#FreePCB via Twitter to 2 random RTs

Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

from Dangerous Prototypes https://ift.tt/2xvRUd9

This clock really, really doesn’t want to tell you the time

What’s worse than a clock that doesn’t work? One that makes an “unbearably loud screeching noise” every minute of every day is a strong contender.

That was the aural nightmare facing YouTuber Burke McCabe. But rather than just fix the problem, he decided, in true Raspberry Pi community fashion, to go one step further. Because why not?

The inventor of the clock holds it with the back facing the camera to show us how it works and is looking down at it.

Burke showing YouTube viewers his invention

On the back of the clock, alongside the built-in mechanism controlling the clock’s arms, Burke added a Raspberry Pi to control a motor, which he hooked up to a webcam. The webcam was programmed using open computer vision library OpenCV to detect whenever a human face comes into view. Why would a clock need to know when someone looks at it? We’ll come to that.

First up, more on how that webcam works. OpenCV detects when a pair of eyes is in view of the webcam for three consecutive frames. You have to be really looking at it, not just passing it – that is, you have to be trying to tell the time. When this happens, the Raspberry Pi rotates the attached motor 180 degrees and back again.

But why? Well:

A clock that falls off the wall when you look at it

hello #invention #robot #raspberrypi

Burke has created a clock which, when you look at it to tell the time, falls off the wall.

We know: you want your own. So do we. Thankfully, Burke responded to calls in the comments on his original video for a more detailed technical walkthrough, and, boy, did he deliver.

How I made A clock that falls off the wall when you look at it

I dunno why I sounded depressed in this video Original Video – https://www.youtube.com/watch?v=R3HUuf6LGQE&t=41s The Code – https://ift.tt/3a7XGyX;

In his walkthrough video, you get a good look at Burke’s entire setup, including extra batteries to make sure your Raspberry Pi gets enough juice, advice on how to get to grips with the code, and even the slots your different coloured wires need to go in. And so very, very much duct tape. Who’s going to start a GoFundMe to get Burke the glue gun sticks he so desperately needs? And hit subscribe for his YouTube channel while you’re at it!

The post This clock really, really doesn’t want to tell you the time appeared first on Raspberry Pi.

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