Homebrew Reader Brings Paper Tape Programs Back To Life

We may be a bit biased, but the storage media of yesteryear has so much more personality than that of today. Yes, it’s a blessing to have terabyte SD cards smaller than your pinky nail and be able to access its data with mind-boggling speed. But there’s a certain charm to a mass storage device that can potentially slice off your finger.

We’re overstating the dangers of the venerable paper tape reader, of course, a mass storage device that [David Hansel] recreated a few years back but we only just became aware of. That seems a bit strange since we’ve featured his Arduino-based Altair 8800 simulator, which is what this tape reader is connected to. Mechanically, the reader is pretty simple — just a wooden frame to hold the LEGO Technic wheels used as tape reels, and some rollers to guide the tape through a read head. That bit is custom-made and uses a pair of PCBs, one for LEDs and one for phototransistors. There are nine of each — eight data bits plus the index hole — and the boards are sandwiched together to guide the paper tape.

The main board has an ATmega328 which reads the parallel input from the read head and controls the tape motor. That part is important thanks to Altair Basic’s requirement for a 100- to 200-ms delay at the end of each typed line. The tape reader, which is just being used as sort of a keyboard wedge, can “type” a lot faster than that, so the motor speed is varied using PWM control as line length changes.

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Arduino Gear Shift Indicator Finds ‘Em So You Won’t Grind ‘Em

Now, it’s been a shamefully long time since we’ve driven a car with a manual transmission, but as we recall it was pretty straightforward. It certainly didn’t require a lot of help with the shifting pattern, at least not enough to require a technical solution to know what gear you’re in. But then again, we suspect that’s not really the point of [upir]’s latest build.

Oh sure, it’s pretty cool to display your current gear selection on a little LCD screen using an Arduino. And [upir] promises a follow-up project where the display goes inside the shifter knob, which will be really cool. But if you take a look at the video below, you’ll see that the real value of this project is the stepwise approach he takes to create this project. [upir] spends most of the time in the video below simulating the hardware and the code of the project in Wokwi, which lets him make changes and tune the design up before committing anything to actual hardware.

That turned out to be particularly useful with this build since he chose to use analog Hall sensors to detect the shift lever position and didn’t know exactly how that would work. Wokwi let him quickly build a virtual prototype for one sensor (using a potentiometer as a stand-in, since the simulator lacked a Hall sensor model), then quickly expand to the four sensors needed to detect all six gear positions.

By the time his simulation was complete, the code was almost entirely written. [upir] also walks us through his toolchains for both designing the graphics and laying out the PCB, a non-trivial task given the odd layout. We particularly enjoyed the tip on making smooth curved traces around the oval cutout for the shift lever in the board.

The video below is on the longish side, but it’s chock full of great little tips. Check out some more of [upir]’s work, like his pimped-out potentiometer or his custom animations on 16×2 LCDs.

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Car Driving Simulators For Students, Or: When Simulators Make Sense

There are many benefits to learning to fly an airplane, drive a racing car, or operate some complex piece of machinery. Ideally, you’d do so in a perfectly safe environment, even when the instructor decides to flip on a number of disaster options and you find your method of transportation careening towards the ground, or the refinery column you’re monitoring indicating that it’s mere seconds away from going critical and wiping out itself and half the refinery with it.

Still, we send inexperienced drivers in cars onto the roads each day as they either work towards getting their driving license, or have passed their driving exam and are working towards gaining experience. It is this inexperience with dangerous situations and tendency to underestimate them which is among the primary factors why new teenage drivers are much more likely to end up in crashes, with the 16-19 age group having a fatal crash nearly three times as high as drivers aged 20 and up.

After an initial surge in car driving simulators being used for students during the 1950s and 1960s, it now appears that we might see them return in a modern format.

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Learn Sailing Mechanics Without Leaving Dry Land

The ancient art of sailing can be very intimidating for the uninitiated given the shifty nature of wind. To help understand the interaction of wind direction and board orientation, [KifS] designed a hands-on sailing demonstrator that lets students grasp the basics before setting foot on a real sailboat.

The demonstrator uses a potentiometer as a tiller to control a model sailboat’s angle, while another stepper motor adjusts the position of a fan to simulate changing wind directions. With an Arduino Uno controlling everything, this setup affords students the opportunity to learn about sail positioning and adjusting to shifting winds in an interactive way, without the pressures and variables of being on the water.

