3D Printed Dump Truck Carries Teeny Loads

October 27, 2023 by Lewin Day 8 Comments

What do you do when you already have a neat little radio-controlled skid-steer loader? Well, if you’re [ProfessorBoots], you build a neat little dump truck to match!

The dump truck is built out of 3D printed components, and has proportions akin to a heavy-duty mining hauler. The dump bed and wheels were oversized relative to the rest of the body to give it a more cartoonish look.

An ESP32 is the brains of the operation. The build is powered by a nifty little 3.6 V rechargeable lithium-ion battery with an integral Micro USB charge port. It’s paired with a boost converter to provide a higher voltage for the servos and motors. Drive is to the rear wheels, thanks to a small DC gear motor. Unlike previous skid-steer designs from [ProfessorBoots], this truck has proper servo-controlled steering. The printed tires are wrapped in rubber o-rings, which is a neat way to make wheels that grip without a lot of fuss. The truck also has a fully-functional dump bed, which looks great fun to play with.

The final build pairs great with the loader that [ProfessorBoots] built previously.

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Simple Badge Is Simple, But It’s Yours

October 26, 2023 by Al Williams 8 Comments

Making conference badges, official or unofficial, has become an art form. It can get pretty serious. #badgelife.

But DEFCON-goers aren’t the only people making fancy personalized nametags. Hams often had callsign badges going back as far as I can remember. Most were made of engraved plastic, but, at some point, it became common to put something like a flashing LED on the top of the engraved antenna tower or maybe something blinking Morse code.

Going back to that simpler time, I wanted to see if I could make my own badge out of easily accessible modules. How easy can it be? Let’s find out. Along the way, we’ll talk about multicore programming, critical sections, namespaces, and jamming images into C++ code. I’ll also show you how to hijack the C preprocessor to create a little scripting language to make the badge easier to configure.

Bottom Line Up Front

The photo shows the Pico badge. It has an RP2040 CPU but not a proper Raspberry Pi Pico. The Waveshare RP2040-Plus clone has a battery connector and charger. It also has a reset button, and this one has 16 MB of flash, but you don’t need that much. The LCD is also a Waveshare product. (This just happened to work out. I bought all of this stuff, and I don’t even know anyone at Waveshare.) The only other thing you need is a USB C cable and a battery with an MX 1.25 connector on it with the correct polarity. Hardware done! Time for software.

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A Paper Printer For QR Code Menus

October 26, 2023 by Lewin Day 25 Comments

Do you miss the days of thumbing through a sticky, laminated booklet to order your food? Sick of restaurants and their frustrating electronic menus? Fear not, for [Guy Dupont] and his QR code menu printer are here to save the day.

Yes, that’s right — it’s a lunchbox-sized printer designed to spit out a paper version of a digital menu. Using a Tiny Code Reader from Useful Sensors, the device can scan a QR code at a restaurant to access its menu. A Seeed Studio XIAO ESP32 takes the link, and then passes it to a remote computer which accesses the menu online and screenshots it. The image is processed with TesseractOCR to extract food items and prices, and the data is then collated into a simple text-only format using ChatGPT. The simplified menu is finally sent to a thermal printer to be spat out on receipt paper for your casual perusal.

[Guy] was inspired to build the project after hating the experience of using QR code menus in restaurants and bars around town. It’s his latest project that solves an everyday problem, it makes a great sequel to his smart jeans that tell you when your fly is down.

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A Nicer Controller For Cheap Power Supply Modules

October 25, 2023 by Lewin Day 3 Comments

These days, you can get all kinds of cheap power supply modules off a variety of online vendors. A lot of examples from brands like Juntek and Drok often have pretty poor interfaces though, with a couple of tactile buttons and a simple 7-segment display. [rin67630] decided to whip up a better controller with a much more informative display.

