Using PoE With A Raspberry Pi 3 For About Two Bucks

-

When the Raspberry Pi 3 Model B+ was announced in March of 2018, one of its new features was the ability to be (more easily) powered via Power-over-Ethernet (PoE), with an official PoE HAT for the low price of just twenty-one USA bucks. The thing also almost worked as intended the first time around. But to some people this just isn’t good enough, resulting in [Albert David] putting out a solution he calls “poor man’s PoE” together for about two bucks.

His solution makes it extra cheap by using so-called passive PoE, which injects a voltage onto the conductors of the network cable being used for PoE, without bothering with any kind of handshake. In general this is considered to be a very reliable (albeit non-standard) form of PoE that works great until something goes up in smoke. It’s also ridiculously cheap, with a PoE injector adapter (RJ-45 plug & 2.1×5.5 mm power jack to RJ-45 jack) going for about 80 cents, and a DC-DC buck converter that can handle the input of 12V for about 50 cents.

The rest of the $2 budget is mostly spent on wiring and heatshrink, resulting in a very compact PoE solution that plugs straight into the PoE header on the Raspberry Pi 3 board, with the buck converter outputs going into the ground and +5V pins on the Raspberry Pi’s GPIO header.

A fancier solution would implement any of the standard PoE protocols to do the work of negotiating a suitable voltage. Maybe this could be the high-tech, $5 solution featuring an MCU and a small PCB?



from CommaFeed - Real Time Trends Network https://ift.tt/2mcxoIW
via IFTTT

Comments

Post a Comment

Popular posts from this blog

Takeaways from the outcry over Dior’s Johnny Depp perfume ad: Tuesday Wake-Up Call

-
Welcome to Ad Age’s Wake-Up Call, our daily roundup of advertising, marketing, media and digital news. You can sign up to get an audio version of this briefing on your Alexa device. Dior pulls a perfume ad starring Johnny Depp Yet another luxury brand just had to backtrack after a culturally insensitive move. Dior on Friday pulled an ad for its “Sauvage” perfume, as Business of Fashion reports ; the spot starred Johnny Depp playing guitar in the desert while a Native American dancer, Canku One Star, performed in traditional dress. The company portrayed the spot as “an authentic journey deep into the Native American soul.” But the brand was quickly accused of cultural appropriation. Critics seemed most troubled by the juxtaposition of Native American imagery with the word "Sauvage"—which means “wild” in French, but which also evokes the history of labeling indigenous groups as “savages.”  LVMH-owned Parfums Christian Dior had apparently tried to proceed cautiously. It coo
Read more

When the coronavirus infodemic strikes

-
Image
Social media sites are stepping up their efforts in the war against misinformation… specifically, the coronavirus/COVID-19 infodemic . There’s a seemingly endless stream of potentially dangerous misinformation flying around online related to the COVID-19 pandemic, and that could have fatal results. It’s boomtown in fake-news land riding high on the wave of people being left with their tech devices 24/7. I myself regularly see everything posted online from “hand gel is an immunizer” (nope) and “children can’t be affected” (not true) to “UK rules mean domestic abuse survivors have to stay with their abusive spouse” (absolutely not true at all and hugely dangerous to claim).  We even have engineers being spat on thanks to 5G conspiracy theories potentially resulting in transmission of coronavirus . Turns out a global pandemic is a lightning rod for pushing people to conspiracy theories galore, to the extent that some folks have to go hunting for guides to wean their family members a
Read more

Patch, Or Your Solid State Drives Roll Over And Die

-
Image
Expiration dates for computer drives? That’s what a line of HP solid-state drives are facing as the variable for their uptime counter is running out. When it does, the drive “expires” and, well, no more data storage for you! There are a series of stages in the evolution of a software developer as they master their art, and one of those stages comes in understanding that while they may have a handle on the abstracted world presented by their development environment they perhaps haven’t considered the moments in which the real computer that lives behind it intrudes. Think of the first time you saw an SQL injection attack on a website, for example, or the moment you realised that a variable type is linked to the physical constraints of the number of memory locations it has reserved for it. So people who write software surround themselves with an armoury of things they watch out for as they code, and thus endeavour to produce software less likely to break. Firmly in that arena is the size
Read more