Using A Smartphone As A Touchscreen For Arduino

December 16, 2024 by Lewin Day 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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Microfluidic Motors Could Work Really Well For Tiny Scale Tasks

November 14, 2024 by Lewin Day 8 Comments

The vast majority of motors that we care about all stick to a theme. They rely on the electromagnetic dance between electrons and magnets to create motion. They come in all shapes and sizes and types, but fundamentally, they all rely on electromagnetic principles at heart.

And yet! This is not the only way to create a motor. Electrostatic motors exist, for example, only they’re not very good because electrostatic forces are so weak by comparison. Only, a game-changing motor technology might have found a way to leverage them for more performance. It achieves this by working with fluid physics on a very small scale.

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Reusing An Old Android Phone For GPIO With External USB Devices

November 4, 2024 by Maya Posch 44 Comments

Each year millions of old smartphones are either tossed as e-waste or are condemned to lie unloved in dusty drawers, despite the hardware in them usually being still perfectly fine. Reusing these little computers for another purpose once the phone’s manufacturer drops support is made hard by a range of hardware and software (driver) issues. One possible way to do so is suggested by [Doctor Volt] in a video where a Samsung Galaxy S4 is combined with a USB-connected FT232R board to add external GPIO.

The idea is pretty simple: the serial adapter is recognized by the existing Android OS and within the standard Android development environment this module can be used. Within this demonstrator it’s merely used to blink some LEDs and react to inputs, but it shows how to reuse one of these phones in a non-destructive manner. Even better is that the phone’s existing sensors and cameras can still be used as normal in this way, too, which opens a whole range of (cheap) DIY projects that can be programmed either in Java/Kotlin or in C or C++ via the Native Development Kit.

The only wrinkle is that while the phone is connected like this, charging is not possible. For the S4 it’s easy to solve as it has a removable battery, so an external power input was wired in with a dummy battery-sized bit of perfboard. With modern phones without removable batteries simultaneous USB/audio dongle and charging usage via the USB-C connector is claimed to be possible, but this is something to check beforehand.

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Easily Program RP2040 Boards With Your Android Device

October 11, 2024 by Lewin Day 8 Comments

You could write your microcontroller code on your desktop PC, or you could do it on your laptop on the go. Or, if you want to get really portable about things, you could write your embedded code on your phone. Enter DroidScript.

Basically, DroidScript is a JavaScript and Python IDE for Android phones and tablets. Simple enough. You can use it to write apps for your phone or tablet. But its party piece? You can now also use it to program for embedded devices—namely, a range of those based on the RP2040 microcontroller. For example, the Adafruit QT-Py RP2040, the Pimoroni TinyFX, or the Pimoroni Yukon. They run MicroPython and CircuitPython, and you can program them from DroidScript. Easy.

A decade ago, this would have been a royal pain in the butt. But today? It’s easy, because the smartphones and devboards both use USB-C connectors. All you need is a regular USB-C cable and you can hook straight up to the board and burn your code.

You can get the app on the Google Play Store if you’re so inclined. We’ve seen some other neat smartphone programming projects over the years, too. Meanwhile, if you’ve found any other nifty ways to get your code on to a dev board, don’t hesitate to let us know!

Lindroid Promises True Linux On Android

June 18, 2024 by Al Williams 16 Comments

Since Android uses Linux, you’d think it would be easier to run Linux apps on your Android phone or tablet. There are some solutions out there, but the experience is usually less than stellar. A new player, Lindroid, claims to provide real Linux distributions with hardware-accelerated Wayland on phones. How capable is it? The suggested window manager is KDE’s KWIN. That software is fairly difficult to run on anything but a full-blown system with dbus, hardware accelerations, and similar features.

There are, however, a few problems. First, you need a rooted phone, which isn’t totally surprising. Second, there are no clear instructions yet about how to install the software. The bulk of the information available is on an X thread. You can go about 4 hours into the very long video below to see a slide presentation about Lindroid.

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The Moondrop MIAD 01: A Smartphone With Balanced Audio Output

May 9, 2024 by Maya Posch 21 Comments

Over the past several years we have seen smartphones regrettably lose features which were once standard, such as FM radios, IR blasters, status LEDs, physical buttons, micro SD card slots, and of course headphone jacks. An interesting counterpoint here regarding the latter is the newly released Moondrop MIAD 01 smartphone.

As a relatively well-known manufacturer of audio equipment including in-ear monitors (IEMs), the announcement of a smartphone came out of left field, but the specifications make sense. Of particular interest are the dual audio jacks: one 3.5 mm TRRS and one 4.4 mm balanced TRRS, making it a good match for high-end headphones that support balanced audio.

While the smartphone hardware is your average mid-range selection, featuring a MediaTek Dimensity 7050 SoC — its main selling point are the dual Cirrus Logic MasterHiFi DACs, that power the dual audio jacks. It’s also the reason behind the name: Mobile Internet Audio Device, or MIAD for short.

Given Moondrop’s audio enthusiast market, this tracks. These are people for whom the mere mentioning of ‘Bluetooth Audio’ or ‘USB-C-to-audio jack dongle’ is likely to evoke a less than favorable response.

In terms of software, Moondrop says the phone will offer a “native” Android 13 experience, which hopefully means it will be free from manufacturer-specific changes and bloatware. You’ll need to manually install Google Mobile Services though, as is often the case with Android devices that aren’t from the major players in the industry.

As reported by Android Authority, the MIAD 01 is available via select outlets for $399. Details like software updates remain to be clarified, but this might be the most over the top audio-centric smartphone we have seen so far. It definitely gives Sony’s current range of Android-based Walkmans a run for their money, while even having phone functionality in the package.

Android-Powered Rigol Scopes Go Wireless

January 18, 2024 by Al Williams 9 Comments

The Rigol DHO800 and DHO900 series use Android underneath, and as you might expect, this makes them easier to hack. A case in point: [VoltLog] demonstrates that you can add WiFi to the scope using a cheap USB WiFi adapter. This might seem like a no-brainer on the surface, but because the software doesn’t know about WiFi, there are a few minor hoops to jump through.

The first issue is that you need a WiFi adapter the built-in OS already knows how to handle. The community has identified at least one RTL chipset that works and it happens to be in the TP-Link TL-WN725N. These are old 2.4 GHz only units, so they are widely available for $10 or less.

But even with the correct hardware, the scope doesn’t have any menus to configure the WiFi interface. To solve that, you need to temporarily use a USB hub and a USB keyboard. Once you have everything plugged in, you can use the Super + N keyboard shortcut to open up the Android notification bar, which is normally hidden. Once you’ve setup the network connection, you won’t need the keyboard anymore.

Or maybe not — it turns out the keyboard does allow you to change a few other things. For example, [VoltLog] used it to increase the screen brightness more than the default maximum setting.

The only other issue appears to be that the scope shows it is disconnected even when connected to WiFi. That doesn’t seem to impact operation, though. Of course, you could use a WiFi to Ethernet bridge or even an old router, but now you have a cable, a box, and another power cord to deal with. This solution is neat and clean. You bet we’ve already ordered a TP-Link adapter!

WiFi scopes are nothing new. We suspect Rigol didn’t want to worry about interference and regulatory acceptance, but who knows? Besides, it is fun to add WiFi to wired devices.

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