinkerer, leading to thousands of homebrew projects revolving around this tiny magical device.

In every technical document, summary, and description of the ESP8266, the ESP8266 is said to be a 3.3V part. While we’re well into the age of 3.3V logic, there are still an incredible number of boards and hardware that still operate using 5V logic. Over on the Hackaday.io stack, [Radomir] is questioning this basic assumption. He’s wondering if the ESP8266 is 5V tolerant after all. If it is, great. We don’t need level converters, and interfacing the ESP to USB TTL serial adapters becomes much easier. Yes, you’ll still need to use a regulator if the rest of your project is running at 5V, but if the pins are 5V tolerant, interfacing the ESP8266 with a variety of hardware becomes very easy.

[Radomir]’s evidence for the possibility of 5V tolerant inputs comes from a slight difference in the official datasheet from Espressif, and the datasheet translated by the community before Espressif realized how many of these chips they were going to sell.

The best evidence of 5V tolerant pins might come from real-world experience — if you can drive a pin with 5V for months on end without it failing, there might be something to this claim. It’s not definitive, though; just because a device will work with 5V input pins for a few months doesn’t mean it won’t fail in the future. So far a few people have spoken up and presented ESPs directly connected to the 5V pin of an Arduino that still work after months of service. If this is evidence of 5V tolerant design or simply luck is another matter entirely.

While the official datasheet from Espressif lists a maximum V_IH of 3.3V, maximum specs rarely are true maximums — you can always push a part harder without things flying apart at the seams. Unfortunately, unless we hear something from the engineers at Espressif, we won’t know if the ESP8266 was designed to be 5V tolerant, if it can handle 5V signals reliably, or if 5V signals are a really good way to kill a chip eventually.

Lucky for us — and this brings us to the entire point of an Ask Hackaday column — a few Espressif engineers read Hackaday. They’re welcome to pseudonymously chime in below along with the rest of the peanut gallery. Failing that, the ESP8266 has been decapped; are there any die inspection wizards who can back up a claim of 5V tolerance for the GPIO? We’d also be interested in hearing any ideas for stress testing pin tolerance.

Dual Axis Solar Tracker With Online Energy Monitor

July 24, 2016 by Gerrit Coetzee 57 Comments

[Bruce Helsen] built this dual axis solar tracker as one of his final projects for school.

As can be experimentally verified in a very short timeframe, the sun moves across the sky. This is a particularly troublesome behavior for solar panels, which work best when the sun shines directly on them. Engineers soon realized that abstracting the sun away only works in physics class, and moved to the second best idea of tracking sun by moving the panel. Surprisingly, for larger installations the cost of adding tracking (and its maintenance) isn’t worth the gains, but for smaller, and especially urban, installations like [Bruce]’s it can still help.

[Bruce]’s build can be entirely sourced from eBay. The light direction is sensed via a very clever homemade directional light sensor. A 3D printer extruded cross profile sits inside an industrial lamp housing. The assembly divides the sky into four quadrants with a light-dependent resistor for each. By measuring the differences, the panel can point in the optimal direction.

The panel’s two axis are controlled with two cheap linear actuators. The brains are an Arduino glued to a large amount of solar support electronics and the online energy monitor component is covered by an ESP8266.

The construction works quite well. If you’d like to build one yourself the entire BOM, drawings, and code are provided on the instructables page.

MicroPython On The ESP8266: Kicking The Tires

July 21, 2016 by Elliot Williams 32 Comments

Scripting languages are for large computers, right? “Real” embedded device work is a hellish, never-ending cycle of code, compile, and re-flash. Well, I used to think so too, but with the proliferation of scripting and other interactive languages to microcontrollers over the last few years, the hurdle to interactive development on the small chips has gotten a lot lower.

On the ESP8266 platform, I’ve tried out NodeMCU’s Lua and ESP8266 BASIC. (For the last half-year, I’ve been using the awesome Mecrisp-Stellaris almost exclusively on the STM32F1xx and F4xx chips, but haven’t dipped into ESP8266 Forth yet.)

NodeMCU is great because it’s got everything you could want built in, and through cloud services it’s easy to get a tailored build made that maximizes free flash memory for your projects. I just don’t dig the asynchronous Lua thing (you might, try it!). ESP BASIC has a different set of libraries, and is missing MQTT for my purposes. Still it’s pretty slick, and worth a look.

So when the MicroPython folks announced that they were releasing the binary builds for the ESP, I thought it was time to give it a spin. I’ve used Python for nearly twelve years now, so it’s like a comfortable shoe for me. Would MicroPython be the same on the ESP8266? The short answer is yes and no.

Continue reading “MicroPython On The ESP8266: Kicking The Tires” →

Never Gonna Give Up Free WiFi

July 19, 2016 by Elliot Williams 44 Comments

Our conscience almost prevented us from posting this one. Almost.

What do people all around the world want most? Free WiFi. And what inevitable force do they want to avoid most, just after death and taxes? Rick Astley. As a getting-started project with the ESP8266, Hackaday.io user [jaime] built a “free WiFi portal” that takes advantage of people’s deepest desires. Instead of delivering sweet, high-bandwidth connectivity, once you click through the onerous terms and conditions, it delivers you a looped GIF with background music.

And all of this on $4 worth of hardware, with firmware assembled in the cloud and easily available to anyone. We live in a truly ~~frivolous~~ glorious age.

Digging through our archives, we found a number of Rickroll posts that we’d rather forget, but this steam-powered record player bears a second look.