Not-Quite-So-Hot Stuff: A Thermal Exam On The Latest Raspberry Pi

December 6, 2019 by Jenny List 53 Comments

When the Raspberry Pi 4 was first launched, one of its few perceived flaws was that it had a propensity to get extremely hot. It’s evidently something the Pi people take very seriously, so in the months since they have addressed the problem with a set of firmware updates. Now they’ve taken a look at the effect of the fixes in a piece on the Raspberry Pi web site, and it makes for an interesting comparison.

The headline figure is that all updates together remove about a watt of power from the load, a significant quantity for what is still a board that can run from a capable phone charger. Breaking down the separate parts of the updates is where the meat of this story lies though, as we see the individual effects of the various USB, memory, power management and clocking updates. In temperature terms they measure an on-load drop from 72.1 °C to 58.1 °C, which should be a significant improvement for any Pi 4 owner.

There is a debate to be had over in what role a computer such as a Pi should serve. As successive revisions become ever more desktop-like in their capabilities, do they run the risk of abandoning the simplicity of a cheap Linux box as a component that makes us come back for more? It’s a possibility, but one they have very well addressed by developing the Pi Zero. They have also successfully avoided the fate of the Arduino — inexorably tied to its ATmega powered original line despite newer releases. As we have frequently said when reviewing Raspberry Pi competitors, it’s the software support that sets them apart from the herd, something this power-draw story demonstrates admirably.

Gameslab: The Other FPGA Game Console Badge

December 6, 2019 by Dan Maloney 2 Comments

Anyone who was at Supercon will no doubt remember the badges that dangled around everyone’s neck. Some were reasonable, while some were neck-straining monsters that added anything and everything to hack the badge into something cool. We saw everything from AI cameras to a fully autonomous vehicle being worn with pride.

Sadly, one that we missed was Gameslab, [Craig J. Bishop]’s FPGA-based portable game console. No, not that FPGA-based game console; in an example of great minds thinking alike, [Craig] had actually been toying with his own handheld console design for quite some time. And we have to say the results are stunning.

The FPGA at the heart of this is a Xilinx Zynq FPGA-ARM Cortex A9 combo SoC, normally a prohibitively expensive monster of a chip. When [Craig] found “refurbished” Zynq chips on eBay for less than 10% of the cost of new units, it was literally game-on for the build. The console required a six-layer PCB to support the big BGA chip and the hundreds of support components around it. There’s a 5″ TFT touchscreen with a video controller implemented in the FPGA, a stereo sound system, and all the buttons and thumbsticks you’d expect on a modern console.

For our money, the best part is the case, about which [Craig] has yet to share any details. But it looks like a machined aluminum plate with wide chamfers around each cutout that contrast nicely with the brushed surface. We’ll be looking forward to more details on that and on progress with Gameslab.

A Magnetron Tear Down

December 5, 2019 by Al Williams 27 Comments

Microwave ovens are everywhere, and at the heart of them is a magnetron — a device that creates microwaves. [DiodeGoneWild] tore one apart to show us what was inside and how it works. If you decide to do this yourself, be careful. The magnetron may have insulators made of beryllium oxide and inhaling dust from the insulator even one time can cause an incurable lung condition.

Luckily, you can’t get a lung problem from watching a video. In addition to just seeing the guts of the magnetron, there are also explanations about how everything works with some quick sketches to illustrate the points.

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The Heat Of The Moments – Location Visualization In Python

December 5, 2019 by Sven Gregori 7 Comments

Have you ever taken a look at all the information that Google has collected about you over all these years? That is, of course, assuming you have a Google account, but that’s quite a given if you own an Android device and have privacy concerns overruled by convenience. And considering that GPS is a pretty standard smartphone feature nowadays, you shouldn’t be surprised that your entire location history is very likely part of the collected data as well. So unless you opted out from an everchanging settings labyrinth in the past, it’s too late now, that data exists — period. Well, we might as well use it for our own benefit then and visualize what we’ve got there.

Location data naturally screams for maps as visualization method, and [luka1199] thought what would be better than an interactive Geo Heatmap written in Python, showing all the hotspots of your life. Built around the Folium library, the script reads the JSON dump of your location history that you can request from Google’s Takeout service, and overlays the resulting heatmap on the OpenStreetMap world map, ready for you to explore in your browser. Being Python, that’s pretty much all there is, which makes [Luka]’s script also a good starting point to play around with Folium and map visualization yourself.

While simply just looking at the map and remembering the places your life has taken you to can be fun on its own, you might also realize some time optimization potential in alternative route plannings, or use it to turn your last road trip route into an art piece. Just, whatever you do, be careful that you don’t accidentally leak the location of some secret military facilities.

