arduino

2940 Articles

A Mega-Tiny Arduino

March 2, 2023 by 26 Comments

Integrated circuits, chipsets, memory modules, and all kinds of other transistor-based technology continues to get smaller, cheaper, and more energy efficient as time moves on. Not only are the components themselves smaller, but their supporting infrastructure is as well. Computers like the Raspberry Pi are about the size of a credit card and have computing power on the order of full-sized PCs from a few decades ago. The Arduino is no exception to this trend, either, and this new dev board called the Epi 32U4 might be the smallest ATmega platform we’ve seen so far.

As the name suggests, the board is based around the ATmega32U4 which is somewhat unique among Atmel chips in that it includes support for USB within the chip itself rather than relying on external translating circuitry. This makes it an excellent choice for any project which involves sending keyboard, mouse, or other peripheral information to a computer. This goes a few steps further with eliminating “bloat” compared to other boards, too — there’s no on-board voltage regulator, and just a single LEDs on pin 13.

One of the other features this board boasts over other small form factor boards is on-board USB-C, which is definitely a perk as more and more devices switch away from the various forms of older USB-type plugs. The project’s specifications are also available on this GitHub page for anyone that wants to produce their own. And, if you don’t have a 32U4 on hand and still want to build a keyboard project, it’s possible to get some other Arduinos to support these features but it’ll take a little more work.

Thanks to [Rasmus L] for the tip!

Digital Replica Of Antique Weather Monitoring Instrument

February 22, 2023 by 8 Comments

Computers and digital sensors have allowed for the collection and aggregation of data barely possible to imagine to anyone in the instrumentation scene even sixty years ago. Before that, things like weather stations, seismometers, level sensors, and basically any other way of gathering real data about the world would have been performed with an analog device recording the information on some sort of spool of paper. This was much more tedious but the one thing going for these types of devices was their aesthetic. [mircemk] is back to bring some of that design inspiration to a digital barometric display.

The barometer is based around an Arduino Arduino Nano and a relatively large I2C display to display the captured data. It also uses a BME 280 pressure sensor board, but the technical details of this project are not the focal point here. Instead, [mircemk] has put his effort in recreating the old analog barographs, which display barometric data on a spool of paper over time, on the I2C display. As the device measures atmospheric pressure, it adds a bar to the graph, displaying the data over time much as the old analog device would have.

We’ve discussed plenty of times around here that old analog meters and instrumentation like this recreation of a VU meter are an excellent way of getting a more antique aesthetic than is typically offered by digital replacements. Adding in a little bit of style to a project like this can go a long way, or you can simply restore the original antique instead.

How To Build Jenny’s Budget Mixing Desk

February 15, 2023 by 35 Comments

Jenny did an Ask Hackaday article earlier this month, all about the quest for a cheap computer-based audio mixer. The first attempt didn’t go so well, with a problem that many of us are familiar with: Linux applications really doesn’t like using multiple audio devices at the same time. Jenny ran into this issue, and didn’t come across a way to merge the soundcards in a single application.

I’ve fought this problem for a while, probably 10 years now. My first collision with this was an attempt to record a piano with three mics, using a couple different USB pre-amps. And of course, just like Jenny, I was quickly frustrated by the problem that my recording software would only see one interface at a time. The easy solution is to buy an interface with more channels. The Tascam US-4x4HR is a great four channel input/output audio interface, and the Behringer U-PHORIA line goes all the way up to eight mic pre-amps, expandable to 16 with a second DAC that can send audio over ADAT. But those are semi-pro interfaces, with price tags to match.

But what about Jenny’s idea, of cobbling multiple super cheap interfaces together? Well yes, that’s possible too. I’ll show you how, but first, let’s talk about how we’re going to control this software mixer monster. Yes, you can just use a mouse or keyboard, but the challenge was to build a mixing desk, and to me, that means physical faders and mute buttons. Now, there are pre-built solutions, with the Behringer X-touch being a popular solution. But again, we’re way above the price-point Jenny set for this problem. So, let’s do what we do best here at Hackaday, and build our own. Continue reading “How To Build Jenny’s Budget Mixing Desk” →

Connecting A Keyboard To A Vintage PC-XT, The Hard Way

February 7, 2023 by 16 Comments

We’re not sure if there’s any single characteristic that qualifies someone as a hacker. After all, we’re a pretty eclectic bunch, with skills that range all over the map, and what one person feels is trivial, others would look upon as black magic. But there’s one thing we’re sure of: if you find yourself reading the original POST code for the PC-XT motherboard just to get a keyboard working, you’re pretty much our kind of people.

