Categories

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, February 19th, 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.

Variable Frequency Drive

Posted on Tuesday, February 19th, 2019 in hacks by DP | No Comments

20190202_AntriebSchaublin-600

Lukas Fässler over at Soldernerd wrote an article detailing his homemade VFD drive for his Schaublin 102 lathe.

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

Outdoor UV index sensor

Posted on Tuesday, February 19th, 2019 in how-to, sensors by DP | No Comments

Outdoor UV index sensor

A detailed instructions of how to build this outdoor UV index and ambient light sensor from Mare & Gal Electronics:

The VEML6075 senses UVA and UVB light and incorporates photodiode, amplifiers, and analog / digital circuits into a single chip using a CMOS process. When the UV sensor is applied, it is able to detect UVA and UVB intensity to provide a measure of the signal strength as well as allowing for UVI measurement.

Semiconductor radioactivity detector – part 2

Posted on Tuesday, February 19th, 2019 in hacks, how-to by DP | No Comments

IMG_3252-600

Robert Gawron has been working on a radioactivity detector, that is available on GitHub:

There are many ways to measure radioactivity level, semiconductor detectors sense interactions between ionizing radiation and p-n junction. Because in hobbyist area most popular are Geiger-Muller based detectors (in short: not a semiconductor but lamp based devices), I think it’s a cool idea to take a look at this approach.
In this post I will present such home-made sensor and a set of software to parse collected results.

See the full post on his blog. Be sure to see Part 1 here.

NFC antenna tuning without a VNA

Posted on Monday, February 18th, 2019 in PCBs by DP | No Comments

img_20181025_215846-600

Fred writes:

Recently I started work on a new board. This one will be a front door entry system, so I decided to go with something that could read my NFC implant but also had a numeric keypad for the kids (and anyone else) to use. Not everyone wants to be chipped. Crazy, isn’t it? I’ll write more up on the board when it gets closer to completion, but for this post I’m going to concentrate on a small PCB antenna that’s intended for use with a tiny implanted tag. I’ve successfully used a wirewound inductor before, but I decided it was time to try a PCB trace antenna. This is the most common way to make an NFC reader, but nobody seems to have tried to tune one for an implant – probably because it means it will be worse at reading larger tags. Anyway, this is about creating a small PCB antenna and more importantly tuning it so that it read well.

Check out the video after the break.

More details on 0xFRED blog.

(more…)

App note: Securing vibration motor leads and wires

Posted on Sunday, February 17th, 2019 in app notes by DP | 1 Comment

an_precisionmicrodrives_ab009

App note from Precision Microdrives on how to properly connect wires on to vibration motors for reliability. Link here

Vibration motors require electrical power, which must be delivered by wires or PCB tracks to the motor. Precision Microdrives vibrating motors are available in a range of connector forms. From stock, they are available with factory installed leads, terminals, PCB solder pins, or as PCB SMT / SMD options. Solder pins and SMT motors have the advantage of being mounted directly onto the PCB which simplifies the connection process.

App note: Vibration Motors – Voltage Vs Frequency Vs Amplitude

Posted on Sunday, February 17th, 2019 in app notes by DP | No Comments

an_precisionmicrodrives_an029

All about vibration motors and how its frequency and amplitude be controlled in this app note from Precision Microdrives. Link here

We’re often asked how to adjust the vibration amplitude or frequency of our various vibration motors. In this article, we’ll look at how simple it is, why it can be useful, and how we can predict the behaviour of a motor using the driving voltage and Typical Performance Characteristics graph.

An Arduino version of Brooks Shera’s GPSDO

Posted on Monday, February 11th, 2019 in Arduino by DP | No Comments

IMG_2430-600

Jeff (aka K6JCA) has a great write-up on implementing the Brooks Shera Phase-Locked Loop GPSDO on an Arduino Platform:

This blog post is a continuation of my two earlier GPSDO blog posts. The first one (from a few years back) details a simple Frequency-Locked Loop GPSDO design, based around an Arduino processor. The second (more recent) blog post discusses simulating Brooks Shera’s GPSDO algorithm (from the July, 1998 issue of QST) using The MathWorks Simulink program.
This third blog posts describes my modification of my original Frequency-Locked Loop (FLL) GPSDO to be a Phase-Locked Loop (PLL) GPSDO, and it includes the hardware schematics, Simulink models, and the Arduino code I wrote to implement Brooks Shera’s GSPDO algorithm on an Arduino processor.

More details on K6JCA blog.

App note: Ceramic resonators

Posted on Sunday, February 10th, 2019 in app notes by DP | No Comments

an_abracon_ceramic_resonators

All about ceramic resonators app note from Abracon. Link here (PDF)

Why Ceramic Resonators? Ceramic resonators stand between quartz crystals and LC/RC oscillators in regard to accuracy. They offer low cost and high reliability timing devices with improved start-up time to quartz crystals.

App note: MELF resistors – The world’s most reliable and predictable, high-performing film resistors

Posted on Sunday, February 10th, 2019 in app notes by DP | No Comments

an_vishay_melfre

App note from Vishay on why MELF resistors are so successful and has no alternative in today’s application. Link here (PDF)

For more than 25 years, Vishay’s MELF resistors have successfully met the demanding requirements of the automotive industry. They offer superior SMD resistor performance in terms of accuracy, stability, reliability, and pulse load capability. The cylindrical construction of MELF devices provides an optimal power rating and pulse load capability related to the mounting space. Continuous development has led to improved long-term stability and moisture resistance, and allows high-temperature operation to + 175 °C.

