Slick Web Oscilloscope Is Ready In A Flash (Literally)

February 22, 2021 by Tom Nardi 27 Comments

A bench oscilloscope is one of the most invaluable tools in the hardware hacker’s arsenal, but even the slimmest digital models are a bit large to be part of your everyday electronic carry. Sure you could throw one of those cheap pocket scopes in your bag, but what if there was an even easier way to take a peek at a few signals while you’re on the go?

For those who roam, the Arduino-web-oscilloscope project created by [David Buezas] is worth a close look. Using the Web Serial API built into recent versions of Google’s Chrome browser, this project allows you to pop open a software oscilloscope without installing anything locally. Whether it’s a public computer or that cheap Chromebook you keep around for emergencies, a valuable tool is just a few clicks away.

Flashing the MCU from the web interface.

Of course, there has to be some hardware involved. Despite what you might think given the name of the project, the code currently only supports the Logic Green LGT8F328P microcontroller. This cheap ATmega328P clone not only runs at 32 Mhz but according to [David], many operations can be done in fewer clock cycles than on the original 328P. In short it’s fast, and fast is good if you want more samples.

One of the best parts about this project is that a function to flash the firmware to the LGT8F328P is built right in the web interface. With the oscilloscope running in the browser, you just need to plug in a blank board, click the button to flash it, and start taking measurements. You could outfit a whole classroom or hackerspace with basic oscilloscopes in minutes, with a per-seat cost of just a few bucks.

Now as you might expect, there are some pretty hard limits on what you can realistically measure with this setup. For one thing, the board can’t handle anything higher than 5 volts. Even the cheapest oscilloscope kit is still going to be an upgrade, but the fact you can spin this up almost anywhere for the cost of a cheap MCU board makes it hard to complain about the results.

[Thanks to Bill for the tip.]

A DIY Electronic Load With A Twist

June 6, 2020 by Tom Nardi 13 Comments

If you’re testing a power supply or battery pack, an electronic load is a nice tool to have. By watching the voltage as you crank up the resistance, you can verify the unit’s real-world capabilities quickly and easily. But [Xavier Bourlot] wanted a bit more information than is generally afforded by these devices, so he came up with his own scratch built load that can measure the voltage at multiple points in the circuit.

Now at first glance, it might not be obvious why you’d want such a capability. But [Xavier] is looking to do something very specific with this device: analyze the efficiency of DC-DC converters. The idea is that if the electronic load can measure the voltage on both sides of the converter, it can calculate what kind of losses are being incurred.

Could you do this with a multimeter and a traditional electronic load? Sure. But if it’s the kind of thing you’ll be doing a lot of, it’s not hard to see why this method would be preferable.

But even if you ignore the converter analysis capabilities, this looks to be a very useful device to have around the lab. [Xavier] says it can sink more than 5 amps, and handle an input voltage as high as 100 volts. Powered by an ATmega328P, the load is also fully programmable and even features an I2C expansion port that you can use to hang additional hardware or sensors on. The stock firmware is already quite capable, and the list of future enhancements has some very interesting entries such as the ability to log data over serial or to a SD card.

We’ve seen a number of programmable electronic load projects over the years, ranging from Arduino shields to VFD equipped units that would be the pride of any hacker’s bench.

A VFD Wall Thermometer

December 28, 2019 by Tom Nardi 5 Comments

Want to build something using VFD tubes, but don’t need yet another clock project? In that case, this wall mounted temperature and humidity display created by [commanderkull] might be exactly what you’re looking for. With six IV-11 tubes, this display is a practical way to add some of that gorgeous blue-green glow to your home or office.

The USB powered display uses a XL6009 and an XL7015 to provide the 24 V and 1.8 V needed by the IV-11 tubes, respectively. Both of which can be disconnected with jumpers to shut down the tubes without powering off the entire device, a useful feature when programming and debugging the display’s ATmega328P microcontroller. Each tube is connected to the ATmega with an 74HC595 shift register and a UDN2981 driver. Temperature and humidity data is provided, perhaps unsurprisingly, by the exceptionally common DHT22 sensor.

If you are looking to build another clock with these style tubes, there’s certainly enough prior art out there to get you started. We’ve also seen faux VFDs that you could use for either project, just in case you aren’t looking to deal with the voltage requirements and relative rarity of the real thing.

A Colorful Way To Play Chess On An ATmega328

August 24, 2019 by Maya Posch 2 Comments

We’ve all seen those chess computers that consist out of a physical playing field, and a built-in computer that would indicate where you should put its pieces while inputting the position of your pieces in some way. These systems are usually found in a dusty cardboard box in a back room’s closet, as playing like this is fairly cumbersome, and a lot depends on the built-in chess computer.

This take by [andrei.erdei] on this decades-old concept involves an ATmega328p-based Arduino Pro Mini board, a nice wooden frame, and 4 WS2812-based 65×65 mm RGB 8×8 LED matrices, as well as some TTP223 touch sensors that allow one to control the on-board cursor. This is the sole form of input: using the UP and RIGHT buttons to select the piece to move, confirm with OK, then move to the new position. The chess program will then calculate its next position and indicate it on the LED matrix.

