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Arduino controlled Dual Mono AK4490 DAC (part 1)

Posted on Thursday, November 16th, 2017 in Arduino, DIY by DP | No Comments

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This article is the first of a series detailing the design and build process of an Arduino controlled Dual Mono AK4490 DAC by DimDim:

The design goal was to do a dual mono design so as to maximize SNR and channel separation. A 4-layer PCB design was chosen so as to have a very solid, low impedance ground plane as well as proper power and signal planes. The I2S, audio signals and power after the local LDO regulators are routed on the top layer, the 2 middle layers are ground and power planes, and the bottom layer serves to route I2C signals and some power lines.

See the full post here, Dimdim’s blog.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, November 14th, 2017 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.

Schottky diode cross section

Posted on Tuesday, November 14th, 2017 in Teardowns by DP | No Comments

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The cross section of a 1N5817 20V 1A rectifier diode from Electronupdate.

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

Free PCB Sunday: Pick your PCB

Posted on Sunday, November 12th, 2017 in Free PCBs by DP | 17 Comments

BP-600x373

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:

(more…)

App note: Adjustable gain with a current sensing

Posted on Sunday, November 12th, 2017 in app notes by DP | No Comments

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Application note from STMicroelectronics for fine tuning gain on current sensing amplifier. Link here (PDF)

This application note explains how to use current sensing amplifiers with series resistors on the sense inputs. This approach is especially useful for applications where the gain must be adjusted.

App note: Intelligent power switches for 48 V battery applications

Posted on Sunday, November 12th, 2017 in app notes by DP | No Comments

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Application note on controling Intelligent Power Switches (IPS) from STMicroelectronics. Link here (PDF)

For the last 15-20 years, the automotive electronics market has been moving from electromechanical relays to solid state components for driving all kind of loads.

It is obvious why: solid state components are smaller in size, lighter, silent, easy to mass produce because they are housed in SMD packages, and they boast an unrivaled number of switching activations. On top of this, the solutions based on silicon components have a much higher electrical efficiency and offer useful types of diagnostics such as short-circuit, overload and thermal protections, they can supply an actual image of the current flowing into the load, and so on. In fact, they are called “Intelligent Power Switches (IPS)” or “Smart Power MOSFETs” for good reasons. The key “switching” element is an N-MOSFET, with the relevant charge pump. Around the N-MOSFET, logic interfaces and other elements contribute to the protection of the MOS and they generate and manage diagnostic data.

Teardown of a BK precision 1696 programmable switching power supply

Posted on Thursday, November 9th, 2017 in power supply, Teardowns by DP | No Comments

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Kerry Wong did a teardown of a BK Precision 1696 programmable switching power supply:

My original plan was to find a replacement LCD and restore the unit to its original full functionality. But the LCD used in this unit is likely specifically made for the 169X series of power supplies and through some initial research I realized it would be extremely difficult to get hold of unless I could find a donor unit with a functional LCD inside. After I received the power supply, I realized that it had more issues than just the broken LCD itself. During my initial testing, I found that the output would not reach higher than 10 to 11 volts even with the over voltage protection set to the maximum value (20.5V). So clearly I have more homework to do, and for the time being let’s simply strip it down and see what’s inside.

See the full post on his blog.

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

Fascinating details of Waveshare e-paper displays

Posted on Thursday, November 9th, 2017 in part review by DP | 1 Comment

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Erich Styger has a nice write-up on Waveshare e-paper displays:

I have used E-Ink displays in projects three years ago, but from that time the technology has greatly evolved. That time displays were hard to get, expensive and difficult to use. Now things seem to change with e-ink displays available to the maker market :-). I’m able to get a 128×296 pixel e-paper display for $10! And for little more money I can have displays with black/white/red colors!

More details at MCU on Eclipse homepage.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, November 7th, 2017 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.

How to configure I2C sensors with Arduino

Posted on Tuesday, November 7th, 2017 in Arduino, how-to by DP | No Comments

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Edward Mallon writes:

I’ve spent the last year in the ‘uncanny valley’ of the Arduino. That’s the point where you understand the tutorials at Arduino.cc, but still don’t get much from the material on gitHub because trained programmers would never stoop to using the wire.h library when they could just roll their own in native C++ using the avr-g++ compiler.  The problem with establishing sensor communication at the level of the TWI peripheral inside the AVR is that there are so many fiddling details to keep track of that it quickly overruns the 7±2 things this average human can hold in his head at one time: Computers aren’t the only things that crash after a buffer overflow!  So this post is meant to be a chunking exercise for beginner-intermediate level people like myself who want to get a new sensor working using the standard IDE.  I’ve tried to distill it all down to things that I run into frequently, but there’s still a lot of material here:  So pour yourself a cuppa before diving in…

More details at Arduino based underwater sensors blog.

App note: Position sensing technologies in automotive applications

Posted on Sunday, November 5th, 2017 in app notes by DP | No Comments

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An Autopad(TM) sensor from TT Electronics provides a new non contact position sensing. Link here (PDF)

Automotive design engineers are continuously seeking components that offer performance and flexibility beyond those of conventional position sensing technologies. Further still are the requirements that these devices be versatile and adaptable to a wide range of applications. This demand has led to the need for devices incorporating the best design elements from conventional contacting and non-contacting sensor technologies.

