Arduino Library Brings Rtl_433 To The ESP32

January 13, 2023 by 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” →

A small 16x2 LCD display housed in a green and yellow hobby box.

Arduino-Powered Info Display For Your Windows Computer

January 10, 2023 by 23 Comments

If you’ve been pining for a retro-chic 16×2 LCD display to enhance your Windows computing experience, then [mircemk] has got you covered with their neat Windows-based LCD Info Panel.

Your everyday garden variety Arduino is the hero here, sitting between the computer’s USB port and the display to make the magic happen. Using the ‘LCD Smartie‘ software, the display can serve up some of your typical PC stats such as CPU and network utilization, storage capacity etc. It can also display information from BBC World News, email clients, various computer games and a world of other sources using plugins.

It’s clear that the intention here was to include the display inside your typical PC drive bay, but as you can see in the video below, this display can just about fit anywhere. It’s not uncommon to see similar displays on expensive ‘gamer’ peripherals, so this might be an inexpensive way for someone to bring that same LED-lit charm to their next PC build. You probably have these parts sitting in your desk drawer right now.

If you want to get started building your own, there’s more info over on the Hackaday.io page. And if PC notifications aren’t your jam, it’s worth remembering that these 16×2 displays are good for just about anything, like playing Space Invaders.

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Arduino Synthesizer Uses Modified Slide Pots

January 6, 2023 by 7 Comments

There comes a point in every Arduino’s life where, if it’s lucky, it becomes a permanent fixture in a project. We can’t think of too many better forever homes for an Arduino than inside of a 3D-printed synthesizer such as this 17-key number by [ignargomez] et al.

While there are myriad ways to synthesizer, this one uses the tried-and-true method of FM synthesis courtesy of an Arduino Nano R3. In addition to the 17 keys, there are eight potentiometers here — four are used for FM synthesis control, and the other four are dedicated to attack/delay/sustain/release (ADSR) control of the sound envelope.

One of the interesting things here is that [ignargomez] and their team were short a few regular pots and modified a couple of slide pots for circular use — we wish there was more information on that. As a result, the 3D printed enclosure underwent several iterations. Be sure to check out the brief demo after the break.

Don’t have any spare Arduinos? The BBC Micro:bit likes to make noise, too.

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Kids’ Jukebox Based On Arduino With RFID

December 16, 2022 by 10 Comments

Consumer electronics aimed at young children tend to be quite janky and cheap-looking, and they often have to be to survive the extreme stress-testing normal use in this situation. You could buy a higher quality item intended for normal use, but this carries the risk of burning a hole in the pockets of the parents. To thread the needle on this dilemma for a child’s audiobook player, [Turi] built the Grimmboy for a relative of his.

Taking its name from the Brothers Grimm, the player is able of playing a number of children’s stories and fables in multiple languages, with each physically represented by a small cassette tape likeness with an RFID tag hidden in each one. A tape can be selected and placed in the player, and the Arduino at the center of it will recognize the tag and play the corresponding MP3 file stored locally on an SD card. There are simple controls and all the circuitry to support its lithium battery as well. All of the source code that [Turi] used to build this is available on the project’s GitHub page.

This was also featured at the Arudino blog as well, and we actually featured a similar project a while ago with a slightly different spin. Both are based on ideas from Tonuino, an open source project aimed at turning Arduinos into MP3 players. If you’re looking to build something with a few more features, though, take a look at this custom build based on the RP2040 microcontroller instead.

A slide carousel with a DSLR attached to its lens output

Digitize Your Slide Deck With This Arduino-Powered Slide Carousel

November 15, 2022 by 27 Comments

If you’re above a certain age, you probably remember the atmosphere of a pre-Powerpoint 35 mm slide show. The wobbly screen being unrolled, the darkened room, the soft hum of the projector’s fan, the slightly grainy picture on the screen and that unmistakable click-whoosh-clack sound as the projector loaded the next slide. Nowadays you’ll be hard pressed to find anyone willing to set up a screen and darken the room just to watch a few photos, so if you still have any slides lying around you’ll probably want to digitize them. If you’ve also kept your projector then this doesn’t even have to be that difficult, as [Scott Lawrence] shows in his latest project.

