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PIC16F1459 USB stack light controller

Posted on Wednesday, April 17th, 2019 in PIC by DP | No Comments

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Glen Akins published a new build:

After using the PIC16F1459 to build numerous USB HID input devices including a giant keyboard, a tiny keyboard, and a big red button, it was time to see if the PIC16F1459 could be used to control outputs too. Sticking with the industrial theme, I chose to build a USB controller for a, um, stack of industrial stack lights.

See the full post on Photons, Electrons, and Dirt blog.

Crystal oscillator teardown

Posted on Wednesday, April 17th, 2019 in Teardowns by DP | No Comments

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Here’s a tear down of a crystal oscillator and a look at the silicon controller from Electronupdate:

 Inside is a ceramic circuit board.  Ceramic has a low coefficient of thermal expansion which is probably very desirable here. It will also not absorb moisture.  All of this would affect the frequency.

More details on Electronupdate blog.

Check out the video after the break. (more…)

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, April 16th, 2019 in Free PCBs by DP | No Comments

BP

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.

WiFiChron alarm clock

Posted on Tuesday, April 16th, 2019 in clock, wireless by DP | No Comments

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Here’s a cool WiFiChron clock with 8-character alphanumeric LED display by Florinc:

For WiFiChron, two cascaded modules make an 8-character display functionally similar to HDSP-2534, but bigger and more visible. With the “Display Abstraction Layer” already in place, software support should be easy to integrate, since controlling it with the HT16K33 breakout allows the re-use of the above mentioned Adafruit LED backpack library. For maximum compatibility, I followed the same wiring, then connected the two extra segments, A2 and D2, to pin 10 (not connected for the 14-segment backpack) and pin 11 (connected to the DP), respectively.

More details on Wise time with Arduino blog.

App note: The behavior of electro-magnetic radiation of power inductors in power management

Posted on Sunday, April 14th, 2019 in app notes by DP | No Comments

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Würth Elektronik app note on EM radiation emission from power inductors. Link here (PDF)

DC-DC converters are widely used in power management applications and the inductor is one of the key components. The usual focus is on electrical performance characteristics such as RDC, RAC and core losses. But, the electro-magnetic radiation characteristics can often be overlooked.

Due to the switching action in SMPS, AC voltage/current is produced over the inductor. Since, an inductor can, in effect, operate as a transmitting loop antenna, the electromagnetic radiation depends on a number of factors. These include the source properties such as core material, shielding material and the orientation of the start of the winding amongst others.

Electromagnetic radiation of an inductor in the low frequency spectrum range (100 kHz to 30 MHz), which is caused by the switching frequency and harmonics, is dependent on whether the inductor is shielded and the winding properties. Whereas, in the high frequency spectrum range (30 MHz to 1 GHz), where emissions are caused by ringing frequencies and their harmonics, the electromagnetic radiation is more dependent on the shielding characteristics of the core material, switching frequency and transitions of the switching converter.

App note: How to use power inductors

Posted on Sunday, April 14th, 2019 in app notes by DP | No Comments

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A great guide from TDK about power inductors used in DC-DC converters. Link here

As electronic devices become more advanced, the power supply voltage of LSIs used in them is lowered, so their power consumption can be reduced and their speed increased. However, a decrease in the power supply voltage also causes the requirements regarding voltage fluctuations to become more severe, creating a need for high-performance DC-DC converters to fulfill these characteristic requirements, and power inductors are important components that greatly affect their performance.

DIY 3D printer project

Posted on Wednesday, April 10th, 2019 in 3D fabrication by DP | No Comments

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Frank documented a 3D printer build, called Hephaestus:

I finally did it, I designed and built my own 3D printer. This is in no way “the best 3D printer”. Instead, this was an epic and nightmare project that exercised my ability to engineer and build my own CNC machine. Along the way, I figured out what I did well and what I did badly, mistakes were made and sometimes fixed, even ignored.

You can find the build log on Eleccelerator project page.

RetroZero (retropie handheld)

Posted on Monday, April 8th, 2019 in R-Pi by DP | No Comments

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Facelesstech published a new build:

I’ve been on a quest for while now trying to build a retropie handheld that was functional but didn’t break the bank. So far I’ve made ZeroBoy – A poor man’s retropie “portable” and a follow-up ZeroBoy rev C – An improved poor mans retropie portable. These were great but I think I have made a much better system with all the features included.

More details  on Facelesstech blog.

Check out the video after the break. (more…)

App note: Operating voltage ratings for inductors

Posted on Sunday, April 7th, 2019 in app notes by DP | No Comments

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Coilcraft’s app note on why inductor’s voltage ratings are uncommonly mentioned in most applications. Link here (PDF)

Voltage ratings are often specified for many electronic components, including capacitors, resistors and integrated circuits, but traditionally this has been rare for inductors. Recent trends, particularly the introduction of higher voltage rated semiconductor devices, have created a new emphasis on operating voltage as part of the inductor selection process. Inductors once considered optimized for high current, low voltage applications are finding homes in new designs that apply higher voltage stress to the inductor.

App note: Power supply topologies – Forward of Flyback? Which is Better? Both!

Posted on Sunday, April 7th, 2019 in app notes by DP | No Comments

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App note from Coilcraft camparing two recognized power supply topologies. Link here (PDF)

Beatles or Stones? Michael or LeBron? Deep dish or thin crust? Forward or flyback? These are just a few of the age-old questions that have been hotly debated over the years, people arguing their opinions with great vigor. But, the truth is, most of the time the answer is both, due to the merits of each.

