Bluetooth Intervalometer Makes Time Lapses Easy

February 21, 2020 by Zoe Skyforest 5 Comments

Taking timelapses is a fun pastime of many a photographer. While most modern cameras have some features to pull this off, if you want to get really into it, you’ll want an intervalometer to run the show. Chasing just that, [Zach] decided that rather than buying off-the-shelf, a DIY build was in order.

The build relies on an Arduino Nano to run the show, in combination with the popular HC-05 Bluetooth module. The Bluetooth module allows the device to communicate with a smartphone app which [Zach] created using RoboRemo. This is a platform that makes creating custom USB, WiFI and Bluetooth apps easy for beginners. The app sends instructions to the intervalometer regarding the number of photos to take, and the time to wait between each shot. Then, it triggers the time lapse, and the Arduino triggers the camera by shorting the relevant pins on a TRS plug inserted into the camera.

It’s a straightforward build that most hackers could probably complete with parts from the junk box. Plus, building your own offers the possibility of customising it exactly to your needs. Of course, you can eschew modernity and do things mechanically instead. Video after the break.

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Irrigation Controller Uses Google Calendar To Make Things Easy

February 20, 2020 by Zoe Skyforest 19 Comments

Irrigation controllers have been around for a long time, often using similar hardware inside that would be familiar to the average maker. However, many of the products on the shelf at your local hardware store can be quite expensive for what amounts to a microcontroller, display, and relay board. [oscillatory] had such a rig, but wanted to bring it into the 21st century, IOT style.

The existing Holman irrigation system consisted of a control box, hooked up to four solenoid valves controlled by relays. [oscillatory] decided that replacing this with something fancier would thus be straightforward. A relay board packing an ESP8266 was sourced, and flashed with the Tasmota firmware. This was then hooked up to run off the Holman’s 24 VAC supply via a CCTV power supply, allowing the new controller to be run in parallel with the existing hardware, just in case. Scheduling is then controlled by Google Calendar, in concert with Home Assistant.

[oscillatory] now has a watering system that can be controlled over the web, and without the need to install any custom apps. Simply creating a calendar entry is enough for the system to spring into action. We’ve seen others use a similar approach, too. It’s a great example of using off-the-shelf parts to whip up a useful custom home automation setup!

Stout Homebrew Radio Pumps Out 200W Of AM Goodness

February 20, 2020 by Zoe Skyforest 7 Comments

In this day and age, with cheap online shopping, software defined radio and bargain-basement Baofengs from China, the upstart radio ham is spoilt for choice. Of course, there’s nothing quite like the charm of keying up your own homebrewed rig, cooked up in the garage from scratch. [Paul], aka [VK3HN], knows just how it feels, and put together an epic 200 watt Class D AM rig to blast his signal on the airwaves.

An example of an Arduino used in one of [Paul]’s builds.

It’s a build following on from the work of another radio ham, [Laurie], aka [VK3SJ]. Younger hackers will note the Arduino Nano at the heart of the project, running the VFO and handling all the relevant transmit/receive switching. We can only imagine how welcome modern microcontrollers must have been to old hands at amateur radio, making synthesizing all manner of wild frequencies a cinch.

The amount of effort that has gone into the build is huge. There are handwound coils for the PWM low-pass filter, and the PCB is home-etched in ferric chloride, doing things the old-school way. There’s also a healthy pile of dead components that sacrificed their lives in the development of this build. Perhaps our favorite part is the general aesthetic – we can’t get over the combination of hand-drawn copper traces and off-the-shelf Arduinos.

Many components perished in the development of this powerful rig.

It’s a build that far exceeds the Australian legal limits, so it only gets keyed up to 120W in real use. This has the benefit of keeping the radio operating far in the safety zone for its components, helping keep things cool and stable. We’re sure [Paul] will be getting some great contacts on this rig. If you’re suffering from low power yourself, consider an amplifer build. Video after the break.

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We Ruined Status LEDs; Here’s Why That Needs To Change

February 20, 2020 by Zoe Skyforest 259 Comments

Ah, the humble status LED. Just about every piece of home electronics, every circuit module, and anything else that draws current seems to have one. In the days of yore, a humble indicator gave a subtle glow from behind a panel, and this was fine. Then the 1990s happened, and everything got much much worse.