[Scott] made a setup to directly connect a DLSR, in this case a Nikon D70, to a Kodak 760 slide carousel. The attachment is made through a 3D-printed adapter that fits onto the Nikon’s macro lens on one side and slides snugly into the carousel’s lens slot on the other. The adapter also holds an IR transmitter which is aimed at the camera’s receiver, in order to trigger its remote shutter release function.

The carousel’s original light source was replaced with a compact LED studio light, which allows for precise brightness control and of course remains nice and cool compared to the original incandescent bulb. The light, camera and carousel motor are all controlled through a central user interface driven by an Arduino Leonardo which can automatically advance the carousel and instruct the camera to take a picture, thereby taking the hard work out of digitizing huge stacks of slides.

[Scott] plans to make the software and STL files available on GitHub soon, so anyone can go ahead and turn their projector into a digitizer. If you’ve misplaced your projector however, a simple 3D-printed slide adapter for your camera also works for small slide decks.

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Screenshot of the Arduino Lab for MicroPython

Arduino Brings A MicroPython IDE

November 14, 2022 by 52 Comments

Both Arduino and MicroPython are giants when it comes to the electronics education area, and each one of them represents something you can’t pass up on as an educator. Arduino offers you a broad ecosystem of cheap hardware with a beginner-friendly IDE, helped by forum posts explaining every single problem that you could and will stumble upon. MicroPython, on the other hand, offers a powerful programming environment ripe for experimentation, and doesn’t unleash a machine gun fire of triangle brackets if you try to parse JSON slightly incorrectly. They look like a match made in heaven, and today, from heaven descends the Arduino Lab for MicroPython.

This is not an Arduino IDE extension – it’s a separate Arduino IDE-shaped app that does MicroPython editing and uploads code to your board from a friendly environment. It works over a serial port, and as such, the venerable ESP8266-based boards shouldn’t be be left out – it even offers file manager capabilities! Arduino states that this is an experimental effort – it doesn’t yet have syntax checks, for instance, and no promises are made. That said, it already is a wonderful MicroPython IDE for beginner purposes, and absolutely a move in the right direction. Want to try? Download it here, there’s even a Linux build!

High-level languages let you build projects faster – perfect fit for someone getting into microcontrollers. Hopefully, what follows is a MicroPython library manager and repository! We’ve first tried out MicroPython in 2016, and it’s come a long way since then – we’ve seen quite a few beginner-friendly MicroPython intros, from a gaming handheld programming course, to a bipedal robot programming MicroPython exploration. And, of course, you can bring your C libraries with you.

Walnut Case Sets This Custom Arduino-Powered RPN Calculator Apart From The Crowd

November 3, 2022 by 12 Comments

How many of us have an everyday tool that’s truly unique? Likely not many of us; take a look around your desk and turn out your pockets, but more often than not, what you’ll find is that everything you have is something that pretty much everyone else on the planet could have bought too. But not so if you’ve got this beautiful custom RPN calculator in a wooden case.

This one comes to us from [Shinsaku Hiura], who generally dazzles us with unique mechanical clocks and displays. This calculator solves a more practical problem — the dearth of RPN calculators on the market with the correct keyboard feel, specifically with the large keys and light touch he desired. Appropriately, the build started with a numeric keypad, which once liberated of its USB interface was reverse-engineered to figure out how the matrix was wired. Next up, a custom PCB to connect the keypad to an Arduino and a 20×4 LCD display was milled up, while a test case was designed and printed to check fitment. The final case was milled from a block of solid walnut and fitted with an acrylic window, for a sharp look with clean lines and pleasing colors.

As for the calculator itself, the demo below shows it going through its paces. The code is clever because it leverages the minimal number of keys available by hiding all the scientific and engineering functions behind a “secret silver key” that was once the equals key and obviously not needed in RPN. Hats off to [Shinsaku] for a handsome and unique addition to his desk.

Continue reading “Walnut Case Sets This Custom Arduino-Powered RPN Calculator Apart From The Crowd” →