Microbatteries On The Grid

March 27, 2020 by Bryan Cockfield 35 Comments

Not everybody has $6500 to toss into a Tesla Powerwall (and that’s a low estimate), but if you want the benefits of battery storage for your house, [Matt]’s modular “microbattery” storage system might be right up your alley. With a build-as-you-go model, virtually any battery can be placed on the grid in order to start storing power from a small solar installation or other power source.

The system works how any other battery installation would work. When demand is high, a series of microinverters turn on and deliver power to the grid. When demand is low, the batteries get charged. The major difference between this setup and a consumer-grade system is that this system is highly modular and each module is networked together to improve the efficiency of the overall system. Its all tied together with a Raspberry Pi that manages the entire setup.

While all of the software is available to set this up, it should go without saying that working with mains power is dangerous, besides the fact that you’ll need inverters capable of matching phase angle with the grid, a meter that handles reverse power flow, a power company that is willing to take the power, and a number of building code statutes to appease. If you don’t have all that together, you might want to go off-grid instead.

Launch Console Delivers Enjoyment To Software Deployment

March 26, 2020 by Kristina Panos 3 Comments

Sometimes it feels as though all the good physical interactions with machines have disappeared. Given our current germ warfare situation, that is probably a good thing. But if fewer than ten people ever will be touching something, it’s probably okay to have a little fun and make your own interfaces for things.

Fun definitely seems to be some of the inspiration behind [sethvoltz]’s retro-style launch console. This two-factor authorization token-based system is responsible for an important task that usually receives no fanfare — deploying code to production.

The console is centered around a Yubikey, which is type of hardware dongle for 2FA. Flipping the guarded toggle switch will initiate the launch sequence, and then it’s time to insert the Yubikey into the 3D-printed lock cylinder and wait for authorization. If the Raspberry Pi decides all systems are go, then the key can be turned ninety degrees and the mushroom button mashed. You have our permission to peek at the declassified demo after the break. Stick around for a CAD view inside the lock cylinder.

Console culture was great, but the old full-size cabinets sure took up a lot of space. If you’re more of a hardware person, check out this mini-console for testing multiple servos.

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This Is Not An Argument Bot

March 17, 2020 by Kristina Panos 41 Comments

While in-person arguments are getting harder to come by these days, we’ll always have the internet (hopefully). So what can you do to stay on your game in a time when a little levity is lauded? Build an argument bot and battle wits with the best — a stern-faced John Cleese!

This latest offering from [8 Bits And A Byte] refers to a Monty Python sketch featuring an argument service — an office with a receptionist who will take your money and send you down the hall for a healthy and heated discussion. If you’ve never gone on a Monty Python binge, well, it’s probably as good a time as any.

Electronics-wise, the argument bot is a pretty simple build. A Raspberry Pi B+ outfitted with a Google AIY hat listens to your side of things and decides which bones to pick. Your obviously misguided statements are then matched with DialogFlow intents, and dissent is sent back through the speaker. Meanwhile, Mr. Cleese’s jaw moves up and down on a printed and servo-driven linear actuator while he maintains a stiff upper lip. Before you go off on that Python binge, check out the build video after the break.

Have you seen what can happen two robots argue? ‘Tis but a scratch. Continue reading “This Is Not An Argument Bot” →

CherryPi Mechanical Keyboard Warrants A Long Look

March 4, 2020 by Kristina Panos 33 Comments

[Gosse Adema] has been poking a Microsoft Natural Elite for the last 20 years, and the curvy old girl is about to give out. Looks like he got bit pretty hard by the DIY mechanical keyboard bug in his quest to replace her. Luckily for us, he documented his build.

Where do we start? A first keeb is decently-sized undertaking, but [Gosse] turned it up a notch and made it as low-profile as he could — it’s 2cm thick with the keycaps on. This ultimately meant designing the board such that the anti-ghosting diodes sit inside a cutout underneath their respective switches, which are low-profile Cherry MX Reds. There is no Eagle template for those yet, so [Gosse] whipped one up and milled a prototype PCB before deciding to go the fab route.

The Raspberry Pi Zero W that controls this keeb lives in a separate controller box in the name of slimness. If you are as-yet unimpressed by this build for some reason, [Gosse] even rolled his own firmware, which he explains as part of this epic journey. Seems the only thing he didn’t do was mold his own keycaps, but not everyone wants to type on blanks. We wonder if [Gosse] is aware of the terrifically low-slung Kailh choc switches, although prefab keycap options for those are even more limited.

