Streaming Video From An ESP32

September 5, 2023 by Bryan Cockfield 11 Comments

The ESP32, while first thought to be little more than a way of adding wireless capabilities to other microcontrollers, has quickly replaced many of them with its ability to be programmed as its own platform rather than simply an accessory. This also paved the way for accessories of its own, such as various sensors and even a camera. This guide goes over taking the input from the camera and streaming it out over the network to multiple browsers.

On the server side of things, the ESP32 and its attached camera are set up with MQTT, a lightweight communications protocol which uses a publish/subscribe model to send information. The ESP32 is configured to publish its images only, but not subscribe to any other nodes. On the client side, the browser runs a JavaScript program which is able to gather these images and stitch them together into a video.

This can be quite a bit of data to send out over the ESP32’s compact hardware, so there are some tips and tricks for getting more out of these little devices, including using an external antenna for better Wi-Fi signal, or omitting it entirely in favor of Ethernet. As far as getting a lot out of a tiny microcontroller, though, leveraging MQTT really helps the ESP32 go a long way. These chips have come along way since they were first introduced; they’re powerful enough to act as 8-bit gaming consoles too.

Thanks to [Surfskidude] for the tip!

Litter Box Sensor Lets You Know Exactly What The Cat’s Been Up To

August 17, 2023 by Dan Maloney 16 Comments

In our experience, there’s rarely any question when the cat uses the litter box. At all. In the entire house. For hours. And while it may be instantly obvious to the most casual observer that it’s time to clean the thing out, that doesn’t mean there’s no value in quantifying your feline friend’s noxious vapors. For science.

Now of course, [Owen Ashurst] could have opted for one of those fancy automated litter boxes, the kind that detects when a cat has made a deposit and uses various methods to sweep it away and prepare the box for the next use, with varying degrees of success. These machines seem like great ideas, and generally work pretty well out of the box, but — well, let’s just say that a value-engineered system can only last so long under extreme conditions. So a plain old-fashioned litterbox suffices for [Owen], except with a few special modifications. A NodeMCU lives inside the modesty cover of the box, along with a PIR sensor to detect the cat’s presence, as well as an MQ135 air quality sensor to monitor for gasses. It seems an appropriate choice, since the sensor responds to ammonia and sulfides — both likely to be present after a deposit. Continue reading “Litter Box Sensor Lets You Know Exactly What The Cat’s Been Up To” →

Pretty Small Robot Is Capable, Nonetheless

May 30, 2023 by Lewin Day 5 Comments

When science fiction authors imagined robots in the 20th century, many of them were huge imposing steel automatons. [Shane]’s designs for the Pretty Small Robot are quite contrary to that, being tiny in stature and cute in affect .

The whole robot is an exploration in nifty engineering. It uses an easy clip-together structure with fasteners and glue not required. The chassis is 3D printed, with all the components sliding into place. Two small DC gearmotors are used for differential drive, with each side of the robot having a pair of wheels wrapped in a rubber band for traction. The brains of the robot is an ESP32, providing it with both plenty of processing power and good connectivity options. Control is over WiFI via MQTT.

At this stage the robot doesn’t do a whole lot, though [Shane] has some exciting plans. He’d like to add a camera in future and let it explore a maze under human command.

If you’ve ever wanted to build a robot with an almost coin-sized foot print, this build is for you. Files are available on GitHub for those wishing to dive deeper. Video after the break.

Continue reading “Pretty Small Robot Is Capable, Nonetheless” →

Hack Simple

May 27, 2023 by Elliot Williams 7 Comments

Here at Hackaday, we definitely love to celebrate the hard hacks: the insane feats of reverse engineering, the physics-defying flights of fancy, or the abuse of cutting edge technology. But today I’d like to raise a rhetorical glass in tribute of the simple hacks. Because, to be perfectly honest, the vast majority of my hacks are simple hacks, and it’s probably the same for you too. And these often go unsung because, well, they’re simple. But that doesn’t mean that something simple can’t be helpful.

Case in point: an ESP8266 press-buttons device that we featured this week. It doesn’t do much. It’s main feature is that it connects to a home automation network over WiFi and enables you to flip three relays. Wires coming off the board are to be soldered to the not-yet-smart device in question, simply connected to each side of the button you’d like to press. In the example, a coffee machine was turned on and the “go” button pressed, automating one of the most essential kitchen rituals. While recording the podcast, I realized that I’ve built essentially this device and have it controlling our house’s heating furnace.