The controller is designed to work with programmable buck converter modules like the DPS3806, Buck3603, and BST900. It’s based on a TTGO ESP32 with an integrated color TFT LCD. It displays voltage at the input and output, the same for current, along with current setpoints. It also allows for control of a fan and charge cycles if so desired, and it has the ability to fetch time from an NTP server for proper scheduling. There’s also a web interface complete with graphs for really diving down into the nitty-gritty. Future plans include adding an MPPT solar charging capability.

If you’ve ever wanted a cheap power supply module with really low-level control and rich data display, this could be just what you need. Meanwhile, you’ve got your own neat power supply in the works, don’t hesitate to drop us a line.

Level Your Trailer Or RV With This Nifty Helper Device

October 25, 2023 by Lewin Day 30 Comments

Getting your RV or trailer parked nice and level is key to getting a good night’s sleep. Traditional methods involve bubble levels and trial and error, but [MJCulross] wanted something better. Enter the Teensy RV Leveling Helper.

The device uses an accelerometer to detect the pitch and roll angles of the RV. It then displays these on a small screen, and performs calculations on how much the RV must be raised at each corner to bring it level. The RV’s width and wheelbase can be entered via a simple touchscreen interface to ensure the calculations are correct. There’s also a trailer mode which calculates three-point leveling figures for the wheels and the hitch, as opposed to the four-wheeled RV mode.

The result is that the correct leveling blocks can be selected first time when parking up the RV or trailer. It’s a lot less tedious than the usual method of parking, leveling, checking, and then leveling again.

We don’t see a lot of camper hacks around here, but we’ve noticed a new trend towards lightweight cycle campers in recent years. If you’ve found your own nifty hacks for your home on the open road, don’t hesitate to let us know!

Compact, Gesture-Based Remote Control Over Bluetooth

October 14, 2023 by Donald Papp 5 Comments

[AlexMiller11] shared a project for a DIY gesture-sensing remote control that acts like a Bluetooth keyboard, capable of controlling media and presentations on a computer with a high degree of accuracy.

The device recognizes eight different gestures and controls a host PC over Bluetooth.

The hardware is a Silicon Labs xG24 dev kit, a small IoT-focused board able to be powered by a CR2032 cell. Part of what makes it all work is the six-axis IMU sensor, but the rest is the software to interpret that data and figure out what motions the user is trying to do. That happens with a Neuton.AI model and SDK, a tiny but effective machine learning framework for small devices.

How does it actually work? The device acts as a Bluetooth HID, and gets connected to a PC in the same was as a regular Bluetooth keyboard. Once that’s done, recognized gestures are printed out the serial port as well as sent via Bluetooth to the host machine. Media can then be played, paused, volume adjusted, presentations controlled, and more. More details are on the project’s GitHub repository. There’s also a demo video that explains exactly what’s going on, embedded below the page break.

Machine learning is a way of using software to solve the kinds of problems humans are not very good at writing programs to solve, and accurate gesture recognition is a good example. Not all such applications require heaps of overheating GPUs, either. We’ve seen the concept of a neural network stripped down to its bare essentials running on an Arduino Uno, for those who would like to better appreciate the fundamentals.

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This 3D Printable Soldering Air Filter Really Sucks

October 14, 2023 by Kristina Panos 24 Comments

If you solder (and we know you do), you absolutely need ventilation, even for that lead-free stuff. Fortunately, [tinyboatproductions] has gotten into air quality lately and is here to help you with their snappy 3D printed air-filtering design.

At the heart of this build is a 120 mm notoriously-quiet Noctua fan coupled with a carbon filter. It does what you’d think — position the fan the right way and it sucks the air through the filter, which catches all those nasty particles.

The only problem is that the Noctua uses PWM, so there’s no governing it with a just potentiometer. To get around this, [tinyboatproductions] introduced an Arduino Nano and a buck converter, both of which were admittedly a bit overkill. Now the speed can be controlled with a pot.

Once control of the fan was sorted, [tinyboatproductions] decide to add an OLED display to show the fan speed and power condition, which is a nice touch. Be sure to check out the build video after the break.

If this doesn’t have quite enough features for you, here’s one that’s battery powered.

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