Improbably Cheap Pocket Welder Gets An ESP32 Makeover

November 4, 2019 by Dan Maloney 25 Comments

If you move in certain shady circles, you may have noticed the crop of improbably cheap “pocket welders” popping up on the market these days. They’re all variations on a theme, most with wildly optimistic specs minimal accessories of the lowest possible quality. But their tiny size and matching price make them irresistible to the would-be welder, as well as attractive to hardware hackers.

With a 220-V outlet in the garage waiting to be filled and well-knowing the risks, [Mr. RC-Cam] purchased one of these diminutive welding machines. Its shortcomings were immediately apparent, and a complete rework of the welder was undertaken. After addressing safety issues like the lack of a ground connection, [Mr. RC-Cam] added a color-matched 3D-printed hood to house a fancy new LCD touchscreen display. Backing that up is an ESP32 with Bluetooth, which supports remote control via a key fob. He also added a current sense board that uses the welder’s current shunt to measure welding current. Expediently calibrated using a waffle iron and a milli-ohmmeter, the sensor showed that the 200A max advertised for the welder was more like 100A. He tried adding some big electrolytics to fix the current issues, but no dice. With a decent stinger and ground clamp, the modified welder is good enough for his needs, and much was learned in the process. We call that a hacking win.

As an aside, [This Old Tony] recently did a review on a similar welder if you want more details on the internals. We also covered the conversion of a buzz-box to a TIG welder recently, should that be more your style.

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Bluetooth Control With Chrome

October 17, 2019 by Al Williams 4 Comments

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.

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PVC Pipe Turned Portable Bluetooth Speaker

October 7, 2019 by Tom Nardi 7 Comments

We’ve always felt that sections of PVC pipe from the home improvement store are a criminally underutilized construction material, and it looks like [Troy Proffitt] feels the same way. Rather than trying to entirely 3D print the enclosure for his recently completed portable Bluetooth speaker, he combined printed parts with a piece of four inch pipe from the Home Depot.

While using PVC pipe naturally means your final hardware will have a distinctly cylindrical look, it does provide compelling advantages over trying to print the entire thing. For one, printing an enclosure this large would have taken hours or potentially even days. But by limiting the printed parts to accessories like the face plate, handle, and caps, [Troy] reduced that time considerably. Of course, even if you’re not in a rush, it’s worth mentioning that a PVC pipe will be far stronger than anything your desktop FDM printer is likely to squirt out.

[Troy] provides links for all the hardware he used, such as the speakers, tweeters, and the Bluetooth audio board itself. The system is powered by an 1800 mAh 3S RC-style battery pack that he says lasts for hours, though he also links to a wall adapter that can be used if you don’t mind being tethered. Unfortunately it doesn’t look like he has any internal shots of the build, but given the relatively short parts list, we imagine it’s all fairly straightforward inside.

While this is certainly a respectable looking build considering it started life in the plumbing aisle, we have to admit that we’ve seen some portable Bluetooth speakers with fully 3D printed enclosures in the past that looked absolutely phenomenal. The tradeoff seems pretty clear: reuse existing materials to save time, print them if you don’t mind reinventing the wheel occasionally.

Ask Hackaday: Does Your Car Need An Internet Killswitch?

October 1, 2019 by Lewin Day 103 Comments

Back in the good old days of carburetors and distributors, the game was all about busting door locks and hotwiring the ignition to boost a car. Technology rose up to combat this, you may remember the immobilizer systems that added a chip to the ignition key without which the vehicle could not be started. But alongside antitheft security advances, modern vehicles gained an array of electronic controls covering everything from the entertainment system to steering and brakes. Combine this with Bluetooth, WiFi, and cellular connectivity — it’s unlikely you can purchase a vehicle today without at least one of these built in — and the attack surface has grown far beyond the physical bounds of bumpers and crumple zones surrounding the driver.

Cyberattackers can now compromise vehicles from the comfort of their own homes. This can range from the mundane, like reading location data from the navigation system to more nefarious exploits capable of putting motorists at risk. It raises the question — what can be done to protect these vehicles from unscrupulous types? How can we give the user ultimate control over who has access to the data network that snakes throughout their vehicle? One possible solution I’m looking at today is the addition of internet killswitches.

