Automatic Transfer Switch Keeps Internet Online

July 31, 2023 by 48 Comments

Living in a place where the electric service isn’t particularly reliable can be frustrating, whether that’s because of a lack of infrastructure, frequent storms, or rolling blackouts. An option for those living in these situations is a backup generator, often turned on and connected by an automatic transfer switch. These are necessary safety devices too; they keep power lines from being back-fed by the generators. But there are other reasons to use transfer switches as well as [Maarten] shows us with this automatic transfer switch meant to keep his computers and Internet powered up.

The device is fairly straightforward. A dual-pole, dual-throw relay is housed inside of an electrical junction box with two electrical plugs, each of which can be connected to a different circuit or power source in [Maarten]’s house. The relay coil is energized by the primary power supply, and when that power is lost the relay automatically changes over to the other power supply, which might be something like a battery backup system. [Maarten] was able to get a higher quality product by building it himself rather than spending a comparable amount of money on a cheap off-the-shelf product as well. Continue reading “Automatic Transfer Switch Keeps Internet Online” →

TinyBasicLike: A Target-Independent BASIC Interpreter

July 31, 2023 by 13 Comments

In the long and winding history of BASIC, it’s sometimes hard to keep track of all the different variants and dialects. Some may still remember TinyBASIC, which was published in 1976 as Palo Alto Tiny BASIC by [Gordon Brandly]. Later, TinyBASIC was modified by a number of people including [Scott Lawrence] who created TinyBASIC Plus (TBP). Inspired by this, [Karl] figured he could improve on TBP by making the original C-based project even easier to port by removing whatever platform dependencies he could find, creating what he calls TinyBasicLike.

The main change is that TinyBasicLike consists out of two C files, with one containing the core code, and the second the platform-specific details that can be used by the core. Although [Karl] started off with the Palo Alto Tiny BASIC-like code by [Scott Lawrence], he decided to make it into his own by making a few alterations, such as adding left and right shift operators, adding an ADDR() function, expanding the features of INPUT and adding multiple logical operators.

In the example STM32F4 project linked on the project page it is demonstrated how to target a new platform with TinyBasicLike. Performance on the STM32F4 Discovery board with a simple counting loop yielded about 6 lines of TBL program code per millisecond. For a 168 MHz STM32 MCU that’s definitely not astounding, but considering how straightforward Tiny BASIC (and TBL as a consequence) is, it’s definitely no slouch.

This is probably a good time to remind that BASIC was the original champion of cross-platform programming and the source of countless fond (and frustrating) memories.

A New Educational Robotics Platform

July 30, 2023 by 10 Comments

When looking for electronics projects to use in educational settings, there is no shortage of simple, lightweight, and easily-accessible systems to choose from. From robotic arms, drones, walking robots, and wheeled robots, there is a vast array of options. But as technology marches on, the robotics platforms need to keep up as well. This turtle-style wheeled robot called the Trundlebot uses the latest in affordable microcontrollers on a relatively simple, expandable platform for the most up-to-date educational experience.

The robot is built around a Raspberry Pi Pico, with two low-cost stepper motors to drive the wheeled platform. The chassis can be built out of any material that can be cut in a laser cutter, but for anyone without this sort of tool it is also fairly easy to cut the shapes out by hand. The robot’s functionality can be controlled through Python code, and it is compatible with the WizFi360-EVB-Pico which allows it to be remote controlled through a web application. The web interface allows easy programming of commands for the Trundlebot, including a drag-and-drop feature for controlling the robot.

With all of these features, wireless connectivity, and a modern microcontroller at the core, it is an excellent platform for educational robotics. From here it wouldn’t be too hard to develop line-follower robots, obstacle-avoiding robots, or maze-solving robots. Other components can easily be installed to facilitate these designs as well. If you’re looking for a different style robot, although not expressly for educational purposes this robotic arm can be produced for under $60.

An Open-Source, Free Circuit Simulator

July 30, 2023 by 60 Comments

The original circuit simulation software, called the Simulation Program with Integrated Circuit Emphasis, or SPICE as it is more commonly known, was originally developed at the University of Califorina Berkeley in the 1970s with an open-source license. That’s the reason for the vast versions of SPICE available now decades after the original was released, not all of which are as open or free as we might like. Qucs is a GPL circuit simulator. And if you want the GUI option, you might want to try out QucsStudio, which uses Qucs under the hood, and is free to use, but binary-only.

(Editor’s note: the author was confused between the GPL open-source Qucs and the closed-source, binary-only QucsStudio. We’ve cleaned that up.)

