uVolume T-32 USB volume & media control update

in AVR, infrared by DP | 1 comment


Another update on µVolume USB volume control project by Rupert Hirst of  RunAwayBrainz, we covered it previously:

µVolume T-32 USB Volume Control update, featuring infra red media control

-Arduino Compatible (Atmel Atmega32u4)
-Manual volume adjustment using the rotary encoder
-(IR) Infra red remote control of volume and multimedia controls
-Apple remote or user defined
-Visual and audible Feedback
-RGB Lighting Customization’s


MakeyMakey from Dirty PCBs

in project logs by DP | 0 comments


TomKeddie writes:

MaKeyMaKey was a very successful Kickstarter from some smart guys at MIT. It uses capacitive touch to stimulate USB HID devices using a Arduino Leonardo compatible programming environment.

We ran a workshop at VHS in Vancouver Canada in July 2014 building these using PCBs from Dirty PCBs. The design is open hardware, the Eagle files, bootloader and sketches can all be found on github.
I’ve contributed a layout photo, parts list and basic instructions at github.

Via the project log forum.

At HOPE, EFF releases code for Open Wireless router

in News, security by the machinegeek | 0 comments

At last weekend’s HOPE Conference in New York City, the EFF released the code for their experimental hacker alpha wireless router software specifically designed to support secure, shareable Open Wireless networks.

We are offering this hacker alpha release to engage enthusiastic technical users who would like to help us test, develop, improve, and harden the Open Wireless Router. Currently the software runs on one specific model of hardware (the Netgear WNDR3800) and is based on the CeroWRT project. If you have a WNDR3800 router, you can get the developer preview image here and learn how to flash it here. If you’d like to hack on the code base, you can find code and instructions on building it at Github.

Currently the software runs on one specific model of hardware (the Netgear WNDR3800) and is based on the CeroWRT project.

For more info visit the EFF open wireless router page.

Random spottings on factory tour

in #liveupdates by Ian | 0 comments


Joined a friend on a factory audit today totally unrelated to anything electronic. Spotted a few cool thongs though. This is a metal polishing station with a red bull can full of polish.


Down the hall is an unrelated factory making plastic tubing for bag machines. ABS plastic pellets go in the hopper and tube spits out. The single worker running the while factory occasionally measures the output with a ruler.


The tube goes into a bag making machine like this one we spotted at the south China market with Zach Hoeken last week.


Speaking of south China market, that place is strange. Here’s one of a hundred fur shops. Never seen anything like it. No red paint anywhere in sight. More on south China market shortly. Maybe write it up on way back to office from this tour.

Taxi death on way to Shenzhen factory visit

in #liveupdates by Ian | 6 comments


Took a taxi about an hour to the manufacturing area of Shenzhen, Bao’on. When we got in it seemed like there was something wrong with the car or driver, 3rd and 4th gears seemed nonexistent.

Initially I though maybe we should swap cabs, its a long trip after all. But that seemed just too paranoid.

Paranoia in this case was founded. In the middle of nowhere, on a toll road, the car starts to crap out. The driver, unphased, ignored our suggestion to pull over and drove the thing until it died in the middle of the high speed road.

Being a toll road there aren’t any taxis trolling for pickups, and Uber was nowhere to be found. Standing on the shoulder of a Chinese road is terrifying as it became a temporary lane, compensating for the one occupied by the broken taxi. Eventually with enough pleading another taxi came to pick us up.

To his credit the driver added water and oil and got the car going. Didn’t sound like it would make it far though.


In conclusion I leave you with a photo of a Tsing Tao beer adversisment on the toll booth we just past.

Posted in #liveupdates | 6 Comments

ASTROGUN R-Pi based asteroid game

in code, R-Pi by the machinegeek | 0 comments

Avishay has developed the ASTROGUN, a Raspberry Pi based asteroid shooting gun and video display system. He originally designed the project along with Maayan Dreamer for the Jerusalem Mini Maker Faire, held last June.

The game is pretty simple – the player stands and has to shoot Asteroids that are coming towards him from any direction, before they hit him. A RADAR-like view helps the player locate the Asteroids around him. The most interesting thing is the display system. We build a HUD – heads up display – which is a display that shows an image overlaid on the background.

