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ถูกปรับปรุง 13 hours 47 min ก่อน

Minimal ATSAMD21 computer

ศุกร์, 05/10/2019 - 06:56

Johnson Davies shared detailed instructions of how to build an ATSAMD21-based computer on a prototyping board using a 32-pin ATSAMD21E:

If you’re looking for something more powerful than the ATmega328 in the Arduino Uno a good choice is the ATSAMD21. This is an ARM Cortex M0+ processor with up to 256KB flash memory, 32KB RAM, and a 48MHz clock, so it’s substantially better equipped than the ATmega328. In addition it has a USB interface built in, so there’s no need for a separate chip to interface to the serial port.
Arduino have designed several excellent boards based on the ATSAMD21, such as the Arduino Zero or smaller-format MKRZERO. However, these boards are an expensive way to use an ATSAMD21 as the basis for your own project, and they probably include many features you don’t need.

More details on Technoblogy.

#FreePCB via Twitter to 2 random RTs

พุธ, 05/08/2019 - 06:30

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.

Arduino interface for TFA9842AJ power amplifier

อังคาร, 05/07/2019 - 21:54

Dilshan Jayakody writes, “I tested a couple of TFA9842AJ based amplifiers in the last couple of years. The main reason I liked TFA9842AJ is its simple, clean design, wide operating voltage, and high-quality bass-rich audio output.  Thanks to it’s built-in DC volume control circuit this audio amplifier can easily interface with MCU. In this article, we provide a generic TFA9842AJ module which works with most of Arduino boards, MCUs and SOCs.”

See the full post in his blog.

App note: 3V DACs used in ±10V applications

จันทร์, 05/06/2019 - 00:00

Boosting DAC’s output to drive larger voltage tackled in this app note from MAXIM Integrated. Link here (PDF)

Many modern systems have the majority of their electronics powered by 3.3V or lower, but must drive external loads with ±10V, a range that is still very common in industrial applications. There are digital to analog converters (DACs) available that can drive loads with ±10V swings, but there are reasons to use a 3.3V DAC and amplify the output voltage up to ±10V.

App note: Tire pressure monitor system

อาทิตย์, 05/05/2019 - 20:00

NXP Semiconductor’s implementation of Tire pressure monitor (TPM) system. Link here (PDF)

The Tire Pressure Monitoring System Reference Design consists of five modules: four tire modules and a receiver module. The tire modules consist of the MPXY80xx, the RF2, a battery, several discrete components, and a printed antenna. The receiver module has the MC33954, the KX8, five LEDs to display the status, a battery, a power supply connection, and an RS-232 serial interface.

Semiconductor radioactivity detector: part 3

เสาร์, 05/04/2019 - 21:51

Robert Gawron has made a new version of his radioactivity detector project and wrote a post on his blog detailing its assembly:

In this post I will present a new hardware version of my sensor, older versions are described in part I and part II. In comparison to the previous one, sensitivity is roughly x10 more sensitive.
In previous version, tin foil window for photodiodes was very close to the BNC sockets and because enclosure was small, it was hard to place a sample close enough. Not it’s better, however, if I would choosing again, I would use metal enclosure similar to those used in PC oscilloscopes and put BNCs on front panel, power socket on rear panel and tin foil window on top. This would allow me to easier access for debugging- now I have to desolder sockets to get to photodiodes or to bottom side of PCB.

See the full post on his blog.

The Nixie tube filadometer – a Nixie tube filament meter for your 3D printer

พฤ, 05/02/2019 - 22:17

Dr. Scott M. Baker made a Nixie tube filament meter for his 3D Printer:

First, I decided to upgrade from the Raspberry Pi Model B to a more recent Raspberry Pi Zero W that I had on hand. Wired Ethernet is so ~ 2013 after all, and wireless would be a lot more convenient. Next, I designed a 3D printed case for it, as my old laser-cut-acrylic-and-glue case also looked very dated. Finally, I replaced the software with a new program designed to poll the data from my octoprint server. In less than an afternoon, I had turned the old temperature/humidity display into something useful.

See the full post on his blog.

Check out the video after the break.

Open Trickler: The DIY smart powder trickler

พุธ, 05/01/2019 - 21:53

Eric Higgins has a nice build log on his Open Trickler project a bluetooth-enabled smart powder trickler from off-the-shelf parts for under $60:

Fundamentally, this is not a hard problem to solve. Read the value from the scale, run a motor that moves powder into the scale, turn off the motor when the scale reads the target weight. As with many projects, the devil’s in the details and there was plenty of trial-and-error during the development process to reach a working prototype.
In this project, a Raspberry Pi is used to read the weight from the scale and run a small vibration motor (like those in mobile phones) to trickle powder. An app on your phone or tablet connects to the Raspberry Pi over Bluetooth, and is used to set the target weight and start/stop the automatic trickling process.

See the full post on Ammolytics blog.

Check out the video after the break.

#FreePCB via Twitter to 2 random RTs

พุธ, 05/01/2019 - 05:00

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.

Teardown of a LogiMetrics A300/S traveling wave tube amplifier

อังคาร, 04/30/2019 - 21:42

 LogiMetrics A300/S TWTA teardown by Kerry Wong:

I just picked up a LogiMetrics A300/S 2 GHz to 4 GHz (S band) traveling wave tube amplifier (TWTA) on eBay. I had done an extreme teardown of an HP 493A TWTA a while ago and it was quite fascinating to see what’s inside of a TWT. This LogiMetrics A300/S was made from the late 70’s and unlike the HP 493A it was made entirely using solid state devices (e.g. transistors and ICs), the TWT itself of course remains a vacuum tube.

See the full post on his blog.

