Kritik sah

Measuring electric currents is an essential element of many electrical systems, but doing so in a way that is as nonintrusive as possible is not an easy problem to solve. Due to this we got a wide variety of current sensors to choose from for any given application, with [ElectrArc240] running us through these variants in a recent video. The fairly low-tech, cheap and quite reliable method of using a shunt resistor is first demonstrated. This sees a lot of use in fairly low-voltage and low-current applications, with for example videocards using it to limit the amount of power the GPU can use, a feature that modders will happily bypass. Here simply the voltage drop across a known resistance value is measured, from which the current can be derived. Of course, you got higher voltage and higher current applications too, as well as direct- and alternating current, with the latter especially allowing for easy current measurements simply from the electromagnetic field, or flux. Anyone who h...

The Philips CD-i was not popular upon its launch in 1991, and is barely acknowledged today. In the opinion of [MattKC], it had a particularly poor selection of controllers, too, and it’s often hard to find used examples anyway. To rectify this situation, he whipped up an adapter to let him use Sega Genesis controllers instead. The benefit of the Genesis controller is that it uses DB-9 connectors that are readily available, and it’s got a simple pinout that is compatible with the Atari joystick port, too. It makes interfacing the controllers supremely easy. Converting the controllers required using a Arduino Pro Micro to read the Genesis pad and translate it into something suitable for the CD-i. On the Sega controller side, the microcontroller just has to strobe one pin while reading the state of others to determine what all the buttons are doing. The CD-i, however, expects a serial data stream from the original Philips controllers. Thus, the microcontroller is set up to po...

We don’t generally think of 3D printing and knitting in the same sentence. One uses threads and fine motor control, while the other requires great knowledge of pressing buttons and plastics. That said, they both entail stacking material over and over until a finished product emerges. So why not blend the two crafts together? [Joram de Haas] decided to work on just that in the form of FilaLoom . 2D, 3D, and even embedded mechanisms! This isn’t the first time we have seen additional elements embedded into 3D printed parts here on Hackaday. However, this particular implementation has some extra features which allow the embedded structures to grow larger than most examples prior. Instead of placing any implements directly into a structure by hand, all thread is placed by a tool head not so different from tool-changer printers. Using both the 3D printing tool head and the thread tool, some truly interesting properties can emerge from the finished product. If you aren’t interested in...

Although we generally do not look at bubbles in fluids as more than a curiosity – if not an outright annoyance – in certain contexts they can be very useful. If you can namely control their formation and position, you can use them in small systems to control actuators and dynamically affect acoustic systems. The main issues here are that controlling their formation, lifetime and controllability remain hard to solve. This is what [Zhiyuan Zhang] et al. sought to address, with a recent study published in  Science Advances covering their approach using ultrasound-driven, electronically programmable microbubbles. There’s also a Cornell press release article about their findings, which uses a new device that produces hydrogen bubbles along a grid of electrodes, before using ultrasound to steer them around. Using this chip-like device they claim to be able to control the 10-100 micron sized bubbles, with the ultrasound matching the resonant frequency of the target bubble...

If you have developed in Pascal or Delphi in the past decades, you’re probably familiar with the Lazarus IDE that provides an interface to the Free Pascal Compiler (FPC), much like Delphi’s IDE. For users of Lazarus IDE there’s now an exciting new development, with the announcement that FPC and Lazarus now support dynamic packages . The upshot of this is that you no longer need to rebuild the IDE if you want to add components, controls and Lazarus extensions. In addition you can use this same dynamic package feature in your own Pascal applications this way. Naturally this is a great improvement, and it’s good to see more improvements to such a venerable programming language. Not only is it still being used today for just about anything, including web development , but there is a good case to be made for using Pascal today as it’s no longer the language it was half a decade ago. We’d also be remiss to not mention the legacy of [Niklaus Wirth] , who...

When most radio enthusiasts start trying to pick up signals from satellites, they might put together a quick-and-dirty Yagi antenna and try to catch a repeater as is passes overhead, or they might grab a small unused dish from a satellite TV service and point it up at a weather satellite by hand to try to decode some of the data coming down. But [Cranktown City] had a different approach. He found an eight-foot dish online and built a massive articulating base station out of it as his first exploration into the world of satellites. The first problem that needs to be solved with a dish of this size is its mounting location. This installation uses a large post and concrete foundation with a custom-fabricated metal base at the bottom. The metal base houses all of the electronics not just for receiving signals from the dish, but also for orienting it properly. That includes a large metal gear driven by a wheelchair motor to control its azimuth and a linear actuator to take care of its ele...