EasyOCR Makes OCR, Well, Easy

July 9, 2020 by 21 Comments

Working on embedded systems used to be easier. You had a microcontroller and maybe a few pieces of analog or digital I/O, and perhaps communications might be a serial port. Today, you have systems with networks and cameras and a host of I/O. Cameras are strange because sometimes you just want an image and sometimes you want to understand the image in some way. If understanding the image involves reading text in the picture, you will want to check out EasyOCR.

The Python library leverages other open source libraries and supports 42 different languages. As the name implies, using it is pretty easy. Here’s the setup:


import easyocr
reader = easyocr.Reader(['th','en'])
reader.readtext('test.jpg')

The results include four points that define the bounding box of each piece of text, the text, and a confidence level. The code takes advantage of the GPU, but you can run it in a CPU-only mode if you prefer. There are a few other options, including setting the algorithm’s scanning behavior, how it handles multiple processors, and how it converts the image to grayscale. The results look impressive.

According to the project’s repository, they incorporated several existing neural network algorithms and conventional algorithms, so if you want to dig into details, there are links provided to both code and white papers. If you need some inspiration for what to do with OCR, maybe this past project will give you some ideas. Or you could cheat at games.

3D Printing A Macro Pad, Switches And All

July 9, 2020 by 15 Comments

Building a macro pad inside of a 3D printed enclosure is hardly news these days. Neither is adding 3D printed keycaps to the mix. But if you go as far as [James Stanley] has, and actually print the switches themselves, we’ve got to admit that’s another story entirely.

Now you might be wondering how [James] managed to print a mechanical keyboard switch that’s the size of your garden variety Cherry. Well, the simple answer is that he didn’t. While his printed switches have the same footprint as traditional switches, they are twice as tall.

The switches could probably made much smaller if it wasn’t for the printed spring, but using a “real” one would defeat the purpose. Though we do wonder if the mechanical design could be simplified by making it an optical switch.

But can printed switches really stand up to daily use? [James] wondered the same thing, so he built a testing rig that would hit the switches and count how many iterations before they stopped working. This testing seems to indicate that the keys will either fail quickly due to some mechanical defect, or last for hundreds of thousands of presses. So assuming you weed out the duds early, you should be in pretty good shape.

Naturally, there are a few bits of copper inside each printed switch to act as the actual contacts. But beyond that, all you need to build one of these printable pads yourself is a USB-HID capable microcontroller like the Arduino Pro Micro. If you used the ESP32, you could even make it Bluetooth.

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Robotic Cornhole Board Does The Electric Slide

July 9, 2020 by 9 Comments

There’s a reason why bowling lanes have bumpers and golf games have mulligans. Whether you’re learning a new game or sport, or have known for years how to play but still stink at it, everyone can use some help chasing that win. You’ve heard of the can’t-miss dart board and no-brick basketball goal. Well, here comes the robot-assisted game for the rest of us: cornhole.

The game itself deceptively simple-looking — just underhand throw a square wrist rest into a hole near the top of a slightly angled box. You even get a point for landing anywhere on the box! Three points if you make it in the cornhole. In practice, the game not that easy, though, especially if you’ve been drinking (and drinking is encouraged). But hey, it’s safer than horseshoes or lawn darts.

[Michael Rechtin] loves the game but isn’t all that great at it, so he built a robotic version that tracks the incoming bag and moves the hole to help catch it. A web cam mounted just behind the hole takes a ton of pictures and analyzes the frames for changes.

The web cam sends the bag positions it sees along with its predictions to an Arduino, which decides how it will move a pair of motors in response. Down in the cornhole there’s a pair of drawer sliders that act as the lid’s x/y gantry.

We love how low-tech this is compared to some of the other ways it could be done, even though it occasionally messes up. That’s okay — it makes the game more interesting that way. We think you should get 2 points if it lands halfway in the hole. Aim past the break to check out the build video.

Seems like there’s a robotic-assisted piece of sporting equipment for everything these days. If cornhole ain’t your thing, how’d you like to take a couple strokes off your golf game?

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Tablet Oscilloscope Claims 100 MHz, But Is It?

