Hackaday Links: March 7, 2021

March 7, 2021 by Dan Maloney 13 Comments

It’s March, which means Keysight is back in the business of giving away a ton of test gear. Keysight University Live starts on March 15, with daily events the first week followed by a string of weekly live events through April. We always enjoy these Keysight events; sure, they’re clearly intended to sell more gear, but the demos and tutorials are great, and we always learn a lot. There’s also a feeling of community that feels similar to the Hackaday community; just a bunch of electronics nerds getting together to learn and share. If you’re interested in that community, or even if you’re just looking for a chance to win something from the $300,000 pile of goodies, you’ll need to register.

There’s another event coming up that you’ll want to know about: the 2021 Open Hardware Summit. Because 2021 is the new 2020, the summit is being held virtually again, this year on April 9. Tickets are on sale now, and we’re told there are still plenty of Ada Lovelace Fellowships available to those who consider themselves to be a minority in tech. The Fellowship covers the full cost of a ticket; it usually covers travels costs too, but sadly we’re still not there yet.

Once we do start traveling again, you might need to plan more carefully if cities start following the lead of Petaluma, California and start banning the construction of gas stations. The city, about 40 miles (64 km) north of San Francisco, is believed to be the first city in the United States to ban new gas station construction. The city council’s decision also prevents gas station owners from expanding, reconstructing, or relocating existing gas stations. The idea is to create incentives to move toward non-fossil fuel stations, like electric vehicle charging stations and hydrogen fueling. Time will tell how well that works out.

Go home Roomba — you’re drunk. That could be what Roomba owners are saying after an update semi-bricked certain models of the robotic vacuum cleaners. Owners noted a variety of behaviors, like wandering around in circles, bumping into furniture, and inability to make its way back to base for charging. There’s even a timelapse on reddit of a Roomba flailing about pathetically in a suspiciously large and empty room. The drunken analogy only goes so far, though, since we haven’t seen any reports of a Roomba barfing up the contents of its dust bin. But we’re still holding out hope.

And finally, if you’re not exactly astronaut material but still covet a trip to space, you might luck out courtesy of Japanese billionaire Yusaku Maezawa. He’s offering to pay the way for eight people from around the world on a planned flight to the Moon and back in 2023. Apparently, Maezawa bought up all the seats for the flight back in 2018 with the intention of flying a group of artists to space. His thinking has changed, though, and now he’s opening up the chance to ~~serve as ballast~~ join the crew to pretty much any rando on the planet. Giving away rides on Starship might be a harder sell after this week’s test, but we’re sure he’ll find plenty of takers. And to be honest, we wish the effort well — the age of routine civilian space travel can’t come soon enough for us.

Logic Meter Aims To Make Hobby Electronics Troubleshooting Easier

January 28, 2021 by Dan Maloney 28 Comments

The basic test instrument suite — a bench power supply, a good multimeter and perhaps an oscilloscope — is extremely flexible, but not exactly “plug and play” when it comes to diagnosing problems with some common hardware setups. A problem with a servo driver, for example, might be easy enough to sort of with a scope, but setting everything up to see what’s going on with the PWM signal takes some time.

There’s got to be a better way to diagnose hobby electronics woes, and if [Bob Alexander] has his way, his “Logic Meter”, or something very close to it, will be the next must-have bench tool. The Logic Meter combines some of the functionality of an oscilloscope and a logic analyzer into a handy instrument that’s as easy to use as a multimeter. The Logic Meter’s probes connect to logic-level signals in a circuit and can be set up to capture or send serial data, either directly to or from a UART or via an SPI bus connection. There are also functions for testing servos and similar devices with a configurable PWM output. [Bob] rounds out the functionality with a GPS simulator and a simple logic analyzer, plus some utility functions.

The beauty part of the Logic Meter is that [Bob] has left where it goes next largely up to the community. He’s got a GitHub repo with details on the PIC32-based hardware, and the video below makes it clear that this is just a jumping-off point to further work that he hopes results in a commercial version of the Logic Meter. That’s a refreshing attitude, and we hope it pays off; from the look of a few of [Bob]’s retrocomputing makeovers, something like the Logic Meter could come in pretty handy.

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Blue Pill As A Nerdy Swiss Army Knife

November 22, 2020 by Inderpreet Singh 15 Comments

Not everyone can afford an oscilloscope, and some of us can’t find a USB logic analyzer half the time. But we can usually get our hands on a microcontroller kit, which can be turned into a makeshift instrument if given the appropriate code. A perfect example is buck50 developed by [Mark Rubin], an open source firmware to turn a STM32 “Blue Pill” into a multi-purpose test and measurement instrument.

buck50 comes with a plethora of functionality built in which includes an oscilloscope, logic analyzer, and bus monitor. The device is a two way street and also comes with GPIO control as well as PWM output. There’s really a remarkable amount of functionality crammed into the project. [Mark] provides a Python application that exposes a text based UI for configuring and using the device though commands and lots of commands which makes this really nerdy. There are a number of options to visualize the data captured which includes gnuplot, gtk wave and PulseView to name a few.

[Mark] does a fantastic job not only with the firmware but also with the documentation, and we really think this makes the project stand out. Commands are well documented and everything is available on [GitHub] for your hacking pleasure. And if you are about to order a Blue Pill online, you might want to check out the nitty-gritty of the clones that are floating around.

Thanks [JohnU] for the tip!