[KifS]’s creation isn’t just about static demonstrations. It features four modes that progressively challenge learners—from simply getting a feel for the tiller, to adjusting sails with dynamic wind changes, even adding a game element that introduces random wind movements demanding quick adjustments. [KifS] mentions there are potentials aspects that can be refined, like more realistic sail response and usability, but it already achieved the main project goals.

There are a myriad of potential ways to add new tech to the ancient art of sailing. We’ve seen a DIY autopilot system, full sensor arrays, and an open source chart plotter. It’s even been proven you can have a wind powered land vehicle that travels faster than the wind.

Simulating A Time-Keeping Radio Signal

As far as timekeeping goes, there’s nothing more accurate and precise than an atomic clock. Unfortunately, we can’t all have blocks of cesium in our basements, so various agencies around the world have maintained radio stations which, combined with an on-site atomic clock, send out timekeeping signals over the air. In the United States, this is the WWVB station located in Colorado which is generally receivable anywhere in the US but can be hard to hear on the East Coast. That’s why [JonMackey], who lives in northern New Hampshire, built this WWVB simulator.

Normally, clocks built to synchronize with the WWVB station include a small radio antenna to receive the 60 kHz signal and the 1-bit-per-second data transmission which is then decoded and used to update the time shown on the clock. Most of these clocks have internal (but much less precise) timekeeping circuitry to keep themselves going if they lose this signal, but [JonMackey] can go several days without his clocks hearing it. To make up for that he built a small transmitter that generates the proper timekeeping code for his clocks. The system is based on an STM32 which receives its time from GPS and broadcasts it on the correct frequency so that these clocks can get updates.

The small radio transmitter is built using one of the pins on the STM32 using PWM to get its frequency exactly at 60 kHz, which then can have the data modulated onto it. The radiating area is much less than a meter, so this isn’t likely to upset any neighbors, NIST, or the FCC, and the clocks need to be right beside it to update. Part of the reason why range is so limited is that very low frequency (VLF) radios typically require enormous antennas to be useful, so if you want to listen to more than timekeeping standards you’ll need a little bit of gear.

Operate Your Own Nuclear Reactor, Virtually

If you’ve ever wanted to operate your own nuclear reactor, you probably aren’t going to get one in your backyard shop. However, thanks to the University of Manchester, you can get a simulated one in your browser. The pressurized water reactor looks realistic and gives you controls that — we are fairly sure — are greatly simplified compared to the real thing.

We suggest you start with the tour before you start unless, you know, you’ve operated a reactor before. You have to balance the control rods, the coolant pumping, and the steam output to produce as much power as possible without melting the core.

If the reactor were real, the pressure vessel would weigh as much as two 747 jets! Despite the high-tech, the business end is a conventional steam generator. The only difference is that the steam is made by the heat of the nuclear reaction instead of by burning coal or gas.

To operate the reactor, you’ll turn on the coolant pumps and wait for the high-pressure liquid to reach 290 C. In real life, this takes about 8 hours, but lucky for us, the simulation is sped up. Once you reach the right temperature, you can lift the control rods to start generating heat. This will let you adjust the steam output to try to match the demand at any given time. But if you go out of bounds, the reactor will helpfully shut down. Of course, that doesn’t help your score.

We don’t know how realistic it is, but we do know Homer Simpson probably has fewer shutdowns than we do. There are different types of reactors, of course. Operating them may be difficult, but creating fuel for them is no simple task, either. Just maybe put out your candles before you start playing.

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Hackaday Links: September 17, 2023

OK, it’s official — everyone hates San Francisco’s self-driving taxi fleet. Or at least so it seems, if this video of someone vandalizing a Cruise robotaxi is an accurate reflection of the public’s sentiment. We’ve been covering the increasingly fraught relationship between Cruise and San Franciscans for a while now — between their cabs crashing into semis and being used for — ahem — non-transportation purposes, then crashing into fire trucks and eventually having their test fleet cut in half by regulators, Cruise really seems to be taking it on the chin.

And now this video, which shows a wannabe Ninja going ham on a Cruise taxi stopped somewhere on the streets of San Francisco. It has to be said that the vandal doesn’t appear to be doing much damage with what looks like a mason’s hammer; except for the windshield and side glass and the driver-side mirror — superfluous for a self-driving car, one would think — the rest of the roof-mounted lidars and cameras seem to get off lightly. Either Cruise’s mechanical engineering is better than their software engineering, or the neo-Luddite lacks the upper body strength to do any serious damage. Or maybe both.

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