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Seeed Studio Summer Sale! — Enjoy 10% OFF purchases over $100!

Posted on Wednesday, June 21st, 2017 in News by DP | No Comments

summer22

Enjoy 10% OFF your purchase of $100 or more at Seeedstudio Bazaar!

Let’s celebrate summer time with a screaming deal on Seeedstudio Bazaar! You can enjoy 10% Discount for order product value above US$100.

Promo code:
SEEEDSUMMER

Promotion Time:
From June 13th to June 30th (GMT+8)

The coupon will be expired on June 30th.

Items:
All Bazaar items! (Bundle sales items are excluded.)

Visit Seeed Studio’s promo page for details.

How to: STM32F103C8T6 as an USB device (Virtual serial port / CDC)

Posted on Wednesday, June 21st, 2017 in how-to, USB by DP | No Comments

In this video Hugatry shared detailed instructions of how to use the STM32F103C8T6 as an USB device with virtual serial port:

Cheap STM32F103C8T6 development board
Blue STM32F103C8T6 development boards, also known as “BluePill”, are cheap way to get started with 32bit ARM microcontrollers. The STM32 development board can sometimes be bought for less than $2 and ST-LinkV2 compatible programmer and debugger doesn’t cost much more than that either.
The STM32F103C8T6 has nice amount of flash and RAM, runs at 72MHz and best of all: It has built-in USB. It is possible to program these STM32 boards to act as an USB devices, without “FTDI chip”. In this post and in the embedded video I will teach step by step how to use the STM32F103C8T6 as an USB device, in particular a virtual serial port.

More details at Hugatry’s HackVlog.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, June 20th, 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.

Arduino data logger update

Posted on Tuesday, June 20th, 2017 in Arduino, DIY by DP | No Comments

s-teriminalminiloggerthecavepearlproject-600

An update on Edward Mallon’s Arduino data logger project we covered previously:

If you need a logger with a cheap durable housing, it’s still hard to beat the Dupont-jumper build released in 2016. But sometimes I need more of a bare-bones unit for bookshelf test runs while I shake down a new sensor. I can whip up a breadboard combo in about twenty minutes, but they can stop working if I bump one of the wires by accident. I’ve lost SD cards from this half way through a long term test, and I’ve also run into issues with noise & resistance from those tiny breadboard contact points.
To address this problem I’ve come up with a new configuration that uses a screw-terminal expansion shield originally intended for the Arduino Nano. This requires a modest bit of soldering, and after some practice, between 1-1.5 hours to finish depending on how many “extras” you embed.

Read more details at his blog here.

Free PCB Sunday: Pick your PCB

Posted on Sunday, June 18th, 2017 in Free PCBs by DP | 18 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: How to measure thermal resistance of LED emitters and LED arrays

Posted on Sunday, June 18th, 2017 in app notes by DP | No Comments

an_lumileds_wp23

Another white paper from Lumileds about LED thermal resistance. Link here (PDF)

Thermal performance is the most critical factor of a well-designed LED lighting system. A lighting system with proper thermal design has higher efficacy, meaning more light can be extracted using less energy, and better long term reliability.

App note: Flash for “Selfies”

Posted on Sunday, June 18th, 2017 in app notes by DP | 1 Comment

an_lumileds_wp26

Effective front facing camera flash discussed in this white paper from Lumileds. Link here (PDF)

Smartphones are ubiquitous in everybody’s daily lives, a trend that shows no sign of slowing. A key component of the smartphone is the camera, which has gained market share over Digital Still Cameras due to its convenience.

As the demand for smartphone cameras increases, sensor makers are continuously working to improve the resolution and while 20MPix capability gained in importance for the main camera of the smartphone, the resolution race has begun for the front camera. With the rise in popularity of “selfies” and the 5 to 8 Mpix resolution for the front camera, it is not surprising that camera flash is starting to be more readily implemented for front cameras also. However, to make a successful front flash that captures an ideal “selfie,” there are certain illuminance requirements and shorter flash pulses that are recommended.

Free PCB coupon via Facebook to 2 random commenters

Posted on Friday, June 16th, 2017 in Free PCBs by DP | No 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…)

DIY robot design

Posted on Thursday, June 15th, 2017 in robotics, tools by DP | No Comments

robo-design2_853x234-min

A computational abstractions for interactive design of robotic devices by Ruta Desai, Ye Yuan and Stelian Coros from Carnegie Mellon University’s Robotics Institute:

We present a computational design system that allows novices and experts alike to easily create custom robotic devices. The core of our work consists of a design abstraction that models the way in which electromechanical components can be combined to form complex robotic systems. We use this abstraction to develop a visual design environment that enables an intuitive exploration of the space of robots that can be created using a given set of actuators, mounting brackets and 3d-printable components. Our computational system also provides support for design auto-completion operations, which further simplifies the task of creating robotic devices. Once robot designs are finished, they can be tested in physically simulated environments and iteratively improved until they meet the individual needs of their users.

Full details at cmu.edu.