Using physical chess pieces isn’t required either: each 4×4 grid uses a special pattern that indicates the piece that occupies it. This makes it highly portable, but perhaps not as fun as using physical pieces. It also kills the sheer joy of building up that collection of enemy pieces when you’ve hit that winning streak. You can look at the embedded gameplay video after the break and judge for yourself.

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Xpedit Is A Mood Ring For Mother Nature

August 7, 2019 by Kristina Panos 4 Comments

Whether you’re in the woods or way up a mountain, basic knowledge of your environment can yield a lot of power. The more you know about the temperature, humidity, barometric pressure, and your altitude, the easier it is to predict future weather and stick to your height limits. Sure, you could buy some pre-fab doohickey that does all of this, but why? [DIYMechanics] shows how easy it is to build your own pocket-sized weather station for under $20.

Xpedit’s brain is an ATMega328 running on a 20MHz crystal heartbeat. The atmospheric readings come from a BME280, a nifty all-in-one module that’s available for pennies on Ali. The rotary encoder handles user inputs, and the simple interface displays on an OLED. There’s even a tiny compass embedded in the 3D printed case.

We really like the custom alarm feature, which can buzz you via vibe motor if you’ve climbed too high, or the pressure is dropping. [DIYMechanics] has Xpedit completely open-sourced, so trek on down to the GitHub for the latest Eagles, Gerbers, and INOs. Don’t have a USBtiny ISP yet? He’s got the plans for that, too.

Maybe you’re the indoorsy type who’d rather read about mountainous jungle adventures than experience them firsthand. Add some weather-driven ambiance to your book nook by hacking an IKEA cloud lamp.

Booting The Game Boy Advance Into Bluetooth

June 21, 2019 by Tom Nardi 8 Comments

While it might not be quite as revered as its predecessor, the Game Boy Advance is arguably the peak of “classic” handheld gaming, before things got all 3D and dual screen on us. One of its best features is the so-called multiboot mode, which allows the GBA to download a program from its link port. Officially this feature was introduced so you could play multiplayer with your friends even if they didn’t have the game cartridge, but naturally it didn’t take long for hackers to realize you can use it to run arbitrary code on an unmodified system.

[Shyri Villar] has put this capability to excellent use with a plug-in board that allows a stock GBA to be used as a general purpose Bluetooth HID controller. Now you can emulate GBA games on your computer while using the real thing as your input device. Or if that’s a bit too redundant for you, then any 2D game you think could benefit from the classic Game Boy control layout.

An ATmega328P on the board initiates the multiboot sequence when the system powers up, and feeds it the GBA program that’s stored on a W25Q32 chip. Once the code is running on the GBA, it communicates with a common HC-05 Bluetooth module through the same link port. To perform this handoff, [Shyri] uses a HCF4066 switch IC to literally change the pin assignments in the connector from the SPI used to upload the ROM to the UART lines of the Bluetooth module.

With everything powered from the 3.3 V provided by the GBA’s link port, and some software niceties like the ability to store Bluetooth pairing information for subsequent device connections, this is actually a very practical gadget. The fact that you can do this on a completely stock GBA is very compelling, especially considering some of the previous Bluetooth Game Boy modifications we’ve seen. Granted the market might be somewhat limited, but with a custom PCB and a 3D printed enclosure, we could see this potentially being a popular accessory for the classic handheld. It’s not like it can be any more niche than using the GBA as a remote display for your multimeter.

Simple Arduino Universal Remote Control

June 4, 2019 by Tom Nardi 11 Comments

The infrared remote control might not hold the seat of honor in the average home theater setup that it once enjoyed, but it’s not quite out to pasture yet. After all, what are you going to use to stop Netflix once the Chromecast invariably disconnects from your phone? As long as there are devices out there that will respond to commands blasted their way via an IR LED, hackers will be looking to get in on the action.

In an effort to make IR remote hacking just a bit easier, [sjm4306] has submitted his Remoteduino for the 2019 Hackaday Prize. With this handy tool in your arsenal, you can focus on developing the software side of your next IR remote project without worry about the hardware. Just upload your code, and get clicking.

As you might imagine, the design is rather simple. On the front edge of the PCB you’ve got the prerequisite IR LED, and a healthy supply of tactile buttons that your code can use as input. The remote features a fairly standard layout on the top half, complete with silkscreened labels for the common functions, but below that [sjm4306] has packed in six general purpose buttons that can be used for whatever you like.

The Remoteduino is powered by an ATmega328P, and the whole thing runs on a CR2032 cell mounted on the backside. [sjm4306] mentions in his write-up on Hackaday.io that battery life was always a consideration during development of the Remoteduino, so he’s made a few energy-saving considerations. Using the internal 8 MHz oscillator instead of an external crystal shaved a bit off the top, and the aggressive sleep routines got him the rest of the way. In testing, he estimates the battery should last a few years even with daily use.

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