[via r/dataisbeautiful]

How Safe Is That Ultrasonic Bath For Flux Removal?

December 5, 2019 by Dan Maloney 30 Comments

How do you clean the residual flux off your boards? There are plenty of ways to go about the job, ranging from “why bother?” to the careful application of isopropyl alcohol to every joint with a cotton swab. It seems like more and more people are turning to ultrasonic cleaners to get the job done, though, and for good reason: just dunk your board and walk away while cavitation does the work for you.

But just how safe is it to sonically blast the flux off your boards? [SDG Electronics] wanted to know, so he ran some cleaning tests to get to the bottom of things. On the face of it, dunking a PCB in an aqueous cleaning solution seems ill-advised; after all, water and electricity famously don’t mix. But assuming all the nooks and crannies of a board can be dried out before power is applied, the cleaning solution itself should be of little concern. The main beef with ultrasonic cleaning seems to be with the acoustic energy coupling with mechanical systems on boards, such as crystal oscillators or micro-electrical-mechanical systems (MEMS) components, such as accelerometers or microphones. Such components could resonate with the ultrasonic waves and be blasted to bits internally.

To test this, [SDG Electronics] built a board with various potentially vulnerable components, including the popular 32.768-kHz crystal, cut for a frequency quite close to the cleaner’s fundamental. The video below goes into some detail on the before-and-after tests, but the short story is that nothing untoward happened to any of the test circuits. Granted, no components with openings as you might find on some MEMS microphones were tested, so be careful. After all, we know that ultrasound can deal damage, and if it can levitate tiny styrofoam balls, it might just do your circuit in.

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Automated Cat Feeder Leaves Little To Chance

December 5, 2019 by Tom Nardi 11 Comments

We often like to say that if something is worth doing, then it’s worth overdoing. This automatic cat feeder built by [krizzli] is a perfect example of the principle. It packs in far more sensors and functions than its simple and sleek outward appearance might suggest, to the point that we think this build might just set the standard for future projects.

The defining feature of the project is a load cell located under the bowl, which allows the device to accurately measure out how much feed is being dispensed by weight. This allows the feeder to do things such as detect jams or send an alert once it runs out of food, as well as easily adjust how much is dispensed according to the animal’s dietary needs. To prevent any curious paws from getting into the machine while it’s doling out the food, the lid will automatically open and close during the filling process, complete with optical sensors to confirm that it moved as expected.

All of the major components of the feeder were printed out on a Prusa i3 MK3S, and [krizzli] says that the feed hopper can be scaled vertically if necessary. Though at the current size, it’s already packing around a week’s worth of food. Of course, this does depend on the particular feline you’re dealing with.

In terms of electronics, the feeder’s primary control comes from an ESP8266 (specifically, the Wemos D1 Mini), though [krizzli] also has a Arduino Pro Mini onboard so there’s a few more GPIO pins to play with. The food is dispensed with a NEMA 17, and a 28-BYJ48 stepper is in charge of moving the lid. A small OLED on the side of the feeder gives some basic information like the time until the next feeding and the dispensed weight, but there’s also a simple API that lets you talk to the device over the network. Being online also means the feeder can pull the time from NTP, so kitty’s mealtime will always be on the dot.

Over the years we’ve seen an incredible array of automatic cat feeders, some of which featuring the sort of in-depth metrics possible when you’ve got on onboard scale. But we can’t help but be impressed with how normal this build looks. If nothing else, of all the feeders we’ve seen, this one is probably the most likely to get cloned and sold commercially. They say it’s the most sincere form of flattery.

Don’t Forget The Baby!

December 5, 2019 by Jenny List 47 Comments

It must be a common worry among parents, that they might forget their offspring and leave them in the car where they would succumb to excessive heat. So much so that [Matt Meerian] has produced an alarm that issues a verbal reminder to check for the youngster when the vehicle is turned off.

It’s a simple enough device, with an ATmega328, an off-the-shelf MP3 module, and a power supply regulator to deliver 5 V into a pair of supercapacitors from the vehicle accessory socket’s 12 V. The idea is that the power is cut when the vehicle ignition is turned off, and that the supercaps have enough energy within them to play the reminder sample for the driver to check for forgotten children.

We can’t help remarking that a percentage of cars leave their accessory sockets turned on all the time, so it would be interesting to ponder how one might detect the car being turned off in that case. He muses about using a surplus cell phone instead of his ATmega328, perhaps the MEMS sensor on a phone could also be used to detect the vibrations of the engine stopping as it was turned off. Such cars notwithstanding, this unit is a straightforward solution to the problem in hand.