#FreePCB via Twitter to 2 random RTs

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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/2M6Xp4n

Pi-powered Atari 5200 multi-ROM cartridge (MultiCart)

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Dr. Scott M. Baker has a nice write-up about building a multi-ROM cartridge for his Atari 5200 using Raspberry Pi:

The Atari 5200 is a vintage gaming system from the early 1980s. At the time I owned a 2600, but I always wanted a 5200. Well, in 2018 I finally decided to find one on eBay and buy it. I learned that the first thing you want to do after attaining a new gaming console is to get your hands on every available game cartridge for it, so I made this multi-ROM cartridge.
A multi-ROM cartridge, or “MultiCart” is a cartridge that contains more than one ROM image. There are multiple ways to go about this from selector switches to pick the cartridge you want, to built-in in game menu systems. I decided to go the route of using a Raspberry Pi for the user interface, making a WEB UI available to pick which cartridge is used.
The goal is not simply to play retro games on modern hardware — there’s any number of emulation solutions for that. The goal is to play retro games on retro hardware, but use a modern system to load the game image into the console.

See the full post at smbaker.com and the GitHub repository here.

Check out the video after the break.

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Free PCB Sunday: Pick your PCB

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We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will get a coupon code for the free PCB drawer tomorrow morning. Pick your own PCB. You get unlimited free PCBs now – finish one and we’ll send you another! Don’t forget there’s free PCBs three times every week:

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Be sure to use a real e-mail in the address field so we can contact you with the coupon.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.
  • PCBs are scrap and have no value, due to limited supply it is not possible to replace a board lost in the post

Be the first to comment, subscribe to the RSS feed.

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App note: High-side smart-FETs with analog current sense

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Smart-FETs application from ON Semiconductors. Link here (PDF)

This application note describes the structure and design philosophy of ON Semiconductor High Side Smart−FETs, and serves as a guide to understand the operation of the device in specific applications. The scope of this document is limited to Smart−FETs with analog current sense output.

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Free PCB coupon via Facebook to 2 random commenters

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Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week:

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • We’ll contact you via Facebook 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/2NPx9M4

Particle sensor with LoRa

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Mare published a new build:

Particle sensors could be cheap and easy to use. Disadvantage of lowest cost PM sensors is lack of “calibration”. The best method to measure particle content dispensed in the air is to collect the air sample and analyse it off-line in the laboratory with proper equipment (not cheap at all). Optical particle counting sensors use the light scattering method to detect and count particles in the operating concentration range in a given environment. A laser light source illuminates a particle as it is pulled through the detection chamber. As particles pass through the laser beam, the light source becomes obscured and is recorded on the photo or light detector. The light is then analyzed and converted to an electrical signal providing particulate size and quantity to predict concentrations in real time.

See the full post on Mare & Gal Electronics blog.

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Energy Meter module to analyze the electrical grid parameters and consumption

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Boris Landoni from Open Electronics writes about a new open source energy meter project:

In the first installment, you had the opportunity of learning about our energy meter, and of learning about its details, with special attention the technical ones. Our energy meter is based on the coupling – by means of two measuring transformers – to an integrated circuit, that enables the detection of the values as for voltage and current, in addition to the corresponding phase angles, so to be able to know the real, the reactive and the apparent power, in addition to the phase angle (cosφ). We developed a software to be paired to our measuring board, so that it may be used for the configuration and calibration of the integrated circuit, and for the real-time display of the electrical measurings that it has carried out.

More details at Open-Electronics.org.  Be sure to see Part 1 here.

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Multichannel logic probe and pulsar

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Dilshan Jayakody published a new build:

This is 8 channel CMOS logic probe and pulsar which is useful when designing, testing and faultfinding in digital circuits. This circuit is designed using commonly available CMOS logic ICs which including couple of 4069 hex inverters and 4040 binary counter.
Logic probe of this system is based on 4069 hex inverters and it indicate logic high and low states with 2 LEDs. Logic pulsar of this circuit is capable to generate 12 frequencies and highest frequency it can generate is 420kHz. This pulsar generate square wave with 50% duty cycle and it’s average raise time is 16µS.

See the full post on Dilshan Jayakody’s blog.

from Dangerous Prototypes https://ift.tt/2Ljk8xv

#FreePCB via Twitter to 2 random RTs

IRToy-600x369

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/2v2Pei6