Check out the video after the break.

16 x 2 LCD controlled via power line

จันทร์, 04/29/2019 - 23:47

Vinod blogged about a 16×2 LCD with data over power line:

Then I just thought why even 1 wire for data? Because we can easily multiplex the 1 wire data line with the Vcc line by keeping a diode + capacitor combination towards the LCD power supply pin. I am using an arduino board to do the serial to parallel conversion + some packet parsing and lcd backlight brightness control. I am not a huge fan of Arduino but for this simple proof of concept, I don’t want to bring out a Makefile folder with muliple files. I picked the Arduino UART RX as the serial receiver. RX pin is connected directly to the input Vcc, but before the schottky diode.

See the full post in his blog.

Check out the video after the break.

App note: Crystal oscillator troubleshooting guide

จันทร์, 04/29/2019 - 01:35

App note from NXP Semiconductors dealing with oscillators in microcontrollers. Link here (PDF)

Most microcontrollers can use a crystal oscillator as their clock source. Other options include external canned oscillators, resonators, RC oscillators, and internal clocks. The main advantages of a crystal oscillator are frequency accuracy, stability, and low power consumption. However, high reliability is needed to fully benefit from these advantages.

App note: Active cell balancing in battery packs

อาทิตย์, 04/28/2019 - 20:00

Cell balancing implementation from NXP Semiconductors. Link here (PDF)

Batteries made of multiple cells connected in series are often used as a power source for common electronic devices. In multicell battery chains, small differences between the cells (due to production tolerances or operating conditions) tend to be magnified with each charge or discharge cycle. In these situations, weaker cells are overstressed during charging, causing them to become even weaker, until they eventually fail and cause a premature failure of the whole battery. Cell balancing is a way of compensating for these weaker cells by equalizing the charge on all the cells in the chain, thus extending the battery life.

Aweigh: the open-source alternative to GPS

ศุกร์, 04/26/2019 - 21:12

A team of student designers and engineers from the RCA and Imperial College have developed a substitute for GPS that does not rely on satellites, called Aweigh:

Aweigh is an open navigation system that does not rely on satellites: it is inspired by the mapping of celestial bodies and the polarized vision of insects. Ancient seafarers and desert ants alike use universally accessible skylight to organize, orient, and place themselves in the world. Aweigh is a project that learns from the past and from the microscopic to re-position individuals in the contemporary technological landscape.

Via Open Electronics.

Check out the video after the break.

#FreePCB via Twitter to 2 random RTs

พุธ, 04/24/2019 - 06:45

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.

Building a Jones Push-Pull Oscillator

พุธ, 04/24/2019 - 06:43

Steve (VE7SL) has built a Jones Power-Oscillator using a pair of 6L6s and wrote a post on his blog detailing its assembly.

Homebrew DMX-controlled RGB LED light

อังคาร, 04/23/2019 - 06:00

Glen has written an article detailing his homebrew DMX-controlled RGB LED light:

This project is a small DMX-512 controlled, color-changing RGB LED light. The light can be controlled via the DMX512 protocol or it can run a number of built-in programs depending on how the software is configured. The light incorporates an advanced 16-bit PIC24 microcontroller with PWM capabilities, a 3D printed enclosure, a laser cut acrylic lid, a custom switching power supply, and a MEMS oscillator. The light measures roughly 2.25″ square by 1.25″ high. This light is the evolution of my RGB LED light designs that span back over a decade.

Project info on Photons, Electrons, and Dirt blog.

Arduino Shield for CAT M1 and NB-IoT modems

อังคาร, 04/23/2019 - 05:45

Michael Krumpus designed and built an Arduino shield for Nimbelink Skywire CAT M1 and NB-IoT modems, that is available on Github:

Nimbelink has a development kit for use by product developers, but it’s rather expensive. I wanted to try out a Nimbelink CAT M1 modem without the dev kit, and since there are so many hobbyists using Arduinos out there, I wanted to provide a nice Arduino library for the modem. I chose the Nimbelink module based on the Sequans Monarch CAT M1 modem and got to work designing an Arduino shield to hold it.

More details on Nootropic design Project Lab site.

App note: Reduced power dissipation of relay loads

จันทร์, 04/22/2019 - 00:00

Another app note from ON Semiconductors on using PWM technique to reduce power consumed when latching mechanical relays. Link here (PDF)

Integrated circuit driver circuits often use relay loads in their application. Output drivers are a source of power dissipation on the IC. Latching relays can be used to keep sustaining load current at a minimum by engaging and removing drive current, but a PWM system can also preserve reduced power conditions by engaging and reducing duty cycle using standard type relays.

By considering the Maximum Turn−On Voltage and Minimum Turn−Off Voltage specifications typically quoted in the relay electrical specification, your system design can utilize a signal to pull−in and activate the relay followed by a reduced power PWM sustaining signal.

App note: The load switch – Selection and use of ecoSWITCH(TM) products

อาทิตย์, 04/21/2019 - 20:00

ecoSWITCH(TM) from ON Semiconductors offers space saving solution on power distribution system. Link here (PDF)

Load switches play an important part in the management of supply domains and the protection of the loads they supply. Loads switches are often used for power sequencing, standby load leakage reduction, and inrush current control. Integrated ecoSWITCH products deliver an area reducing solution, offering over current protection, load soft start, and extremely low on series resistances of sub − 20 milliohm. This article discusses the primary benefits of load switches, application considerations, and how ecoSWITCH differs from other types of integrated switch offerings. A generic cloud system application and USB power delivery example are presented to demonstrate how the addition of ecoSWITCH solves design challenges such as achieving low quiescent current, local load protection, and startup sequencing.