touchscreen

79 Articles

Using A Smartphone As A Touchscreen For Arduino

December 16, 2024 by 22 Comments

If you want a good display and interface device for an embedded project, it’s hard to look past an old smartphone. After all, you’ve got an excellent quality screen and capacitive touch interface all in the same package! [Doctor Volt] explains how to easily set up your old smartphone to work as a touchscreen for your Arduino.

[Doctor Volt] demonstrates the idea with a 2018 Samsung Galaxy A8, though a wide variety of Android phones can be put to use in this way. The phone is connected to the Arduino via a USB-to-serial converter and an OTG cable. Using a USB-C phone with Power Delivery is ideal here, as it allows the phone to be powered while also communicating with the Arduino over USB.

The RemoteXY app is built specifically for this purpose. It can be installed on an Android phone to allow it to communicate effectively with Arduino devices, which run the RemoteXY library in turn. Configuring the app is relatively straightforward, with a point-and-click wizard helping you designate what hardware you’re using and how you’ve got it hooked up. [Doctor Volt] does a great job of explaining how to hook everything up, and how to build some simple graphical interfaces.

There are a ton of display and interface options in the embedded space these days, many of which can be had cheaply off the shelf. Still, few compete with the resolution and quality of even older smartphones. It’s a neat project that could come in very handy for your next embedded build! Video after the break.

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Raspinamp: It Really Replicates Questionable Activities Involving Llamas

March 7, 2024 by 23 Comments

In the late 90s as MP3s and various file sharing platforms became more common, most of us were looking for better players than the default media players that came with our operating systems, if they were included at all. To avoid tragedies like Windows Media Center, plenty of us switched to Winamp instead, a much more customizable piece of software that helped pave the way for the digital music revolution of that era. Although there are new, official versions of Winamp currently available, nothing really tops the nostalgia of the original few releases of the software which this project faithfully replicates in handheld form.

The handheld music player uses a standard Raspberry Pi (in this case, a 3B) and a 3.5″ TFT touchscreen display, all enclosed in a clear plastic case. With all of the Pi configuration out of the way, including getting the touchscreen working properly, the software can be set up. It uses QMMP as a media player with a Winamp skin since QMMP works well on Linux systems with limited resources. After getting it installed there’s still some configuration to do to get the Pi to start it at boot and also to fit the player perfectly into the confines of the screen without any of the desktop showing around the edges.

Although it doesn’t use the original Winamp software directly, as that would involve a number of compatibility layers and/or legacy hardware at this point, we still think it’s a faithful recreation of how the original looked and felt on our Windows 98 machines. With a battery and a sizable SD card, this could have been the portable MP3 player many of us never knew we wanted until the iPod came out in the early 00s, and would certainly still work today for those of us not chained to a streaming service. A Raspberry Pi is not the only platform that can replicate the Winamp experience, though. This player does a similar job with the PyPortal instead.

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Streaming Deck Removes Need For Dedicated Hardware

February 25, 2024 by 11 Comments

Streaming content online has never been more popular than it is now, from YouTube to Twitch there are all kinds of creators around with interesting streams across a wide spectrum of interests. With that gold rush comes plenty of people selling figurative shovels as well, with audio mixing gear, high-quality web cams, and dedicated devices for controlling all of this technology. Often these devices take the form of a tablet-like device, but [Lenochxd] thinks that any tablet ought to be able to perform this task without needing dedicated, often proprietary, hardware.

The solution offered here is called WebDeck, an application written in Flask that turns essentially any device with a broswer into a stream control device. Of course it helps to have a touch screen as well, but an abundance of tablets and smartphones in the world makes this a non-issue. With the software running on the host computer, the streamer can control various aspects of that computer remotely by scanning a QR code which opens a browser window with all of the controls accessible from within. It has support for VLC, OBS Studio, and Spotify as well which covers the bases for plenty of streaming needs.

Currently the host software only runs on Windows, but [Lenochxd] hopes to have MacOS and Linux versions available soon. We’re always in favor of any device that uses existing technology and also avoids proprietary hardware and software. Hopefully that’s a recipe to avoid planned obsolescence and unnecessary production. If you prefer a version with a little bit of tactile feedback, though, we’ve seen other decks which add physical buttons for quick control of the stream.

New Part Day: Flush-mount Touchscreen For Retro PC Build

December 11, 2023 by 19 Comments

I recently had the opportunity to purchase an early version of a new display, and it happened to be just the thing I needed to make a project work. That display is the Elecrow 11.6″ CrowVision touchscreen slated for release in 2024. Preorders are being accepted on Crowd Supply.

I had an idea for a retro-inspired PC build that was just waiting for a screen like this. I’ll talk about the display and what’s good about it, then showcase the build for which it was the missing piece. If you’ve got a project waiting for something similar, maybe this part will provide what you need or at least turn on some new ideas.

What Is It?

The CrowVision 11.6″ 1366 x 768 touchscreen has an HDMI input, USB output for touch data, and accepts 12 V DC. It’s made to interface easily with a Raspberry Pi or other SBC (single-board computer).