Serial Star, a 4 in 1 USB serial and I2C converter

Posted on Friday, February 8th, 2019 in PCBs, USB by DP | No Comments

seriaLstar_v1.0-001-624x468-600

Jesus Echavarria published a new build:

Here’s one of the last board I design the last year. On 2016, I develop the Dual USB Serial and I2C Converter board. Although this board works fine, it has a couple of lacks. First one, is that to use the both converters, you need two free USB ports. Is a minor problem today with USB hubs, but you need the hub and also two USB wires. And the other problem is that this board uses mini-USB connectors. Of course today you can still find it, but aren’t as common as the micro-USB wires. For this two reasons, I decide to upgrade the board, add the micro – USB connector and put a USB hub inside it. Because I choose a 4-port USB hub, I use also 4 USB serial converters. With some addons, you can select power supply value (5V, 3V3), serial levels (TTL, RS232) and GPIO functions in an independent way for each converter. So, let’s see how works this USB Serial Star, a 4 in 1 USB to Serial and I2C Converter.

More details on Designing Electronics in Spain blog.

Teardown of a Piezoelectric vibrating gyroscope

Posted on Wednesday, February 6th, 2019 in Teardowns by DP | No Comments

ENC03JB-600

Kerry Wong did a teardown of an old analog piezoelectric vibrating gyroscope:

Gyroscopes nowadays are based on micro-electro-mechanical systems (MEMS) technology. They are low cost and extremely miniaturized. A device combing both a three-axis gyroscope and a three-axis accelerometers (sometimes these devices are referred to as 6DOF devices) such as the MPU-6500 for example can be had in a QFN package as small as 3 mm x 3 mm and under 1 mm in height. Before these MEMS devices gained mainstream popularity however, larger piezoelectric vibrating gyroscopes were used in many consumer electronics devices.

See the full post on his blog.

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

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, February 5th, 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.

Solar powered weather station

Posted on Tuesday, February 5th, 2019 in DIY by DP | No Comments

Solar Powered Weather Station-600

Antalife has written an article detailing the build of his a solar powered weather station:

To expand my microcontroller and programming knowledge I have decided to try and make a Solar Powered Weather Station. My goal is to record parameters like:
*Temperature
*Humidity
*Air pressure
*Air quality (something to do with CO or CO2)
I then hope to send (wirelessly) the data to a base station and log/display it on a simple website. To make things interesting I also aim to power the data gathering station from a large supercapacitor (~100F), and in keeping with my solar tradition the supercapacitor will be charged from a solar-cell.

See the full post on his blog.

Free PCB Sunday: Pick your PCB

Posted on Sunday, February 3rd, 2019 in Free PCBs by DP | 4 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: Understanding the characteristics of Li-ion batteries and Richtek power management solutions

Posted on Sunday, February 3rd, 2019 in app notes by DP | No Comments

an_richtek_an023

App note from Richtek on how to work with Li-ion batteries properly. Link here

Lithium-ion/polymer rechargeable batteries, which have been widely used today, have distinguished properties, but are very delicate and have to be used with extreme care. Improper use of Li-ion batteries will bring about catastrophic consequences. The incidences of burning and explosions of Li-ion batteries have often been heard. Carefully understanding their properties and adopting a right battery management method is most essential for making good use of Li-ion batteries.

App note: Power IC solutions for IoT / Portable / Wearable / Battery-Powered applications

Posted on Sunday, February 3rd, 2019 in app notes by DP | No Comments

an_richtek_SG012_03

A tidy and organized power solution list from Richtek. Link here (PDF)

Simple I2S stereo decoder with amplifier

Posted on Friday, February 1st, 2019 in DIY by DP | No Comments

46827111321_0a7011d921_z-600

Dilshan Jayakody published a new build:

In this project we build simple I2S stereo decoder with amplifier. To decode I2S data we use Princeton Technologies PT8211 16bit DAC. KA2206 audio power amplifier is used as driver stage of this system.
Structure of this I2S amplifier is self-explanatory from the schematic. We select PT8211 and KA2206 combination due to lower cost and availability. Unfortunately PT8211 DIP package is not available in local market and we use SO package in our prototype. We design PCB for the DIP packages, and therefore we solder PT8211 SO package to PCB using “SO8 to DIP8” converter.

See the full post on his blog.

A transmit converter (and amplifier) for 630 and 2200 meters

Posted on Wednesday, January 30th, 2019 in DIY, RF by DP | No Comments

TX_Conv_Internal_1a

KA7OEI has a great write-up on building a transmit converter for 630 and 2200 meters:

As the name implies, a transmit converter takes another frequency – such as that produced by a conventional HF transceiver – and converts it to another frequency.  In my case I use an FT-817 – a low-power (5 watt) all-mode, all-band transceiver that is a favorite for VHF, UHF and microwave enthusiasts that use transverters.  Because of its small size, feature set and already-low output power, it is a natural to be used in this application.

See the full post on his blog.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, January 29th, 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.

Next Page »

Recent Comments

  • lostengineer: hahaha an entire article just saying to heat-shrink your wires or glue them if they might move around a lot. When did common sense die?
  • readybrek: They're tasty tasty very very tasty... they're very tasty.
  • hli: Sunday++
  • Chamod: Check on your buddy. Make sure they don't forget their lunchbox.
  • Kurt: But February made me shiver With every paper I'd deliver Bad news on the doorstep I couldn't take one more step