Free PCB Sunday: Pick your PCB

Posted on Sunday, November 5th, 2017 in Free PCBs by DP | 12 Comments

BP-600x373

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:

(more…)

App note: Thermal management basics and its importance for LED luminaire performance and cost

Posted on Sunday, November 5th, 2017 in app notes by DP | No Comments

an_tt_electronics_LED_luminaire_thermals

Article about thermal management on LED luminaire from TT Electronics. Link here (PDF)

LED luminaires are being marketed today as an alternative lighting technology that reduces power consumption and maintenance costs for commercial and residential installations. Thermal management has a significant impact upon the lifetime, performance and cost of an LED luminaire. Without proper application of thermal management design principles, the potential benefits of solid state lighting and its ability to be successfully marketed will be reduced.

Free PCB coupon via Facebook to 2 random commenters

Posted on Friday, November 3rd, 2017 in Free PCBs by DP | 2 Comments

BP

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:

(more…)

Simpleceiver Plus version 2 SSB transceiver

Posted on Thursday, November 2nd, 2017 in DIY, RF by DP | No Comments

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An update on Pete Juliano’s (N6QW) Simpleceiver project we covered previously:

Version 2 — What is it? V2.0 is the Simpleceiver Plus SSB Transceiver Architecture with the following changes:

  • A GRQP Club 9.0 MHz Crystal Filter is used in place of the homebrew 12.096 Four Pole Filter. This gives the advantage of acquiring the matching crystals for the BFO and with a 5 MHz Analog VFO you can have a two band rig (20 meters or 80 Meters). The only change required is the appropriate matching Band Pass and Low Pass Filters. A couple of relays and a toggle switch will put you on either band. So a big plus here. Or you can leave it on 40 Meters.
  • Compacting the rig in physical size. I have used two 4 X 6 inch PC Board and fit all of the circuitry on these two boards which will then be stacked upon each other.

See the full post on his blog.

Dirty Cables price increases and lead times

Posted on Thursday, November 2nd, 2017 in cables, DirtyPCBs.com by Ian | No Comments

DirtyPCBs

Its really hard to convince Huaqiangbei market suppliers to cooperate on a project until you can prove value by making a bunch of orders. Our approach is to guestimate a price at DirtyPCBs, send through a few months of orders, and then ask if they’d like to cooperate with us. Generally this will open doors to closer integration like getting full price lists.

After a few months of running Dirty Cables we looked at our overall order history. On 75% of orders we lost anywhere from $5 to $500. This was totally expected and part of convincing suppliers to give us full pricing details.

Our current supplier makes outstanding cables, but getting a quote is still like pulling teeth and takes ages. They also seem completely uninterested in providing a full price list. We’re in the market today shopping for a new supplier, but in the meantime prices on most connectors have been doubled or more based estimates from the first few months of data. It would also be fair to say lead time is currently 10-20 days, more on large or complicated orders.

Since a lot of the loss/expense is in the low volume orders of 100 cables, we need to compensate with bigger discounts on high volume orders. Connector prices are easy to update in the back end, but volume discounts require a site update that will come towards the beginning of next week. If you’re placing a large order and think the price is too high, please contact us for a more accurate quote.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, October 31st, 2017 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.

PS2-TTLserial adapter for RC2014 and MIDI

Posted on Monday, October 30th, 2017 in AVR, hacks by DP | No Comments

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Dr. Scott M. Baker published a new build:

The original reason for this project is that I wanted to build a standalone RC2014 with keyboard and display. There is an official RC2014 serial keyboard, but I find it a little inconvenient for my big fingers and poor eyesight. I have plenty of old PS/2 keyboards laying around, so I figured I’d rig up a microcontroller to convert the PS/2 keyboard interface into a TTL-level serial interface that could be plugged directly into the RC2014’s serial port.
Along the way, I discovered that the very same circuit would make an interesting project to turn a PS/2 keyboard into a simple MIDI controller. So I adapted the circuit for that purpose as well.

See the full post on his blog.

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

DIY through hole plating of PCBs

Posted on Monday, October 30th, 2017 in DIY, PCBs by DP | 1 Comment

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Jan Mrázek documented his experience experimenting with DIY through-hole plating of PCBs:

I’ve been thinking about though hole plating for several years. The general procedure is simple – you have to activate non-copper surfaces (make them conductive) and then you apply standard electroplating procedure. You can find many tutorials on the internet, however, most of the require hard-to-get chemicals for the activation solution. Few weeks ago, I noticed that the local electronic component supplier had started to sell Kontakt Chemie Graphit – a conductive paint. It’s basically a colloidal graphite in an organic solution. It is supposed to be used for making surfaces conductive to prevent static electricity discharges. This could be perfect for activation of the non-copper surfaces! So I gathered all the necesery chemicals and equipment and made a test run.

More info at mind.dump() blog.

ESP8266 Deep Sleep with Arduino IDE

Posted on Monday, October 30th, 2017 in Arduino, tutorials by DP | 2 Comments

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Rui Santos has written a great guide shows us what’s Deep Sleep and how to use it with the ESP8266 in the Arduino IDE.

With most of the ESP8266 modules, you can’t change the hardware to save power, but you can write software to do it. If you use the sleep functions with the ESP8266, it will draw less power and your batteries will last longer. In this guide, we’re going to talk about Deep Sleep with the ESP8266.

See the full post on his blog, Random Nerd Tutorials.

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

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Recent Comments

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