Custom Electronic Load Makes Use Of Gaming PC Tech

October 18, 2020 by Tom Nardi 14 Comments

At first glance, you might think the piece of hardware pictured here is a modern gaming computer. It’s got water cooling, RGB LED lighting, and an ATX power supply, all of which happen to be mounted inside a flashy computer case complete with a clear window. In truth, it’s hard to see it as anything but a gaming PC.

In actuality, it’s an incredible custom electronic load that [EE for Everyone] has been developing over the last four months that’s been specifically designed to take advantage of all the cheap hardware out there intended for high-performance computers. After all, why scratch build a water cooling system or enclosure when there’s such a wide array of ready-made ones available online?

The “motherboard” with single load module installed.

Inside that fancy case is a large PCB taking the place of the original motherboard, to which four electronic load modules slot into. Each of these loads is designed to accept a standard Intel CPU cooler, be it the traditional heatsink and fan, or a water block for liquid cooling. With the current system installed [EE for Everyone] can push the individual modules up to 275 watts before the temperatures rise to unacceptable levels, though he’s hoping to push that a little higher with some future tweaks.

So what’s the end game here? Are we all expected to have a massive RGB-lit electronic load hidden under the bench? Not exactly. All of this has been part of an effort to design a highly accurate electronic load for the hobbyist which [EE for Everyone] refers to as the “Community Edition” of the project. Those smaller loads will be derived from the individual modules being used in this larger testing rig.

We’ve actually seen DIY liquid cooled electronic loads in the past, though this one certainly sets the bar quite a bit higher. For those with more meager requirements, you might consider flashing a cheap imported electronic load with an open source firmware to wring out some extra functionality.

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Textmeter Tells Its Tale

September 24, 2020 by Brian McEvoy 5 Comments

One time-proven method to make a lesson memorable is to make it a story, but that is not easy if your core material is the repair log of a rotted out analog ammeter. Most folks don’t need a 300A meter on their drill press, so [Build Comics] converted it to a text display and describes the procedure like they are writing a comic book. He is using HDLO-3416 LED cluster arrays for that dated-but-legible industrial feel, and everything looks right at home in a box made from oak and steel. Even the USB cord even gets a facelift by running it inside a fabric shoelace. In our own lives, covering charging cables is a hack on its own because we don’t want to fumble with the wrong charger when it is time to sleep or drive. Glow-in-the-dark cord upgrades, anyone?

We don’t have a pre-operation picture of the subject, but the innards suggest that it comes from the bottom of an industrial scrap pile. There is a cross-hatch pattern on the front plate, which hinted at 3D printing, but if you look closely at the early images, you can see that it is original. There is a nodeMCU board to fetch the date information and control the four alphanumeric displays. Except for the red lights, all the new hardware hides behind wood or steel, so this old workhorse’s aesthetic lives on and has a story to share that is a delight to read.

If you enjoy reading [Build Comics] and their adventurous recollections, we forecast you’ll enjoy this weather display, or maybe it is time to check out their clock, but we want to plant the seed of literary build logs.

Amp Volt Ohm Meter Model 8 Mark III From The 1960s

February 16, 2020 by Al Williams 22 Comments

There’s hardly any piece of test equipment more fundamental than a volt ohm meter. Today you’re likely to have a digital one, but for most of history, these devices had real needle meters. The AVOmeter Model 8 Mark III that [Jeff Tranter] shows off had an odd banana-shaped meter. Maybe that goes with the banana plugs. You can get a closer view of this vintage piece of equipment in the video after the break.

Even the outside description of the meter is interesting. There were several unique features. For example, if the meter goes full scale a little button pops out and disconnects the probes to protect the meter. Another unusual control reversed the polarity of the leads so you didn’t have to swap them manually.

Some of the other features will be familiar to anyone who has used a good analog meter. For example, the meter movement has a mirror under the needle. This is used to make sure you are looking straight down on the needle when making readings. If you can see the reflection of the needle, then you are off to one side and will not read the precise value you are interested in.

If you only want to see the insides, [Jeff] teases you until around the six minute mark. There are no active devices and this meter is old enough to not use a printed circuit board. The AC ranges work with a transformer and germanium diodes. The rest of the circuit is mostly a bunch of resistors.

The point to point wiring always makes us wonder who built this thing sixty years ago. You can only wonder what they would think if they knew we were looking at their handiwork in the year 2020.

We see a lot of meter clocks, but it would be a shame to tear this unique meter apart for its movement. Perhaps someone should make a clock that outputs a voltage to a terminal so you could read it with your favorite meter. This instrument was probably pretty precise for its day, but we doubt it can match a modern 6.5 digit digital instrument.

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How To Design A Low Cost Probe-Oscilloscope

December 16, 2019 by Gerrit Coetzee 22 Comments

[Mark Omo] sends in his write up on the design of what should hopefully be a sub-$100 oscilloscope in a probe.

Many problems in engineering can be solved simply by throwing money at the them. It’s really when you start to apply constraints that the real innovation happens. The Probe-Scope Team’s vision is of a USB oscilloscope with 60MHz bandwidth and 25Msps. The cool twist is that by adding another probe to a free USB port on your computer you’re essentially adding a channel. By the time you get to four you’re at the same price as a normal oscilloscope but with an arguably more flexible set-up.

The project is also open source. When compared to popular oscilloscopes such as a Rigol it has pretty comparable performance considering how many components each channel on a discount scope usually share due to clever switching circuitry.

The probe is based around an Analog Devices ADC whose data is handled by a tag team of a Lattice FPGA and a 32bit PIC micro controller. You can see all the code and design files on their github. Their write-up contains a very thorough explanation of the circuitry. We hope they keep the project momentum going!