One aspect of working for Hackaday comes in our regular need to take good quality photographs for publication. I have a semi-decent camera that turns my inept pointing and shooting into passably good images, but sometimes the easiest and quickest way to capture something is to pull out my mobile phone.
It’s a risky step because phone camera modules and lenses are tiny compared to their higher quality cousins, and sometimes the picture that looks good on the phone screen can look awful in a web browser. You quickly learn never to zoom on a mobile phone camera because it’s inevitably a digital zoom that simply delivers grainy interpolated pictures.
That’s not to say that the zoom can’t be useful. Recently I had some unexpected inspiration when using a smartphone camera as a magnifier to read the writing on a chip. I don’t need an archival copy of the image… I just needed a quick magnifying tool. Have I been carrying a capable magnifier for soldering in my pocket or handbag for years without realising it? I decided to give it a try and it worked okay with a few caveats. While I have seen optics turn these cameras into pretty good microscopes, my setup added nothing more than a phone tripod, and will get you by in a pinch.
Continue reading “Using Your Phone As A Microscope On The Electronics Workbench”
Digital video has proceeded to the point at which we have near-broadcast-quality HD production capabilities in the palm of our hand, and often for a surprisingly affordable price. One area in which the benefits haven’t quite made it to our wallets though is in the field of small HD monitors of the type you might place on top of a camera for filming. It’s a problem noted by [Neon Airship], who has come up with a solution allowing the use of an Android mobile phone as an HDMI monitor. Since many of us will now have a perfectly capable older phone gathering dust, it’s an attractive proposition with the potential to cost very little.
The secret isn’t the most elite of hacks in that it uses all off-the-shelf hardware, but sometimes that isn’t the only reason to be interested in a project such as this one. [Neon] is using an HDMI-to-USB capture card of the type that has recently become available from the usual sources for an astoundingly small sum. When paired with a suitable USB OTG cable, the adapter can be seen by the phone as just another webcam.
We see him try a few webcam viewer apps including one that rather worryingly demands a direct APK download, and the result is a very good quality HDMI monitor atop his camera that really didn’t break the bank. Sometimes the simplest of solutions deliver the most useful of results.
This is something of special interest to those of us who experiment with our own camera form factors.
Continue reading “An HDMI Monitor From Your Phone”
As most in the technology community know, nation states have a suite of powerful tools that can be used to trace and monitor mobile phones. By and large, this comes up in discussions of privacy and legislation now and then, before fading out of the public eye once more. In the face of a global pandemic, however, governments are now using these tools in the way many have long feared – for social control. Here’s what’s happening on the ground.
The Current Situation
With COVID-19 sweeping the globe, its high level of contagiousness and rate of hospitalizations has left authorities scrambling to contain the spread. Unprecedented lockdowns have been put in place in an attempt to flatten the curve of new cases to give medical systems the capacity to respond. A key part of this effort is making sure that confirmed cases respect quarantine rules, and isolate themselves to avoid spreading the disease. Rules have also been put in place in several countries where all overseas arrivals must quarantine, regardless of symptoms or status. Continue reading “Cellular Tracking Used During COVID-19 Pandemic”
We think of the mobile phone — well, what we would call a cell phone — as something fairly modern. Many of us can still remember when using a ham radio phone patch from your parked car would have people staring and murmuring. But it turns out in the late 1940s, Bell Telephone offered Mobile Telephone Service (MTS). It was expensive and didn’t work as well as what we have now, but it did let you make or receive calls from your automobile. After the break, you can see a promotional film about MTS.
The service rolled out in St. Louis in the middle of 1946. The 80-pound radios went in the trunk with a remote handset wired to the dashboard. At first, there were only 3 channels but later Bell added 29 more to keep up with demand. An operator connected incoming and outbound calls and if three other people were using their mobile phones, you were out of luck.
Continue reading “Retrotechtacular: Mobile Phones 1940s Style”
Mobile phones are the photography tool for most of us, but they are a blunt tool. If you love astrophotography, you buy a DSLR and a lens adapter. Infrared photography needs camera surgery or a special unit. If you want to look closer to home, you may have a microscope with a CCD. Your pocket computer is not manufactured for microscopy, but that does not mean it cannot be convinced. Most of us have held our lens up to the eyepiece of some binoculars or a microscope, and it sort of works, but it is far from perfect. [Benedict Diederich] and a team are proving that we can get darn beautiful images with a microscope, a phone holder, and some purpose-built software on an Android phone with their cellSTORM.
The trick to getting useful images is to compare a series of pictures and figure out which pixels matter and which ones are noisy. Imagine someone shows you grainy nighttime footage from an outdoor security camera. When you pause, it looks like hot garbage, and you can’t tell the difference between a patio chair and a shrubbery. As it plays, the noisy pixels bounce around, and you figure out you’re looking at a spruce bush, and that is roughly how the software parses out a crisp image. At the cost of frame rate, you get clarity, which is why you need a phone holder. Some of their tests took minutes, so astrophotography might not fare as well.
We love high-resolution pictures of tiny things and that isn’t going to change anytime soon.
Thank you [Dr. Nicolás De Francesco] for the tip.
[Labpacks] wanted to build a robot car controlled by his phone. As a Hackaday reader, of course you probably can imagine building the car. Most could probably even write a phone application to do the control. But do you want to? In most cases, you are better off focusing on what you need to do and using something off the shelf for the parts that you can. In [Labpacks’] case, he used Visuino to avoid writing ordinary code and RemoteXY to handle the smartphone interface.
RemoteXY is a website that allows you to easily build a phone interface that will talk to your hardware over Bluetooth LE, USB, or Ethernet (including WiFi). One thing of interest: even though the interface builder is Web-based, the service claims that the interface structure stays on the controller. There’s no interaction with the remote servers when operating the user interface so there is no need for an external Internet connection.
Continue reading “RemoteXY Simplifies Arduino Control”
It’s no secret that the average smart phone today packs an abundance of gadgets fitting in your pocket, which could have easily filled a car trunk a few decades ago. We like to think about video cameras, music playing equipment, and maybe even telephones here, but let’s not ignore the amount of measurement equipment we also carry around in form of tiny sensors nowadays. How to use those sensors for educational purposes to teach physics is presented in [Sebastian Staacks]’ talk at 36C3 about the phyphox mobile lab app.
While accessing a mobile device’s sensor data is usually quite straightforwardly done through some API calls, the phyphox app is not only a shortcut to nicely graph all the available sensor data on the screen, it also exports the data for additional visualization and processing later on. An accompanying experiment editor allows to define custom experiments from data capture to analysis that are stored in an XML-based file format and possible to share through QR codes.
Aside from demonstrating the app itself, if you ever wondered how sensors like the accelerometer, magnetometer, or barometric pressure sensor inside your phone actually work, and which one of them you can use to detect toilet flushing on an airplane and measure elevator velocity, and how to verify your HDD spins correctly, you will enjoy the talk. If you just want a good base for playing around with sensor data yourself, it’s all open source and available on GitHub for both Android and iOS.
Continue reading “36C3: Phyphox – Using Smartphone Sensors For Physics Experiments”