Speaking of, here’s a tasty choc-filled game pad.

A Simple Yet Feature-Packed Programmable DC Load

February 28, 2020 by Dan Maloney 14 Comments

If you’ve got the hankering to own a lab full of high-end gear but your budget is groaning in protest, rolling your own test equipment can be a great option. Not everything the complete shop needs is appropriate for a DIY version, of course, but a programmable DC load like this one is certainly within reach of most hackers.

This build comes to us courtesy of [Scott M. Baker], who does his usual top-notch job of documenting everything. There’s a longish video below that covers everything from design to testing, while the link above is a more succinct version of events. Either way, you’ll get treated to a good description of the design basics, which is essentially an op-amp controlling the gate of a MOSFET in proportion to the voltage across a current sense resistor. The final circuit adds bells and whistles, primarily in the form of triple MOSFETS and a small DAC to control the set-point. The DAC is driven by a Raspberry Pi, which also supports either an LCD or VFD display, an ADC for reading the voltage across the sense resistor, and a web interface for controlling the load remotely. [Scott]’s testing revealed a few problems, like a small discrepancy in the actual amperage reading caused by the offset voltage of the op-amp. The MOSFETs also got a bit toasty under a full load of 100 W; a larger heatsink allows him to push the load to 200 W without releasing the smoke.

We always enjoy [Dr. Baker]’s projects, particularly for the insight they provide on design decisions. Whether you want to upgrade the controller for a 40-year-old game console or giving a voice to an RC2014, you should check out his stuff.

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Raspberry Pi 4 Offers Up 2 GB For The Price Of One

February 27, 2020 by Tom Nardi 54 Comments

The Raspberry Pi 4 represents a significant performance increase over previous generations, unlocking potential applications that were simply beyond the abilities of these diminutive Single Board Computers (SBCs) in the past. Some would even argue that the Pi 4, with a quad-core Cortex-A72 running at 1.5 GHz, now holds its own as a lightweight ARM desktop computer for those interested in finally breaking free from x86.

In light of the considerable upgrade in processing power, the choice to outfit the base model Pi 4 with just 1 GB of RAM always seemed a bit odd. So it’s little surprise that the Raspberry Pi Foundation has decided to shift things around and lower the price of the 2 GB model to the traditional $35. In a blog post this morning, Eben Upton said that with RAM prices falling over the last year, the company thought it was time they passed the savings onto the customer.

This change comes just two days before the Pi’s 8th birthday. There has been speculation that the Pi 4 is capable of operating with 8 GB of RAM and unveiling that news to coincide with this anniversary would have been a clever marketing move. Alas, it looks like we’ll have to continue to wait.

For those who are invested in the 1 GB model, have no fear. Rather than delete the product from the lineup entirely, the company will be keeping it available for anyone who needs it. So if you’ve got a commercial or industrial application that might not take kindly to the hardware getting switched out, you’ll still have a source of spares. That said, the pricing for the 1 GB model won’t be changing, so there’s no cost advantage to using it in new designs.

Combined with news that compatibility issues the Pi 4 had with generic USB-C power supplies was fixed with an under the radar board revision, it seems there’s never been a better time to upgrade to the latest and greatest version of everyone’s favorite Linux board. Happy Birthday, Raspberry Pi.

Now You Can Be Big Brother Too, With A Raspberry Pi License Plate Reader

February 26, 2020 by Jenny List 60 Comments

If you are wowed by some of the abilities of a Tesla but can’t quite afford one, perhaps you can enhance your current ride with a few upgrades. This was what [Robert Lucian Chiriac] did with his Land Rover, to gain some insight into automotive machine vision he fitted it with a Raspberry Pi and camera with an automatic number plate recognition system.

This bracket should find a use in a few projects.

His exceptionally comprehensive write-up takes us through the entire process, from creating a rather useful set of 3D-printed brackets for a Pi and camera through deciding the combination of artificial intelligence software components required, to making the eventual decision to offload part of the processing to a cloud service through a 4G mobile phone link. In this he used Cortex, a system designed for easy deployment of machine learning models, which he is very impressed with.

The result is a camera in his car that identifies and reads the plates on the vehicles around it. Which in a way has something of the Big Brother about it, but in another way points to a future in which ever more accessible AI applications self-contained without a cloud service become possible that aren’t quite so sinister. It’s an inevitable progression whose privacy questions may go beyond a Hackaday piece, but it’s also a fascinating area of our remit that should be available at our level.

You can see the system in action in the video below the break, as well as find the code in his GitHub repository.

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