In this article, we will focus on forward or flyback. We’ll discuss the characteristics of active clamp forward and continuous conduction flyback isolated power supply topologies and demonstrate the design and performance trade-offs of each using two telecom-oriented power supplies as examples.

HX711 load cell amplifier library for AVR ATmega

Posted on Friday, April 5th, 2019 in AVR, library by DP | No Comments

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A HX711 load cell library for AVR ATmega:

HX711 is a precision 24bit ADC IC designed for weigh scales and industrial control applications to interface directly with a bridge sensor.
A load cell is a transducer that is used to create an electrical signal whose magnitude is directly proportional to the force being measured.
The library you can find here is usefull to implement a weigh scale using the HX711.

More details on Davide Gironi’s blog.

Check out the video after the break. (more…)

ESP32 DHT11/DHT22 web server – Temperature and humidity using Arduino IDE

Posted on Wednesday, April 3rd, 2019 in Arduino, tutorials by DP | No Comments

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A how-to on building an asynchronous ESP32 web server with the DHT11 or DHT22 that displays temperature and humidity using Arduino IDE.

More details on Random Nerd Tutorials.

Check out the video after the break.

(more…)

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, April 2nd, 2019 in Free PCBs by DP | No Comments

BP

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.

Qi wireless power receiver from scratch

Posted on Tuesday, April 2nd, 2019 in AVR, DIY by DP | No Comments

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Vinod made a Qi wireless power receiver using Attiny13, that is available on GitHub:

I have only two aims while trying this. The receiver should get powered by the transmitter continuously. I should be able to control the power received by adjusting the error packets, in my case I am trying to keep received voltage always 10v.
There are lot more but I am only interested in this two features for now, so I will not be following the complete Qi specs described on the WPC documents, by the way, it worked for me without any issue. This is purely experimental.

See the full post on his blog.

Check out the video after the break. (more…)

Teardown of a Spex HS1000 monochromator controller

Posted on Monday, April 1st, 2019 in Teardowns by DP | No Comments

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Kerry Wong did a teardown of a SPEX HS1000 monochromator/spectrometer controller:

Monochromator is one of those things that has always fascinated me. Over the years, I have done quite a few experiments (I, II, III) with an EP200Mmd monochromator and it was a lot of fun. Because monochromators are such highly specialized equipment, decent ones are hard to come by at reasonable prices second hand. So my strategy has been to scour eBay once a while and pick up bit and pieces whenever I can.

See the full post on his blog.

Check out the video after the break. (more…)

App note: Replacing traditional optocouplers with Si87xx digital isolators

Posted on Sunday, March 31st, 2019 in app notes by DP | No Comments

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Digital isolator from Silicon Labs app note shows pin compatible plus high performance replacment of incumbent optoisolators, link here (PDF)

Opto-couplers are a decades-old technology widely used for signal isolation, typically providing safety isolation, signal level shifting, and ground loop mitigation. They are commonly used in a wide range of end applications, including data communication circuits, switch mode power systems, measurement and test systems, and isolated data acquisition systems. Optocouplers have several weaknesses, including parametric instability with temperature and device aging, significant internal parasitic couplings, long propagation delay times, narrow operating temperature ranges, and relatively low reliability.

Today’s advanced CMOS signal isolation products offer better timing performance, higher reliability, and lower power consumption compared to optocouplers and are capturing sockets traditionally held by optocouplers. However, converting to CMOS isolation devices has, most often, required circuit changes and PCB modifications that cost money and create design risks, until now.

App note: Introduction to gapped clocks and PLLs

Posted on Sunday, March 31st, 2019 in app notes by DP | No Comments

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App note from Silicon Labs on the introduction of gapped clocks, how they can be used in network timing, and their impact upon phase locked loop (PLL) technology. Link here (PDF)

Gapped clocks are periodic clock signals of a single clock frequency that have clock pulses removed from their stream. Well-formed gapped clocks do not have reduced width pulses (known as runt pulses). Rather, each individual clock pulse is either completely present or completely absent.

miniduino USB

Posted on Thursday, March 28th, 2019 in Arduino, open source by DP | No Comments

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Boris Landoni  writes about a new open source project, the miniduino USB:

A small Arduino board with minimal hardware but with access to all I/Os, just like the Nano and equipped with PCB-integrated, direct-insertion USB connector: it is basically an Arduino Pen Drive.

More details on Open Electronics project page.

Programmable light controller

Posted on Monday, March 25th, 2019 in AVR by DP | No Comments

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Dilshan Jayakody published a new build:

The main objective of this project is to design a maintenance free and low-cost light which automatically turns on and off at the predetermined time of the day.
To meet the above requirement I designed this controller using ATmega8 MCU and DS1307 RTC. The driver stage of this light controller is intended to work with commonly available 7W LED modules.

More details  on his blog.

App note: Miniature, precision negative reference requires no precision resistors

Posted on Sunday, March 24th, 2019 in app notes by DP | No Comments

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App note from Maxim Integrated creating voltage negative reference from charge-pump inverter plus positive voltage reference combo. Link here (PDF)

This application note discusses how to build a negative voltage reference without using external resistors or a negative supply by simply combining a simple charge-pump inverter and a positive output voltage reference.

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