July 9, 2020 by 35 Comments

[LearnElectronics] grabbed a FNIRSI tablet oscilloscope from a vendor from China. The device has a seven-inch touchscreen and claims to be a two-channel 100 MHz scope. But is it? Watch the video below and you’ll see.

Spoiler alert: [LearnElectronics] was skeptical of the 100 MHz claim and it looks like it is more like a 30 MHz analog bandwidth. Despite that, it does seem like a pretty capable 30 MHz scope in a very handy form factor and a very cheap price: as little as $120 or so, depending on where you shop.

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Video: Bil Herds Looks At Mitosis

July 9, 2020 by 27 Comments

I loved my science courses when I was in Junior High School; we leaned to make batteries, how molecules combine to form the world we see around us, and basically I got a picture of where we stood in the  scheme of things, though Quarks had yet to be discovered at the time.

In talking with my son I found out that there wasn’t much budget for Science learning materials in his school system like we had back in my day, he had done very little practical hands-on experiments that I remember so fondly. One of those experiments was to look and draw the stages of mitosis as seen under a Microscope. This was amazing to me back in the day, and cemented the wonder of seeing cell division into my memory to this day, much like when I saw the shadow of one of Jupiter’s moons with my own eyes!

Now I have to stop and tell you that I am not normal, or at least was not considered to be a typical young’un growing up near a river in rural Indiana in the 60’s. I had my own microscope; it quite simply was my pride and joy. I had gotten it while I was in the first or second grade as a present and I loved the thing. It was just horrible to use in its later years as lens displaced, the focus rack became looser if that was possible, and dirt accumulated on the internal lens; and yet I loved it and still have it to this day! As I write this, I realize that it’s the oldest thing that I own. (that and the book that came with it).

Today we have better tools and they’re pretty easy to come by. I want to encourage you to do some science with them. (Don’t just look at your solder joints!) Check out the video about seeing mitosis of onion cells through the microscope, then join me below for more on the topic!

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Turning A Waterjet Cutter Into A Wood Lathe, For No Reason

July 9, 2020 by 30 Comments

On the shortlist of dream tools for most metalworkers is a waterjet cutter, a CNC tool that uses insanely high-pressure water mixed with abrasive grit to blast sheet metal into intricate shapes. On exactly nobody’s list is this attachment that turns a waterjet cutter into a lathe, and with good reason, as we’ll see.

This one comes to us by way of the Waterjet Channel, because of course there’s a channel dedicated to waterjet cutting. The idea is a riff on fixtures that allow a waterjet cutter (or a plasma cutter) to be used on tubes and other round stock. This fixture was thrown together from scrap and uses an electric drill to rotate a wood blank between centers on the bed of the waterjet, with the goal of carving a baseball bat by rotating the blank while the waterjet carves out the profile.

The first attempt, using an entirely inappropriate but easily cut blank of cedar, wasn’t great. The force of the water hitting the wood was enough to stall the drill; the remedy was to hog out as much material as possible from the blank before spinning up for the finish cut. That worked well enough to commit to an ash bat blank, which was much harder to cut but still worked well enough to make a decent bat.

Of course it makes zero sense to use a machine tool costing multiple hundreds of thousands of dollars to machine baseball bats, but it was a fun exercise. And it only shows how far we’ve come with lathes since the 18th-century frontier’s foot-powered version of the Queen of the Machine Shop.

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The Simplest TS100 Upgrade Leads Down A Cable Testing Rabbit Hole

July 9, 2020 by 54 Comments

By now, I must have had my Miniware TS100 soldering iron for nearly three years. It redefined what could be expected from the decent end of the budget soldering iron spectrum when it came on the market, and it’s still the one to beat even after those years. Small, lightweight, powerful, and hackable, it has even spawned direct imitations.

If the TS100 has a fault, it comes not from the iron itself but from its cable. A high-grade iron will have an extra-flexible PVC or silicone cable, but the TS100 does not have a cable of its own. Instead it relies on whatever cable comes on its power supply, which is frequently a laptop unit built with portable computing rather than soldering in mind. So to use it is to be constantly battling against its noticable lack of flexibility, a minor worry but one that I find irksome. I determined to find a solution, making a DC extension cable more flexible than that on my power supply. Continue reading “The Simplest TS100 Upgrade Leads Down A Cable Testing Rabbit Hole” →