That was the position [Anders Nielsen] found himself in as work progresses on his “PC-XT from Scratch” project, which seeks to build a working mid-80s vintage IBM Model 5160 using as many period-correct parts as possible. The first installment of the series featured the delicate process of bringing the motherboard up, lest the magic smoke was released. After seeing some life out of the old board, [Anders] needed a little IO, specifically video and keyboard. The video side of the equation was relatively trivial, with an early-90s VGA card from eBay — not exactly period correct, but good enough to get something to display. Continue reading “Connecting A Keyboard To A Vintage PC-XT, The Hard Way” →

A vintage film camera with a bright light emitting diode shining through it, next to electronic equipment to measure the shutter speed

Clock Your Camera With This Shutter Speed Tester

February 7, 2023 by 27 Comments

Camera shutter speed is an essential adjustment in photography – along with the aperture, the shutter moderates the amount of light entering the camera. Older cameras (and some newer ones) use mechanical shutters that creep out-of-spec over the years, so [Dean Segovis] built a handy shutter speed tester.

With just a handful of basic components, this project is a great one for beginners to sink their teeth into. The tester is based around a photoresistor that measures light from another source (a flashlight) that travels through the camera body. When the shutter on the camera is released, the shutter speed can be measured and displayed on the OLED screen. An Arduino naturally handles all the computational duties. The whole thing can be easily assembled on a breadboard in just a couple of minutes.

The original project by [hiroshootsfilm] is over on Project Hub, however [Dean] takes a deeper dive with some code troubleshooting, as well as trying out a variety of old film cameras with the breadboard tester. His testing revealed that the photoresistor was better able to detect shutter speed when the camera lens was removed, which is a hot tip for anyone else that wants to try this.

While it’s not surprising that these older cameras are having trouble with their mechanical shutters, this little tester would be an invaluable tool when it comes time to start tweaking shutter mechanisms. If this project has brought out the shutterbug in you, make sure to check out this brain transplant for a Polaroid 100-series Packfilm camera that we covered way back in 2011.

Continue reading “Clock Your Camera With This Shutter Speed Tester” →

Arduino Does SDI Video With FPGA Help

February 6, 2023 by 12 Comments

If you are running video around your home theater, you probably use HDMI. If you are running it in a professional studio, however, you are probably using SDI, Serial Digital Interface. [Chris Brown] looks at SDI and shows a cheap SDI signal generator for an Arduino.

On the face of it, SDI isn’t that hard. In fact, [Chris] calls it “dead simple.” The problem is the bit rate which can be as high as 1.485 Gbps for the HD-SDI standard. Even for a super fast processor, this is a bit much, so [Chris] turned to the Arduino MKR Vidor 4000. Why? Because it has an FPGA onboard. Alas, the FPGA can’t do more than about 200 MHz, but that’s fast enough to drive an external Semtech GS296t2 serializer which is made to drive SDI signals.

The resulting project contains the Arduino, the serializer, a custom PCB, and both FPGA and microcontroller code. While the total cost of the project was a little under $200, that’s still better than the $350 to $2000 for a commercial SDI signal generator.

If you want to play along, the files are out on GitHub. We used the Vidor back in 2018 when it first came out. If you need a quick start on FPGAs, there’s always our boot camp.

Mechanical Keyboard Is Also A Mouse

February 4, 2023 by 15 Comments

The mechanical keyboard community is a vibrant, if not fanatical, group of enthusiasts determined to find as many possible ways of assembling, building, and using as many high-quality keyboards as possible. With so many dedicated participants, most things that can be done with a keyboard already have been done. So when something as unique as this split keyboard that also doubles as a mouse pops up, we take notice.

The keyboard is a custom build from [Taliyah Huang] which uses a pair of Arduinos, one in each half of the keyboard, to communicate key and mouse information to a third Arduino which is plugged in to her laptop. The right-hand half of the keyboard also includes the circuitry from an optical mouse, which gets powered up when the caps lock button is held down. When activated, this allows the keyboard to be used as a mouse directly. It also includes support for most Mac gestures as well, making it just as useful as a trackpad.

While there were some problems with the design, including being slightly too tall to be ergonomic and taking nearly 24 hours of soldering to complete, the prototype device is an interesting one especially since it allows for full control of a computer without needing a dedicated mouse. For other unique mechanical keyboard concepts, we recently featured this build which takes design and functionality cues from the Commodore 64.

Continue reading “Mechanical Keyboard Is Also A Mouse” →