For the experienced hacker, there’s not much here. It’s a simple board design, the software heavily leverages ESPHome, so there’s not much work on that front either. But imagine that you lacked any of the wide-ranging skills that it takes to make such a device: PCB layout, ESP8266 software wrangling, or the nuances of designing with relays. You could just as easily build this device wrong as right. The startup costs are non-trivial.

Making a simple design like this available to the public isn’t a technical flex, and it’s not contributing to the cutting edge. But it just might be giving someone their first taste of DIY home automation, and a sweet taste of success. There’s not much easier than finding a switch and soldering on two wires, but if that’s the spark that pushes them on their path to greater hacks, that’s awesome. And even if it doesn’t, at least it’s another appliance under user control, connected to a private WiFi network rather than spying you out and phoning home to Big Toaster.

So here’s to the simple hacks!

ESP8266 Coaster Keeps Your Drink Warm

January 27, 2023 by Abe Connelly 5 Comments

Looking for the perfect winter desk accessory? [Wq] has created a beautiful coaster made out of PCBs that can keep your drink warm with an internal heater. (Chinese).

An ESP8266 sits as the main controller, with an additional MQTT control option, where the whole unit is powered over a USB-C connection. On board PCB traces, in the shape of a Hilbert curve, create the heating element used to heat beverages placed on the coaster, where [Wq] reports a measured resistance of the PCB trace network at 1.2 ohms. [Wq] writes that an AON6324 MOSFET replaces the D4184 that was previously being used, but might need some testing to get working properly. There are two capacitive touch sensors which has a TTP223E capacitive touch controller attached to detect input, with a multi-colored FM-3528 RGB LED for user feedback.

We love the artistry that went into building the coaster. For adventurous hackers wanting to build their own, the bill of materials (BOM), source code and board files are all available. We’ve seen everything from coasters and to PCB reflow boards, so it’s nice to see experimentation with a combination of these ideas.

Arduino Library Brings Rtl_433 To The ESP32

January 13, 2023 by Tom Nardi 9 Comments

If you have an RTL-SDR compatible radio there’s an excellent chance you’ve heard of the rtl_433 project, which lets you receive and decode signals from an ever-expanding list of supported devices in the ISM radio bands. It’s an incredibly useful piece of software, but the fact that it requires an external software defined radio and a full-fledged computer to run dictated the sort of projects it could realistically be used for.

But thanks to the rtl_433_ESP Arduino library developed by [NorthernMan54], we’re now able to pack that functionality into a much smaller package. All you need is an ESP32 microcontroller and a CC1101 or SX127X transceiver module. If you’re looking for a turn-key hardware platform, the documentation notes the LILYGO LoRa32 V2 board includes the required hardware, plus adds a handy OLED display and microSD slot. It should be noted that the range of these radios don’t compare particularly well to a full-size RTL-SDR device, but that probably won’t come as much of a surprise. Continue reading “Arduino Library Brings Rtl_433 To The ESP32” →

Weasley Clock For Magically Low Cost

November 24, 2022 by Bryan Cockfield 12 Comments

For those unfamiliar with the details of the expansive work of fiction of Harry Potter, it did introduce a few ideas that have really stuck in the collective conscious. Besides containing one of the few instances of time travel done properly and introducing a fairly comprehensive magical physics system, the one thing specifically that seems to have had the most impact around here is the Weasley family clock, which shows the location of several of the characters. We’ve seen these built before in non-magical ways, but this latest build seeks to drop the price tag on one substantially.

To do this, the build relies on several low-cost cloud computing solutions and smartphone apps to solve the location-finding problem. The app is called OwnTracks and is an open-source location tracker which can report data to any of a number of services. [Simon] sends the MQTT data to a cloud-based solution called HiveMQCloud, but you could send it anywhere in principle. With the location tracking handled, he turns to some very low-cost Arduinos to control the stepper motors which point the clock hands to the correct locations on the face.

While the build does rely on a 3D printer for some of the internal workings of the clock, this does bring the cost down substantially when compared to other options. Especially when compared to this Weasley family clock which was built into a much larger piece of timekeeping equipment, having an option for a lower-cost location-tracking clock face like this one is certainly welcome.