Personally I consider a display like this to be the minimum comfortable size for using desktop type applications in a windowed environment. Most displays in this space are smaller. But aside from that, what helps make it useful for embedding into a custom enclosure is the physical layout and design.

Since I was looking for the largest display that could be flush-mounted in an enclosure without a lot of extra space around the display’s sides, it was just what I needed. The integrated touchscreen is a nice bonus.

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Raspi-Powered Typewriter Is A Real MUSE

September 5, 2023 by 4 Comments

Thanks to parenting and life in general, [Brendan] had fallen out of the habit of writing and wasn’t happy about it. If you write anything ever, you already know there are endless distractions when it comes to doing so on a computer. Sure, there always typewriters, but it’s difficult to do anything with the fruits of a typewriter other than scan it in or make copies, and it’s basically un-editable except by hand.

Instead of just sitting down and writing, [Brendan] did what any of us would do — took the time to create an elegant solution. The Most Unusual Sentence Extractor, or MUSE, is a Raspberry Pi-based typewriter with the best of both worlds. It’s essentially a word processor, but it can save to the cloud.

[Brendan] found beautiful inspiration in the Olympia Traveller de Luxe typewriter, a delightfully boxy affair made in the 1960s and 70s with lovely keys. Starting with a 68Keys.io board, [Brendan] set about re-creating the lines of the Traveller de Luxe in Tinkercad.

Since it doesn’t really need a platen, this was the perfect place to mount a screen using black PVC. At first, [Brendan] was going to use an e-ink screen, but a mishap led to a better solution — an LCD touchscreen that makes document navigation a breeze.

We absolutely love the look of this machine, which was obviously a labor of love. And yeah, it does the trick:[Brendan] is writing again. Though it maybe be inconvenient, we agree that it really is nice to have a dedicated workstation for certain things.

Looking for the complete opposite of this project? How about a Chat GPT-assisted daisywheel typewriter?

Pi Zero Runs DOOM Via Wireless Power

July 15, 2023 by 8 Comments

What’s better than a Raspberry Pi Zero running DOOM on a 3.5″ touchscreen? Running it over wireless power, of course!

[atomic14] has been interested in wireless power for a while, and while most of the hardware he’s tested over the years has been less than impressive, he demonstrates one that’s able to reliably deliver 5 V at about 1 A which is more than enough to boot a Raspberry Pi W2 into X and launch DOOM. But while that’s neat, he explains that wireless power isn’t quite yet an effortless solution.

The hardware can deliver 5 V at about 1 A wirelessly, which is plenty, but coil alignment is critical to efficiency.

For one thing, the hardware he’s using — similar to those used for mobile phone charging — need the receiver to be very close to the transmitter. In addition, they need to be aligned well or efficiency drops off sharply. For mobile phones this isn’t much of a problem, but it’s difficult to position a Raspberry Pi and display just so when one can’t see the coils. Misalignment means brownouts and other unreliable operation.

So while the wireless power is capable of running the Pi directly, [atomic14] attempts to put a small battery and charger circuit into the mix in order to make the whole thing both portable and more reliable. But because nothing is easy, he discovers that his charging board — which should be able to output as low as 4.5 V — isn’t able to be adjusted down any lower than 5.66 V. It turns out that a resistor marked 104 (which should be 100 kΩ) is actually measuring 57 kΩ, and the trim pot doesn’t go lower than 10 kΩ. The solution is a bit of component swapping, but we suppose it’s a reminder that sometimes with cheap parts, one pays in other ways.

You can see [atomic14]’s wireless power Raspberry Pi running the classic shooter in the video below. Wireless power may have its issues, but it’s certainly a lot less messy than running DOOM with a gigantic potato battery.

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Low-Cost Display Saved By RP2040

April 14, 2023 by 23 Comments

Anyone looking for components for electronics projects, especially robotics, microcontrollers, and IoT devices, has likely heard of Waveshare. They are additionally well-known suppliers of low-cost displays with a wide range of resolutions, sizes, and capabilities, but as [Dmitry Grinberg] found, they’re not all winners. He thought the price on this 2.8-inch display might outweigh its poor design and lack of documentation, and documented his process of bringing it up to a much higher standard with a custom driver for it.

The display is a 320×240 full-color LCD which also has a touchscreen function, but out-of-the-box only provides documentation for sending data to it manually. This makes it slow and, as [Dmitry] puts it, “pure insanity”. His ultimate solution after much poking and prodding was to bit-bang an SPI bus using GPIO on an RP2040 but even this wasn’t as straightforward as it should have been because there are a bunch of other peripherals, like an SD card, which share the bus. Additionally, an interrupt is needed to handle the touchscreen since its default touch system is borderline useless as well, but after everything was neatly stitched together he has a much faster and more versatile driver for this display and is able to fully take advantage of its low price.

For anyone else attracted to the low price of these displays, at least the grunt work is done now if a usable driver is needed to get them up and running. And, if you were curious as to what [Dmitry] is going to use this for, he’s been slowly building up a PalmOS port on hardware he’s assembling himself, and this screen is the perfect size and supports a touch interface. We’ll keep up with that project as it progresses, and for some of [Dmitry]’s other wizardry with esoteric displays make sure to see what he’s done with some inexpensive e-ink displays as well.