It’s Not The Technology, It’s How You Use It

With great brightness, comes great responsibility.

The 1990s brought us much good: Nirvana, Linux, and of course the blue LED. Much like “Teen Spirit”, the latter quickly fell into overuse: the technology rapidly became the sigil of all that was new and great, much to the ocular pain of the buying public.

This decision ranks up there for stupidity with other such questionable choices as hiring a rental car at the airport, or invading Russia in the winter. A status LED, most would agree, is there to indicate status. It need only deliver enough light to be seen when observed by a querying eye. What it need not do is glow with the intensity of a dying star, or illuminate an entire room for that matter. But, in the desperate attempts of product designers to appear on the cutting edge, the new, brighter LED triumphed over all in these applications. Continue reading “We Ruined Status LEDs; Here’s Why That Needs To Change” →

Password Keeper Uses Off-The-Shelf Formfactor

February 19, 2020 by Zoe Skyforest 25 Comments

With every website these days demanding the creation of an account, it can become difficult to remember so many logins. Each password should ideally be unique, lest a leak from your fantasy football game cost you thousands in stolen bitcoins. To help, [vcch] developed a password vault, using an interesting off-the-shelf platform.

The platform in question is the M5stickC, which packs an ESP32, color LCD, and battery into an attractive orange enclosure. It’s even got USB-C, making it a tool with an eye on the future. It serves as a quick way to get a basic IOT project up and running, without having to fuss about designing your own enclosure or basic power supply hardware.

On this platform, [vcch] created a tool to make keeping track of passwords easy. The PassStrong, as it’s called, can store a huge number of passwords, and communicates with the host PC over Bluetooth. The interface makes good use of the LCD, displaying the current mode and function of each button on the device for the user. It’s capable of working in both QWERTY and AZERTY environments, which should appeal to European users.

The M5StickC is a perfect choice in this regard, packing enough buttons and the required Bluetooth hardware to get the job done. No need to spend any time integrating modules – simply open the box and get to coding. We expect to see more developments in this space in future, and look forward to the efficiency gains this will bring to all kinds of projects!

Lil’ ESP32 Bot Does Remote Surveillance, And It’s Easy

February 19, 2020 by Zoe Skyforest 7 Comments

Digital cameras have been around for a long time, as have small remote control robotics platforms. However, combining the two has really only come into its own in the last decade or so, as more bandwidth has become available to the home tinkerer. This ESP32-CAM surveillance bot is a great example of what was once hard becoming trivially easy.

It’s a case of standing on the shoulders of giants. The ESP32-CAM is a device that allows one to stream live video images over a network using existing example code. In this case, it’s combined with an L298N DC motor driver which allows the Adafruit robot platform to be steered like a tank via its two wheels. A pair of SG90 servos then serve as a pan/tilt mechanism to further improve the robot’s field of view.

If you aimed to attempt this back in 2010, you’d have spent six months figuring out how to get a microcontroller to talk to a small camera module. Only then could you consider solving the multitude of other problems presented by getting the video feed off the bot to somewhere useful. These days, you can order a bunch of parts online and have it up and running in a couple hours. This project from 2013 serves as an example of how much things have changed in the intervening years. Video after the break.

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MNIST Clock Uses Famous Training Database

February 18, 2020 by Zoe Skyforest 6 Comments

When training neural networks to recognise things, what you need is a big pile of training data. You then need a subsequent pile of testing data to verify that the network is working as you’d expect. In the field of handwriting recognition, the MNIST database is commonly used to train networks on handwritten numerals. After [Evan Pu] mentioned it would be fun to use this data to create a clock, [Dheera Venkatraman] got down to work.

The original sketch which inspired the build.

The MNIST database contains 60,000 training images, and 10,000 test images. [Dheera] selected an ESP32 to run the project, which packs 4MB of flash storage – more than enough to store the testing database at 196 bytes per numeral. This also gives the project network connectivity, allowing the clock to use Network Time Protocol to stay synchronised – thus eliminating the need for an external RTC. Digits are displayed on four separate e-ink displays, which fits well with the hand-drawn aesthetic. It also means the clock doesn’t unduly light up the room at night.

It’s a fun project that will likely draw a knowing chuckle from those working in the field of handwriting recognition. We’d love to have one on our desk, too. If you’re thinking of attempting a build yourself, check out our recent contest for more inspiration!