Very few people want to invent the universe before they blink their first LED. Sure, with enough interest a lot of folks will drill-down to the atomic level of technology and build their way back up. But there’s something magical about that first time you got your blinky to blink, and knowing how to write makefiles plays no part in that experienc). Now apply that to projects using smartphone as wireless interfaces… how simple can we make it for people?
Jose David Cuartas is working to answer that very question and gives us a guided tour of his progress in this Meta_Processing workshop held during the Hackaday Remoticon. Meta-Processing is an IDE based on — as you’ve probably guessed — Processing, the programming language that unlocked higher-level functionality to anyone who wanted to perform visually-interesting things without becoming software zen masters. The “Meta_” part here is that it can now be done with very limited typing and interchangeably between different spoken languages.
The approach is to take the best of text programming and block programming languages and mash them together. In that way, you don’t type new lines, you add them with a click of the mouse and select the instruction you want to use on that line from a list. It means you don’t need to have the instructions memorized, and avoids typos in your code. The docs for that instruction will be shown on the bottom bar of the IDE to help you with parameters. And the kicker is that since you’re selecting the instructions, choosing any of the IDE’s 14 available spoken languages will update your “code” with translations into the new language.
People learn in many different ways. Having options like this to help people get to blinky very quickly is a great way to break down barriers to understanding and using computers.
One of the side effects of the rise of 3D printers has been the increased availability and low cost of 3D printer components, which are use fill for range of applications. [How To Mechatronics] capitalized on this and built a SCARA robot arm using 3D-printed parts and common 3D-printer components.
The basic SCARA mechanism is a two-link arm, similar to a human arm. The end of the second joint can move through the XY-plane by rotating at the base and elbow of the mechanism. [How To Mechatronics] added Z-motion by moving the base of the first arm on four vertical linear rods with a lead screw. A combination of thrust bearings and ball bearings allow for smooth rotation of each of the joints, which are belt-driven with NEMA17 stepper motors. Each joint has a microswitch at a certain position in its rotation to give it a home position. The jaws of the gripper slide on two parallel linear rods, and are actuated with a servo. For controlling the motors, an Arduino Uno and CNC stepper shield was used.
The arm is operated from a computer with a GUI written in Processing, which sends instructions to the Arduino over serial. The GUI allows for both direct forward kinematic control of the joints, and inverse kinematic control, which will automatically move the gripper to a specified coordinate. The GUI can also save positions, and then string them together to do complete tasks autonomously.
The base joint is a bit wobbly due to the weight of the rest of the arm, but this could be fixed by using a frame to support it at the top as well. We really like the fact that commonly available components were used, and the link in the first paragraph has detailed instructions and source files for building your own. If the remaining backlash can be solved, it could be a decent light duty CNC platform, especially with the small footprint and large travel area. Continue reading “3D Printed SCARA Arm With 3D Printer Components”→
One of the disadvantages of having cheap WiFi-capable boards like those based on the ESP32 is that you have to update them. If you have even a few in every room of your house, it can be a pain to pull them out and connect them to a cable for programming. Over the air programming is a great answer, and [Kevin] shows how you can control the update via a simple GUI. You can see a video demonstration of how it works below.
[Kevin] uses a ready-made OTA library to do the work, but creates a GUI configuration and downloader tool. There is a manual step to force the board into the OTA mode, which might be a mild inconvenience, but it improves security since you need physical access to the device to do an update.
A lot of consumer gadgets use touch sensors now. It is a cheap and reliable way to replace a variety of knobs and switches on everything from headphones to automobiles. However, creating a custom touch controller for a one-off project can be daunting. A recent ACM paper shows how just about any capacitive sensor can work as a multitouch sensor with nothing more than an Arduino although a PC running processing interprets the data for higher-level functions.
The key is that the Arduino excites the grid using PWM and then examines the signal coming out of the grid. Finger poking changes the response quite a bit and the Arduino can sense it using the analog to digital converters onboard. You can find the actual software kit online. The tutorial document is probably more interesting than the ACM paper if you only want to use the kit.
The optimum drive frequency is 10 MHz. The examples rely on harmonics of a lower frequency PWM signal to get there. The analog conversion, of course, isn’t that fast but since your finger touch rate is relatively slow, they treat the signal as an amplitude-modulated input which is very easy to decode.
The sensors can be conductive ink, thread, or copper strips. There are several example applications, including a 3D printed bunny you can pet, a control panel on a sleeve, and an interactive greeting card.
The sensor forms an image and OpenCV detects the actual touch configuration. It appears you can use the raw data from the Arduino, too, but it might be a little harder.
Making a natural fiber like wool into something useful like a sweater involves a lot of steps. We might be familiar with shearing the sheep, spinning the wool into yarn, or knitting and weaving, but between shearing and spinning there’s another unfamiliar process you’ll have to go through. Known as carding, it helps align the fibers so they are able to be spun, and of course it requires either an expensive tool, or one you build on your own.
This drum carder is exactly what it sounds like. It uses two drums covered in a metal mesh, spinning at different speeds, which pull the fibers into an orderly shape. Small drum carders like this can run around $600 but with some quality wood and a lathe you can easily make one for a fraction. Making the series of drums is fairly straightforward with a lathe, and from there you need to make sure they are connected with a quality belt or chain and then covered in the appropriate metal mesh.
[kris] notes in the reddit comments section that he’d like for a second version to spin a little faster and be a little more durable, but this is a great working carder nonetheless. From there you’ll want to move on to spinning the wool into yarn, which you can do with either a wheel or an electric motor.
All the cool projects now can connect to a computer or phone for control, right? But it is a pain to create an app to run on different platforms to talk to your project. [Kevin Darrah] says no and shows how you can use Google Chrome to do the dirty work. He takes a garden-variety Arduino and a cheap Bluetooth interface board and then controls it from Chrome. You can see the video below.
The HM-10 board is cheap and could connect to nearly anything. The control application uses Processing, which is the software the Arduino system derives from. So how do you get to Chrome from Processing? Easy. The p5.js library allows Processing to work from within Chrome. There’s also a Bluetooth BLE library for P5.
Fadecandy is a platform specifically designed to drive WS2812B LEDs for artistic purposes. This allows users to focus on the visual side of things without getting bogged down with the hassle of selecting the right microcontroller and choosing the applicable libraries. It works great in combination with Processing, a piece of software designed for coders experimenting with visual arts. Through a USB link, any graphics drawn by processing can be mapped to the LEDs attached to the Fadecandy controller.
[Amy] does a great job of explaining how to do everything required, from purchasing the right equipment, through wiring everything up, and then getting it all humming along with the correct software. If you’ve ever wanted to build a big flashy project with a ton of LEDs, this would be a great place to start.