Simple CNC Gear Production With Arduino

October 10, 2022 by Al Williams 21 Comments

We’ve seen plenty of people 3D printing custom gears over the years, but [Mr Innovative] decided against an additive process for his bespoke component. He ended up using a simple CNC machine that makes use of several components that were either salvaged from a 3D printer or produced on one. Using a small saw blade, the machine cuts gear teeth into some plastic material and — presumably — could cut gears into anything the saw blade was able to slice into, especially if you added a little lubrication, cooling, and dust removal.

If you’ve built a 3D printer, you’ll see a lot of familiar parts. Stepper motors, aluminum extrusion, straight rods, bearing blocks, and rod holders are all used in the build. There’s also a lead screw and the associated components you usually see in a printer’s Z-axis. Naturally, an Arduino drives the whole affair.

The saw blade was custom-made from a washer, grinding an edge and using a 3D printed template to cut teeth in it. We might have been more inclined to use a cut-off wheel from a rotary tool, but this certainly did the trick. An LCD accepts the gear diameter and number of teeth. The stepper rotates the correct number of degrees and another stepper lowers the cutting head which is spinning with a common DC motor.

As impressive as this machine is, the fact remains that a 3D printer can produce more complex designs. For example, a herringbone pattern can help with alignment issues. It has been done many times. You can even use a resin printer, although you might prefer to stick with FDM.

Continue reading “Simple CNC Gear Production With Arduino” →

DIy Arduino FM radio enclosure with the lid off, showing the electronics inside

DIY Arduino Due TEA5767 FM Radio

October 8, 2022 by Dave Walker 10 Comments

Older hackers will remember that a crystal set radio receiver was often one of the first projects attempted. Times have changed, but there’s still something magical about gathering invisible signals from the air and listening to the radio on a homemade receiver. [mircemk] has brought the idea right up to date by building an FM radio with an OLED display, controlled with a rotary encoder.

The design is fairly straightforward, based as it is on another project that [mircemk] found on another site, but the build looks very slick and would take pride of place on any hacker’s workbench. An Arduino Due forms the heart of the project, controlling a TEA5767 module, an SH1106 128×64 pixel OLED display and a rotary encoder. The sound signal is passed through an LM4811 headphone amplifier for private listening, and a PAM8403 Class D audio amplifier for the built-in loudspeaker. The enclosure is made from PVC panels, and accented with colored adhesive tape for style.

It’s easier than ever before to quickly put together projects like this by connecting pre-built modules and downloading code from the Internet, but that doesn’t mean it’s not a worthwhile way to improve your skills and make some useful devices like this one. There are so many resources available to us these days and standing on the shoulders of giants has always been a great way to see farther.

We’ve shown some other radio projects using Arduinos and the TEA5767 IC in the past, such as this one on a tidy custom PCB, and this one built into an old radio case.

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close-up image of a philodendron houseplant with electrodes attached, connected to a robot arm holding a machete

(Mostly) Harmless Houseplant Wields Machete

October 6, 2022 by Dave Walker 27 Comments

In a straight fight between a houseplant and a human, you might expect the plant to be at a significant disadvantage. So [David Bowen] has decided to even the odds a little by arming this philodendron with a robot arm and a machete.

The build is a little short on details but, from the video, it appears that adhesive electrodes have been attached to the leaves of the recently-empowered plant and connected directly to analog inputs of an Arduino Uno. From there, the text tells us that the signals are mapped to movements of the industrial robot arm that holds the blade.

It’s not clear if the choice of plant is significant, but an unarmed philodendron appears to be otherwise largely innocuous, unless you happen to be a hungry rodent. We hope that there is also a means of disconnecting the power remotely, else this art installation could defend itself indefinitely! (or until it gets thirsty, at least.) We at Hackaday welcome our new leafy overlords.

We have covered the capabilities of plants before, and they can represent a rich seam of research for the home hacker. They can tell you when they’re thirsty, but can they bend light to their will? We even held a Plant Communication Hack Chat in 2021.

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Arduino IDE v2.0 screen with callout tags to identify features

Arduino IDE 2.0 Is Here

September 28, 2022 by Dave Walker 84 Comments

Arduino have released the latest version of their Integrated Development Environment (IDE), Version 2.0 and it is a big step up from the previous release, boasting plenty of new features to help you to develop your code more easily.

