Author: Al Williams

4424 Articles

Driving A Motor With An Audio Amp Chip

September 18, 2023 by 25 Comments

[InazumaDenki] wanted to answer the question: can you drive a motor with an audio amplifier chip? The answer, of course, is yes. The TDA7052 has a single input, and a bridge output meant to drive a speaker differentially. It should work if the motor doesn’t present more of a load than a speaker.

The plan was to use a resistive divider to provide several discrete voltages to the input. At precisely the half-way mark, there should be no voltage across the load. Altering the input to go higher than halfway should make the motor turn one way, and making it go lower should turn the motor the other way. As you can see in the video below, it does work, although it may not be ideal for this application.

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3D Printing At 100C

September 17, 2023 by 23 Comments

Normally, 3D printing with filament takes temperatures of around 200 °C. However, there are some crafting plastics that melt in hot water at 60 °C. You can get spools of similar plastic that prints at very low temperatures, and some 3D printing pens use it. [Lost in Tech] picked up a spool of the stuff meant for medical printing and found that printing with it was a challenge. You can watch a video of the results below.

The first problem is that most printers don’t want to extrude at low temperatures. You can override this or, if you want to print with this plastic — PCL — you can rebuild the printer firmware. He never got bridges to work very well, but some prints came out reasonably well.

Of course, you might wonder why you would care about this kind of plastic. For one thing, it’s apparently safe to work with. If you were printing with students, too, you might be interested in a lower printer temperature. However, it didn’t look like the results were that good. However, it makes you wonder what kinds of filament you could use with a little work that might have some benefit.

The last time we heard about this stuff, someone was printing bones with it. We are always on the lookout for oddball filament to play with.

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The End Of Basic?

September 17, 2023 by 101 Comments

Many people, one way or another, got started programming computers using some kind of Basic. The language was developed at Dartmouth specifically so people could write simple programs without much training. However, Basic found roots in small computers and grew to where it is today, virtually unrecognizable. Writing things in something like Visual Basic may be easier than some programming tasks, but it requires a lot of tools and some reading or training. We aren’t sure where the name EndBasic came from, but this program — written in Rust — aims to bring Basic back to a simpler time. Sort of.

You can run the program in a browser, locally, or connected to a cloud service. It looks like old-fashioned Basic at first. But the more you dig in, the odder it gets. The command line is more akin to a Python REPL. You type things, and they happen. It took a while to figure out that you need to enter EDIT to write a program. Then, what you type gets saved until you press escape. The syntax is Basic-like but has oddities. There are no line numbers, but you can use labels that start with an at sign.

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This Arduino Debugger Uses The CH552

September 11, 2023 by 16 Comments

One of the things missing from the “classic” Arduino experience is debugging. That’s a shame, too, because the chips used have that capability. However, the latest IDE has the ability to work with external debuggers and if you want to get started with a classic ATMega Arduino, [deqing] shows you how to get started with a cheap CH552 8-bit USB microcontroller board as the debugging dongle.

The CH552 board in question is a good choice, primarily because it is dirt cheap. There are design files on GitHub (and the firmware), but you could probably pull the same trick with any of the available CH552 breakout boards.

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Cheap LCD Uses USB Serial

September 11, 2023 by 20 Comments

Browsing the Asian marketplaces online is always an experience. Sometimes, you see things at ridiculously low prices. Other times, you see things and wonder who is buying them and why — a shrimp pillow? But sometimes, you see something that probably could have a more useful purpose than the proposed use case.

That’s the case with the glut of “smart displays” you can find at very low prices. Ostensibly, these are being sold as system monitors. A business-card-sized LCD hooks up via USB and shows your CPU speed, temperature, and so on. Of course, this requires sketchy Windows software. I don’t run Windows, and if I did, I wouldn’t be keen to put some strange service on just so I could see tiny displays of my system information. But a 3.5-inch IPS LCD screen for $15 or less probably has some other uses. But how to drive it? Turns out, it is easier than you think and the hardware looks reasonably hackable, too.

Like a lot of this cheap stuff, these screens are sold under a variety of names, and apparently, there are some subtle differences. Two of the main makers of these screens are Turing and XuanFang, although you rarely see those names in the online listings. As you might expect, though, someone has reverse-engineered the protocol, and there is Python software that will replace the stock Windows software the devices use. Even better, there is an example of using the library for your own purposes.

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Balloon-Eye View Via Ham Radio

September 11, 2023 by 22 Comments

If you’ve ever thought about launching a high-altitude balloon, there’s much to consider. One of the things is how do you stream video down so that you — and others — can enjoy the fruits of your labor? You’ll find advice on that and more in a recent post from [scd31]. You’ll at least enjoy the real-time video recorded from the launch that you can see below.

The video is encoded with a Raspberry Pi 4 using H264. The MPEG-TS stream feeds down using 70 cm ham radio gear. If you are interested in this sort of thing, software, including flight and ground code, is on the Internet. There is software for the Pi, an STM32, plus the packages you’ll need for the ground side.

We love high-altitude balloons here at Hackaday. San Francisco High Altitude Ballooning (SF-HAB) launched a pair during last year’s Supercon, which attendees were able to track online. We don’t suggest you try to put a crew onboard, but there’s a long and dangerous history of people who did.

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Bringing Da Vinci’s Saw Mill To Life

September 11, 2023 by 30 Comments

DaVinci’s notebook — the real one, not the band — was full of wonderous inventions, though many were not actually built and probably weren’t even practical with the materials available at the time (or even now). [How To Make Everything] took one of the Master’s drawings from 1478 of a sawmill and tried to replicate it. How did he do? You can see for yourself in the video below.

There are five different pieces involved. A support structure holds a water wheel and a saw. There’s a crank mechanism to drive the saw and a sled to move the wood through the machine. It sounds simple enough, although we were impressed and amused that he made his own nails to be authentic. No Home Depot back in the 1470s, after all.

Watching him produce, for example, castle joints, makes us think, “Hey, we could do that!” But, of course, we probably can’t, at least not by hand. We must admit we are pretty dependent on CNC tools and 3D printing, but we admire the woodwork, nevertheless. There’s some pretty cool metal working, too.

We thought the waterwheel would be the easy part, but it turned out to be a bit of a problem. Things worked, but it was slower than you would think. We’ve seen sawmills put together before. Da Vinci worked for money, and there was always money in weapons so he did design a lot of them, too.

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