More information and source code link is available on Avishay’s blog page.

Via the contact form.

Free PCB Sunday: Pick your PCB

in Free PCBs by DP | 36 comments


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:

Continue reading →

Posted in Free PCBs | Tagged | 36 Comments

App note: Design of a low cost, 45W flasher with short circuit protection using LM2902 (Quad Op-Amp) and CSD18534

in app notes by DP | 0 comments


App note (PDF) on automobile flashers from Texas Instruments

This Application note presents the design of a low cost, flasher circuit with short circuit protection. The design incorporates the entire recommended design feature set for two wheeler flashers and includes low/high voltage operation, half load frequency doubling, and short circuit protection.

App note: Use of MLCC capacitors

in app notes by DP | 0 comments


App note(PDF) on using Multi-layer ceramic chip(MLCC) capacitors from Altera.

Multi-layer ceramic chip (MLCC) capacitors are used quite often in dc-dc converter input and output filters instead of tantalum or aluminum electrolytics. MLCC’s have low ESR, low ESL, and low cost. They also have no major reliability problems associated with them. All these properties make them suitable for power management applications. There are still, however, some issues to consider when using these capacitors in dc-dc converter circuits. Some ceramic capacitors can lose a lot of their value under certain conditions. This lost capacitance can degrade the transient response of a dc-dc converter, or it can even make the control loop of the converter unstable.

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App note: Using the AVR’s High-speed PWM

in app notes by DP | 0 comments


Atmel’s app note on using the AVR’s High-speed PWM (PDF!):

This application note is an introduction to the use of the high-speed Pulse Width Modulator (PWM) available in some AVR microcontrollers. The assembly code example provided shows how to use the fast PWM in the ATtiny26. The ATtiny15 also features a high-speed PWM timer.
The fast PWM is used to generate a pulse train with varying duty-cycle on the OC1A output pin (PB1). An analog filter can be used to shape the digital PWM output to obtain an analog signal such as a sine wave.
The advantage of high-speed PWM is the increased bandwidth of the analog output signal and that the high frequency allows for smaller and less expensive filter components used to shape the signal.

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App note: High voltage, low noise, DC/DC converters

in app notes by DP | 0 comments


An app note from Linear Technology: High voltage, low noise, DC/DC converters (PDF!)

Photomultipliers (PMT), avalanche photodiodes (APD), ultrasonic transducers, capacitance microphones, radiation detectors and similar devices require high voltage, low current bias.  Additionally, the high voltage must be
pristinely free of noise; well under a millivolt is a common
requirement with a few hundred microvolts sometimes
necessary. Normally, switching regulator confi gurations
cannot achieve this performance level without employing
special techniques. One aid to achieving low noise is that
load currents rarely exceed 5mA. This freedom permits
output fi ltering methods that are usually impractical

SWD programmer for PSoc4 based devices

in programmers by DP | 0 comments


ghent360 writes:

For those of you who want to program a PSOC4 based device I have a firmware for FX2LP device + PC software to perform the operation. It has the same hardware interface as the device here: PD0-SWDIO;PD2-SWDCL;PB2-XRES. You can also use any “cheap as chips” board from ebay or amazon.
Here are the sources for the project

Via the forum.

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Logic Pirate back in stock

in News by DP | 0 comments

Logic Pirate

Logic Pirate is back in stock at Seeed Studio.  It is an inexpensive, yet capable open source logic analyzer. It can sample 8 channels at 20 million samples per second, and may be overclocked for even faster acquisitions. It’s designed to support the open source SUMP logic analyzer protocol with software available for most operating systems.

You can get a Logic Pirate for $30.

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Free PCB coupon via Facebook to 2 random commenters

in Free PCBs by DP | 11 comments


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. More PCBs via Twitter on Tuesday and the blog every Sunday.

Don’t forget there’s free PCBs three times every week:

Continue reading →

Posted in Free PCBs | Tagged | 11 Comments

Week in (p)review July 25, 2014

in week in review by DP | 0 comments


Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon.