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Tiny ESP32 Fits Inside USB-A Connector

September 28, 2019 by Bryan Cockfield 24 Comments

The ESP32 was introduced a few years ago as an inexpensive way to outfit various microcontrollers with WiFi or Bluetooth. Since then it has been experimented with and developed on, thanks to its similarities to the ESP8266 and the ability to easily program it. Watching the development of this small chip has truly been fascinating as it continues to grow. Or, in this case, shrink.

The latest development in the ESP32 world comes from [femtoduino] who, as the name suggests, makes very small things. This one is a complete ESP32 which fits inside a USB-A connector. The brains of the projects is the ESP32-D2WD which is a dual core chip with 2 Mb of memory, making it more than capable. In fact, a big part of this project was [femtoduino]’s modifications to MicroPython in order to allow it to run on this chipset. For that alone, it’s cool.

This project is impressive for both reasons, both the size and the addition to the MicroPython libraries. If you need something really really tiny, for whatever reason, you might want to look into picking up one of these. Be careful though, and be sure to get the latest version of the SDK.

Smartphone Case Doubles As Chording Keyboard, With Gesture Inputs

September 25, 2019 by Donald Papp 6 Comments

Smartphones and other modern computing devices are wonderful things, but for those with disabilities interacting with them isn’t always easy. In trying to improve accessibility, [Dougie Mann] created TypeCase, a combination gestural input device and chording keyboard that exists in a kind of symbiotic relationship with a user’s smartphone.

With TypeCase, a user can control a computer (or the smartphone itself) with gestures, emulate a mouse, or use the device as a one-handed chording keyboard for text input. The latter provides an alternative to voice input, which can be awkward in public areas.

The buttons and motion sensors allow for one-handed button and gestural input while holding the phone, and the Bluetooth connectivity means that the device acts and works just like a wireless mouse or keyboard. The electronics consist mainly of an Adafruit Feather 32u4 Bluefruit LE, and [Dougie] used 3D Hub’s on-demand printing service to create the enclosures once the design work was complete. Since TypeCase doubles as a protective smartphone case, users have no need to carry or manage a separate device.

TypeCase’s use cases are probably best expressed by [Dougie]’s demo video, embedded below. Chording keyboards have a higher learning curve, but they can be very compact. One-handed text input does remind us somewhat of a very different approach that had the user make gestures in patterns reminiscent of Palm’s old Graffiti system; perhaps easier to learn but not nearly as discreet.

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Over-Engineered Cat Door Makes Purrfect Sense

September 16, 2019 by Kristina Panos 21 Comments

On paper, pet doors are pretty great. You don’t have to keep letting the cat in and out, and there should be fewer scratches on the door overall. Unfortunately, your average pet door is indiscriminate, and will let any old creature waltz right in. Well, [Jeremiah] was tired of uninvited critters, so he built a motorized door with a built-in bouncer. Now, only animals with pre-approved BLE tags can get in.

The bouncer is a Raspi 3 running Node-RED, which scans continuously for BLE advertisements from the cats’ collars. [Jeremiah] settled on Tile tags because they’re reliable and cat-proof. The first version used an Arduino and RFID tags for the cats, but they had to get too close to the door to trigger it.

We love [Jeremiah]’s choice of door actuator, a 12V retractable car antenna. [Jeremiah] uses the antenna itself to lift and lower the removable lockout panel that comes with the door. He removed the circuit that retracts the antenna when power is lost, so that power outages don’t become free-for-alls for shelter-seeking animals.

There’s also a nice feature for slow creatures—the door won’t close until 15 seconds after the last BLE ad, so they cats won’t ever have to Indiana Jones it through the opening. Magnetic switches currently limit the door travel at the top and bottom, though [Jeremiah] will eventually replace them with standard switches. Paw at the break until you get a walk-through video.

Cats will be cats, and the ones that go outside will probably rack up a body count. Here’s a cat door that looks for victims clenched between cat jaws and starts a 15-minute lockout period.

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