QucsStudio supports a wide range of circuit components and models much in the same fashion as other more popular SPICE programs, including semiconductor devices, passive components, and digital logic gates. Qucs also utilizes SPICE-based simulation, which can model various types of circuit behavior, such as DC, AC, transient, and small-signal analysis.

Unfortunately there are only Windows versions available, and although some might have some success running it under WINE. There are plenty of other options for those of us running non-Windows operating systems though. Here’s a review of 30 of them.

Thanks to [Electroagenda] for the tip!

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Hackaday Links: July 30, 2023

July 30, 2023 by 14 Comments

A couple of weeks ago, we noted with interest that the space shuttle Endeavour (OV85) would be set up as a full-stack launch configuration display, complete with external fuel tank and solid rocket boosters. We predicted that this would result in some interesting engineering, not least of which will be making the entire 20-story stack safe from seismic activity. Looks like we were right on all counts, with this story about the foundation upon which the display will stand, which has been under construction for quite a while now. The base has six seismic isolators that support the 2.4-m thick slab of reinforced concrete that will serve as a perch for the full stack. The 1,800-ton slab will be able to move a meter or so from its resting position during earthquakes. Or perhaps more accurately, the foundation will allow Los Angeles to move as much as it wants while Endeavour rides it out.

If like us you’re worried that seismic loads are vastly different than the loads the spacecraft was actually designed for, relax — it turns out that the flight loads are far in excess of predicted loads from seismic stress. The plan is to build the booster stacks first — the aft skirts, which will support the entire stack, were just bolted in place — then lift the external tank in place between the boosters, and finally hoist the actual orbiter into place. After the stack is complete, the rest of the building will be built around it. We’re really looking forward to seeing some video on this project.

Continue reading “Hackaday Links: July 30, 2023” →

Turning A Window Air Conditioning Unit Into Whole-House AC

July 30, 2023 by 109 Comments

Although air conditioning units are generally subdivided into a number of categories, including window, split and whole house/building units, they still work the same, with the compressor, condenser and expansion stages.

Extending the wiring for the AC unit’s controller board (Credit: HowToLou)

In the case of widely available window AC units you can indeed use them as designed in a window, or as [HowToLou] is in the process of demonstrating, as a whole-house AC unit. The main thing to keep an eye out for here is the rated capacity of the window AC unit (in British Thermal Units, square meters/feet). In this case [Lou] used a pretty beefy $600, 24,000 BTU window unit that should be good for about 1200 sqf (~111 m2) .

Most of the modifications are pretty straightforward, with the control board needing to have its wiring extended, as well as the AC unit’s air intake and exhaust on the indoors side. The unit is then placed outside on a stable foundation and inserted into a suitably sized hole in the side of the building, with the controller’s cable running to it from indoors. For the next step, [Lou] intends to connect the air channels on the AC unit to the house’s furnace ducts, to complete the whole-house AC installation.

Compared to a regular whole-house AC unit, this DIY approach has the advantage of anyone being able to just buy and install a window AC unit, whereas whole-house AC tends to require a licensed installer and a lot of additional costs. How well [Lou]’s DIY approach ends up working will hopefully be revealed in a Part 2.

Continue reading “Turning A Window Air Conditioning Unit Into Whole-House AC” →

The British Government Is Coming For Your Privacy

July 30, 2023 by 77 Comments

The list of bad legislation relating to the topic of encryption and privacy is long and inglorious. Usually, these legislative stinkers only affect those unfortunate enough to live in the country that passed them. Still, one upcoming law from the British government should have us all concerned. The Online Safety Bill started as the usual think-of-the-children stuff, but as the EFF notes, some of its proposed powers have the potential to undermine encryption worldwide.

At issue is the proposal that services with strong encryption incorporate government-sanctioned backdoors to give the spooks free rein to snoop on communications. We imagine that this will be of significant interest to some of the world’s less savoury regimes, a club we can’t honestly say the current UK government doesn’t seem hell-bent on joining. The Bill has had a tumultuous passage through the Lords, the UK upper house, but PM Rishi Sunak’s administration has proved unbending.

If there’s a silver lining to this legislative train wreck, it’s that many of the global tech companies are likely to pull their products from the UK market rather than comply. We understand that UK lawmakers are partial to encrypted online messaging platforms. Thus, there will be poetic justice in their voting once more for a disastrous bill with the unintended consequence of taking away something they rely on.

Header image: DaniKauf, CC BY-SA 3.0.