Coming up:

  • Free PCBs via Facebook on Friday
  • App notes on the weekend
  • Free PCB Sunday
  • Free PCBs via Twitter on Tuesday
  • Weekly roundup and preview every Friday

An open letter to NXP Semiconductors about LPC1114FN28

in ARM by DP | 3 comments


ytsuboi  wrote an open letter to CEO of NXP, and get replied:

I sent this e-mail to the CEO of NXP Semiconductors. (23 July 2014, 4:36am JST)

To: NXP Semiconductors N.V‎
Richard L. Clemmer, Executive Director, President and CEO
Dear Mr. Clemmer,

About a week ago, I found an unbelievable information about LPC1114FN28 on Digikey and Mouser. That was “LPC1114FN28 has been marked as obsolete and is being discontinued.” I confirmed LPC1114FN28 is in your 2014 Mid‐Year Product Discontinuation list. (On the top of page 11) As well as I know, LPC1114FN28 is in the list of your longevity, 10-year promise list. By that list, longevity date of LPC1114FN28 is 2022-08-08. Here is the archive of your web page.

For this year, I spent a time to port mbed SDK for some of your products. As you may know, NXP is introducing mbed as one of your “Tools Ecosystem”. As well as I know, 1,000+ people are using LPC1114FN28 on online compiler of mbed. We purchased LPC1114FN28 through NXP’s official distributor, but I’ve never got any accurate information from those channels.

So, I have a few questions.
- Which information is correct? Will you discontinue that at the end of the year or not?
- Why NXP is showing inconsistent information? I thought discontinuance is very important decide for semiconductors.

If you will discontinue that,
- What is your “promise”? How can we believe you will keep your words from today?
- I know 1k something is not large number for semiconductors, but why are you ignoring us?

Hope to hear your sincere attitude.
Yoshihiro TSUBOI

# This is an open letter, I already published this e-mail on my blog. And I will publish your reply on my blog. http://www.ytsuboi.org/wp/archives/2281

 I got a reply at 24 July 2014 15:05pm, JST. Thank you, NXP. I really felt your sincerity.

Continue reading →

Posted in ARM | Tagged , , | 3 Comments

Sound activated switch

in DIY, sensors by DP | 0 comments


A sound activated switch project by Rajkumar Sharma of Electronics Lab:

Clap switch/Sound-activated switch designed around op-amp, flip-flop and popular 555 IC. Switch avoids false triggering by using 2-clap sound. Clapping sound is received by a microphone, the microphone changes the sound wave to electrical wave which is further amplified by op-amp.
555 timer IC acts as mono-stable multi-vibrator then flip-flop changes the state of output relay on every two-clap sound. This can be used to turn ON/OFF lights and fans. Circuit activates upon two-clap sound and stays activated until another sound triggers the circuit.

Posted in DIY, sensors | Tagged , | Leave a comment

Reverse engineering a wireless soil moisture sensor

Ray Wang at Rayshobby has been working on reverse engineering a wireless soil moisture sensor. He writes, “At the Maker Faire this year I got lots of questions about soil moisture, which I knew little about. Recently I started learning about how to build my own soil sensor, and came across this cheap 433MHz wirelss soil sensor available from Amazon. I’ve experimented with some similar wireless sensors (temperature, humidity, rain etc.), so it didn’t take me long to figure out the signal encoding pattern of this one. I wrote an Arduino program (also adapted to R-Pi) to listen to the sensor and print out the soil moisture level to the serial monitor. This provides a convenient and low-cost solution to integrate soil sensors to my home automation projects.”

Via the contact form.

New microchip promises to streamline and simplify diabetes diagnoses

in Chips by DP | 0 comments


Dr. Brian Feldman and his team at Stanford University have developed a new microchip. It promises to streamline and simplify diabetes diagnoses. Ben Coxworth of Gizmag writes:

For people who don’t already know, here’s the difference between type 1 and type 2 diabetes: the body produces little or no insulin in the case of type 1, and isn’t able to utilize the insulin that it does produce in type 2. It’s a significant difference, so it’s important that patients are diagnosed correctly. Thanks to a new microchip developed by a team at Stanford University led by Dr. Brian Feldman, doing so could soon be quicker, cheaper and easier than ever before.

Via Electronics Lab.

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