‘Daytime Running Light’ module (DRL) with ATtiny85

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Nicu Florica writes:

A reader of my sites and blogs, Mr. Liviu Hinoveanu wanted to replace classical DRL module made with 555 with Attiny85 programmed in Arduino style.
He send me the schematic and PCB designed with Livewire and PCB Wisard software
After I undertand what module must work, I write DRL_ATtiny85.ino sketch.
Mr. Hinoveanu made module and upload sketch in ATiny85 like in article from Programarea unui microcontroler ATTiny85 cu sketch Arduino.

See the full post on his blog, Arduinotehniq.

Check out the video after the break.

 

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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.

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DEC PDP 11 / 24 CPU CARD: State of the art design from 1979

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DEC PDP 11/24 CPU card teardown from Electronupdate:

This is a cpu card from a class of computers known as mini-computers.
By the late 1970’s DEC was about to be eclipsed by the microcomputer. At the same time this card was in production the 68000 and 8086 16-bit class micro processors were also in the market: their superior cost would soon take much of DEC’s low end market.
The card uses their FONZ-11 LSI chip set. Most interestingly the CPU instructions are micro-coded and placed into separate chips: the instruction set could be expanded at will by adding more “303E”s. Typically this would be for a floating-point instruction set.

More details at Electronupdate blog.

Check out the video after the break.

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Automatic fan controller for server racks

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Dilshan Jayakody published a new build:

In this post we describe fan controller which we designed for our 9U wall mount server cabinet. This fan controller is designed to drive a 12V DC cooler fan with pre-configured intervals or by monitoring the temperature of the server cabinet.
Core components of this fan controller is CD4060 binary counter, LM35 temperature sensor and LM358 operational amplifier. In this design CD4060 is used as long duration timer and it can configured to trigger cooler fan from 1-minute and up to 4-hour.

See the full post on his blog here.

from Dangerous Prototypes http://bit.ly/2pPKpa1

Negative impedance converters

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An article discusses the negative resistance and negative impedance converter from Analog Zoo:

“Negative resistance” may seem like a purely academic concept, but can be easily realized in practice with a handful of common components. By adding a single resistor to a standard non-inverting op amp circuit, we can create a negative impedance converter, which has applications in load cancellation, oscillator circuits, and more.

More details at Analogzoo.com.

Check out the video after the break.

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Why electrolytic capacitors are actually kinda shitty

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Afroman writes, “Electrolytic capacitors are common, but knowledge of their limitations is uncommon. A demonstration is shown highlighting the difference in performance between electrolytic and ceramic capacitors in power supplies. Other topics discussed in the video: Electrolytic capacitor construction, ceramic capacitors, ESR, ESL, impedance curves, why “0.1uF”, and more.”

Via Afrotechmods.

Check out the video after the break.

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Alexa (Echo) with ESP32 and ESP8266 – Voice controlled relay

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Rui Santos writes, “In this project, you’re going to learn how to control the ESP8266 or the ESP32 with voice commands using Alexa (Amazon Echo Dot). As an example, we’ll control two 12V lamps connected to a relay module. We’ll also add two 433 MHz RF wall panel switches to physically control the lamps.”

More info at randomnerdtutorials.com.

Check out the video after the break.

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Reading a VGA monitor’s configuration data with I2C and a PocketBeagle

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Ken Shirriff wrote an article showing how to read the monitor’s config data using the I2C protocol and a board with an I2C port:

Have you ever wondered how your computer knows all the characteristics of your monitor— the supported resolutions, the model, and even the serial number? Most monitors use a system called DDC to communicate this information to the computer.1 This information is transmitted using the I2C communication protocol—a protocol also popular for connecting hobbyist devices. In this post, I look inside a VGA monitor cable, use a tiny PocketBeagle (a single-board computer in the BeagleBone family) to read the I2C data from an LCD monitor, and then analyze this data.

More details at Ken Shirriff’s blog.

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#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/2pIzu1E