As the de-facto way for beginners to get into programming hardware, more experienced users have sometimes complained about what they see as the over-simplistic IDE — even lacking relatively basic features such as autocomplete. The new version provides this, and much more besides. Continue reading “Arduino IDE 2.0 Is Here” →

Adding A Third Wheel (And Speed Boost) To An Electric Scooter

September 24, 2022 by Donald Papp 7 Comments

The story of how [Tony]’s three-wheeled electric scooter came to be has a beginning that may sound familiar. One day, he was browsing overseas resellers and came across a new part, followed immediately by a visit from the Good Ideas Fairy. That’s what led him to upgrade his DIY electric scooter to three wheels last year, giving it a nice speed boost in the process!

The part [Tony] ran across was a dual brushless drive unit for motorizing a mountain board. Mountain boards are a type of off-road skateboard, and this unit provided two powered wheels in a single handy package. [Tony] ended up removing the rear wheel from his electric scooter and replacing it with the powered mountain board assembly.

He also made his own Arduino-based interface to the controller that provides separate throttle and braking inputs, because the traditional twist-throttle of a scooter wasn’t really keeping up with what the new (and more powerful) scooter could do. After wiring everything up with a battery, the three-wheeled electric scooter was born. It’s even got headlights!

[Tony]’s no stranger to making his own electric scooters, and the fact that parts are easily available puts this kind of vehicular experimentation into nearly anybody’s hands. So if you’re finding yourself inspired, why not order some stuff, bolt that stuff together, and go for a ride where the only limitation is personal courage?

Minimal Tic Tac Toe Business Card

September 24, 2022 by Stephen Ogier 38 Comments

The PCB business card has long been a way for the aspiring electronics engineer to set themself apart from their peers. Handing out a card that is also a two player game is a great way to secure a couple minutes of a recruiter’s time, so [Ryan Chan] designed a business card that, in addition to his contact information, also has a complete Tic-Tac-Toe game built in.

[Ryan] decided that an OLED display was too expensive for something to hand out and an LED matrix too thick, so he decided to keep it simple and use an array of 18 LEDs—9 in each of two colors laid out in a familiar 3×3 grid. An ATmega328p running the Arduino bootloader serves as the brains of the operation. To achieve a truly minimal design [Ryan] uses a single SMD pushbutton for control: a short press moves your selection, a longer press finalizes your move, and a several-second press switches the game to a single-player mode, complete with AI.

If you’d like to design a Tic-Tac-Toe business card for yourself, [Ryan] was kind enough to upload the schematics and code for his card. If you’re still pondering what kind of PCB business card best represents you, it’s worth checking out cards with an updatable ePaper display or a tiny Tetris game.

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Sketch of a Tandy TRS-80 Model 100 with Arduino Mega 2560

TRS-80 Model 100 Gets Arduino Heart Transplant

September 23, 2022 by Dave Walker 4 Comments

When [Stephen Cass] found himself with a broken Tandy TRS-80 Model 100 portable computer, the simplest solution was to buy another broken one and make one working computer from two non-working computers. However, this left him with a dilemma — what to do with the (now even more) broken one left over?

LCD layout is unusual by modern standard, but optimized for fast updates

Naturally, he did what a lot of us would do and used modern hardware to interface with the original parts that still work. In this case it meant replacing the motherboard with an Arduino Mega 2560.

Luckily, the Model 100 has a substantial fanbase and there’s a lot of helpful information available online, including the detailed service manual, that helped [Stephen] to understand how to drive the unusual display. The LCD has a resolution of 240×64 pixels, which are broken down into eight zones of 50×32 pixels, and two zones of 40×42 pixels. Each zone is then further divided into four banks, eight pixels tall, so that each column of eight pixels corresponds to a single byte.

Every one of the ten zones is controlled by an individual HD44102 driver IC, connected to a 30-bit wide bus for selecting the correct chip, bank and column.

With the Arduino handling the data, the old LCD still needed a -5 V supply for contrast and an RC filter to smooth out the PWM signal [Stephen] is using to adjust the viewing angle.

With the new interface, [Stephen] is able to access all of the pixels on the original display, and to use modern graphics libraries such as displayio. With the display issue solved, he intends to use a separate Teensy 4.1 to connect with the keyboard matrix and provide a VT100 terminal interface.

Upcycling old, broken hardware can be a lot of fun and is always educational. Understanding why certain design decisions were made at a time when the engineering trade-offs were different can lead to insights that are directly relevant to modern designs when resources get tight. In this case, the quirky LCD drivers were a response to making the display of text as efficient as possible, so as not to overburden the processor.

The TRS-80 computers are ripe for hacking, with their “built-for-service” designs, and we’ve featured a few in the past. Some have replaced the motherboard with something newer, like [Stephen], whereas others have also replaced the display, or connected them to the cellphone network.

Have you found new ways to get old hardware working? Tell us in the comments below or send us a message on the Hackaday tips line.

Thanks to [nb0x0308] for the tip!