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

Display Arduino analog input using LabVIEW

Posted on Tuesday, June 13th, 2017 in how-to by DP | 1 Comment

featured-image

Zx Lee shared detailed instructions of how to display the Arduino measurements using LabVIEW:

To get started, I will explain what is actually going on in Arduino. In this project, I am using an Arduino Nano to acquire signals and send the data to PC. As mentioned earlier, two analog input channels (A0 & A1) will be used to measure input signals. To ensure an accurate measurement is performed at fixed sample rate, the Arduino is configured to wait the predefined interval before taking a measurement and send to PC serially. The concept used is similar to the BlinkWithoutDelay example in Arduino. The benefit of using this method is that there is a while loop that always checks if it has crossed the desired interval. If it is reached, it will take the measurement, else it will skip and you can make it to work on other task.

More details at his blog here.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, June 13th, 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.

Raspberry Pi soft power controller – the circuit

Posted on Tuesday, June 13th, 2017 in R-Pi by DP | 5 Comments

pics-RPSPC-Prototype-600

James Lewis has been working on a Raspberry Pi soft power controller, that is available on github:

The RetroPie project enables retro-gaming with a Raspberry Pi. All of the Pi models have enough computing power to emulate the major 8-bit and 16-bit computers of the 80s and 90s. With the Pi 3 I have even been able to play PS1 games with no problem. My current project is to put my Raspberry Pi running RetroPie into an old Super Famicom (SFC), or SNES, case. The catch? I want the original SPST power switch to work. And by work, I mean allow the Raspberry Pi to shutdown properly when the switch goes into the off position.  To accomplish this task, I am building a Raspberry Pi soft power controller.

More details at baldengineer.com.

Free PCB Sunday: Pick your PCB

Posted on Sunday, June 11th, 2017 in Free PCBs by DP | 26 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: DAC ICs: How many bits is enough?

Posted on Sunday, June 11th, 2017 in app notes by DP | 2 Comments

an_ad_AN-327

A very old application notes from Analog Devices that tells about Nyquist Theorem, sampling rate and quantization used on DACs. Link here (PDF)

At the heart of every digital audio playback system lies the single-most critical component for high-fidelity audio: the digital-to-analog converter (DAC). These converters handle the delicate task of translating the 16-bit binary words encoded on the disc or tape into corresponding analog signals worthy of amplification and, ultimately, of the human ear.

App note: Influence of control loop by an output filter

Posted on Sunday, June 11th, 2017 in app notes by DP | 1 Comment

an_wurth_elektronik_ANP006

Application note from Würth Elektronik about the effect of filters that are added to the output of switching regulators. Link here

The output voltage of switching regulators has a voltage ripple that can disturb with electrical power supplied circuits and lead to electromagnetic disturbances. Thus output filters are often used for noise suppression, which may under certain circumstances have an influence on the control loop. To prevent output power losses it may be necessary to compensate the control loop.

No matter what switching regulator topology is used, as a result of the parasitic series resistor ESR and the parasitic inductance ESL of the output capacitor, the output current causes an undesired residual ripple. Depending on the capacitor type selected, a relatively large residual ripple is created, which has varying wave forms. A common electrolytic capacitor, for example, can have a ripple voltage of up to a few hundred millivolt, depending on the output power of the switching regulator. If a ceramic capacitor is chosen, the ripple voltage may only be a few tenth of a Volt.

Free PCB coupon via Facebook to 2 random commenters

Posted on Friday, June 9th, 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…)

Adjustable gain LNA

Posted on Friday, June 9th, 2017 in DIY by DP | No Comments

pics-final-600

Mare published a new build:

Low noise amplifiers are very useful. I built one with single BFG425W transistor with adjustable bias current.

Project info at Mare & Gal Electronics homepage.

Using Python to store data from many BLE devices

Posted on Thursday, June 8th, 2017 in ARM, techniques by DP | No Comments

raspberry-pi-with-python-controlling-a-set-of-hexiwear-ble-devices

Erich Styger has written an article describing a technique he used to collect and store data from several BLE devices with Raspberry Pi and Python scripting:

BLE (Bluetooth Low Energy) sensor devices like the Hexiwear are great, but they cannot store a large amount of data. For a research project I have to collect data from many BLE devices for later processing. What I’m using is a Python script running on the Raspberry Pi which collects the data and stores it on a file

More details at mcuoneclipse.com.

#FreePCB via Twitter to 2 random RTs

Posted on Tuesday, June 6th, 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.

SmallyMouse2 – Universal USB to quadrature mouse adapter

Posted on Tuesday, June 6th, 2017 in AVR, USB by DP | No Comments

SmallyMouse2-complete-PCB-600

Designed and built by Simon Inns, a universal USB to quadrature mouse adapter project – SmallyMouse2:

SmallyMouse2 is a universal USB to quadrature mouse adapter for many 8-bit and 16-bit retro computers and allows the use of modern USB mice on machines such as the Acorn BBC Micro, Acorn Master, Acorn Archimedes, Commodore Amiga, Atari ST and many more.  Unlike most existing mouse adapters, SmallyMouse2 implements a fully USB compatible interface (most current adaptors are PS/2 based) this allows the use of any modern mouse including those that use wireless communications.

More details at waitingforfriday.com.

Project files are available at GitHub.

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