Hacker Camp Shenzhen vol 4: 182 degrees open for registration!

140405-IMG_20140405_162505-W600 Hacker Camp Shenzhen volume 4: “182 degrees” is on! Join us from Thursday April 1 to Saturday April 3, 2015 for fun, food and 3 solid days of electronics tours in Shenzhen China and beyond.

Tickets are available now. Come to the world’s electronics capital and experience Shenzhen like a local hacker. Tour the famous Huaqiangbei electronics markets with people who live in the neighborhood, figure out what to eat and how to get around.

This camp we’re adding an oft requested factory tour! Take our own party bus to a few factories around Shenzhen. Exact factory visits will be determined by you! We’ll take requests and try to include something for everyone.

Saturday we’ll explore electronics and tools markets most foreigners could never find: Yihua and the massive Shajing.


  • Optional: Tuesday March 31 – Dinner at Szechuan place
  • Optional: Wednesday April 1 – Tour of Dongmen market & sign street, copy mall, early arrival dinner at Japanese Secret Location
  • Thursday April 2 – How to survive Shenzhen, Huaqianbei tour, hot pot dinner
  • Friday April 3 – Factory tours, BBQ dinner
  • Saturday April 4 – Tour of Yihua and Depu markets, Hacker shaokao

That’s just an overview. See the full Hacker Camp Shenzhen schedule here. You can expect nightly dinners and parties all week. Be sure to give yourself a few days to explore the market on your own after the camp!


Tickets for the camp cover bus rental, materials, meeting room, a translator, a set of PCBs, and 3 bottles of Tsing Tao (Ching Dao) per dinner. There’s only 20 tickets available and we expect they will sell out fast. Or maybe it’ll be a small intimate group. Who knows! We’re excited to see you there!

  • Student/Starving Artist ticket – $250
  • Normal ticket – $300
  • Supporter ticket – $400 (your name on the site and schedule of every future camp)

We also include allowance for Paypal fees, wire transfer fees, and currency conversion. Hacker Camp Shenzhen is a “no profit” event, meaning we’re lucky to break even.

Where to stay, visas, how to get there

City Inn is the recommended hotel, but be prepared for really bad internet and no WIFI. Check out the Hacker Camp mini-site and our Shenzhen survival guide. Be sure to get WeChat and join the Shenzhen Hacker group chat after you buy a ticket!

SIM card provided

We’re traveling to places an hour or so north of Shenzhen, there are no taxis and nobody speaks English. Everyone must have a working SIM card with data, and this camp we’ll provide them!

Can’t make this one?

Hacker Camp Shenzhen volume 5: “Pun TBD” will be in June 2015, just prior to Shenzhen Maker Faire.

Hacker Camp Shenzhen mailing list!

Don’t miss out, signup to be notified about upcoming hacker camps in Shenzhen!

USB interfacing for AVR microcontrollers

in AVR, USB by DP | 0 comments


Ralph Doncaster  writes:

Since the release of V-USB, dozens of projects have been made that allow an AVR to communicate over USB. USB data signals are supposed to be in the range of 2.8 to 3.6V, so there are two recommended ways to have an AVR output the correct voltage. One is to supply the AVR with 3.3V power, and the other is to use 5V power but clip the USB data signal using zener diodes. Most implementations of V-USB, like USBasp, use the zener diodes. I’ll explain why using a 3.3V supply should be the preferred method.

Free PCB Sunday: Pick your PCB

in Free PCBs by DP | 84 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:

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App note: EMI and ESD filtering of audio interconnects

in app notes by DP | 1 comment


App note(PDF) on NUF2441FC EMI and ESD filter chip from ON Semiconductor.

The continued ever-increasing integration of more functions into personal electronic devices such as cell phones has made electronics manufacturers demand more integrated functions to reduce part count and save board space. Cell phone manufacturers have also driven component manufacturers to produce more efficient parts to increase the battery life on cell phones. Quite often though this is done at the cost of added sensitivity to ESD. Concurrently, as data rates and clock speeds increase the need to filter Electromagnetic Interference (EMI) also needs to be resolved. The ON Semiconductor NUF2441FC was designed to provide both ESD protection and EMI filtering for headset and speaker phone lines in cell phones with low line losses. This dual function component reduces part count and significant board space in a Flip-Chip package offer excellent performance at a low cost.

App note: Analog switches solve many problems within a cell phone

in app notes by DP | 0 comments


Applications(PDF) of analog switches inside a cell phone by ON Semiconductor.

Analog switches have been available since the 60’s as a component for systems designers. With the advent of ASICs and ASSPs, many designers have not experienced the real value of these devices. Today’s designers may be familiar with the venerable MC14066, a workhorse that has been around for 30 years or more. The device consists of 4 independent switches that provide bilateral capabilities when “ON” and nearly infinite impedance when “OFF”.

Enter the single gate solution: On Semiconductor now offers a low voltage, single version of the 4066 in a one gate package. The MC74VHC1G66DFT2 is a single switch (SPST) occupying less than 4.5 mm 2 package, specified from 2.0-5.5 V and offers < 25 ohms resistance when turned “ON” and almost infinite impedance when turned off. Interestingly, the device can pass/stop either a digital or analog signal. Digital signals get passed with <1.0 ns delay, and very nearly no change in the signal. Analog signals get passed with less than 0.1% distortion and the device has a –3.0 dB point of >100 MHz. Several more devices were added to the portfolio including SPST, SPDT, dual SPST, DPDT, 2:1 Mux, dual DPDT functions. These are all available in tiny packages from 2.1 x 2.0 mm to 3.0 x 3.0 mm.

App note: Li-Ion/Polymer Shunt battery charger system with low battery disconnect

in app notes by DP | 2 comments


Li-Ion/Polymer Shunt battery charger system with low battery disconnect (PDF!) app note from Linear Technology:

The LTC®4071 allows simple charging of Li-Ion/Polymer batteries from very low current, intermittent or continuous charging sources. A near zero current low battery latching disconnect function protects even the lowest capacity batteries from deep discharge and potentially irreparable damage. The 550nA to 50mA operating current makes charging possible from previously unusable sources. With its low operating current the LTC4071 is well suited to charge low capacity Li Ion or thin film batteries in energy harvesting applications. The unique architecture of the LTC4071 allows for an extremely simple battery charger solution, requiring just one external resistor.

App note: 1-Wire communication with PIC microcontroller

in app notes by DP | 0 comments


An application note (PDF!) from Microchip on 1-Wire communication with PIC microcontroller:

This application note introduces the user to the 1-Wire® communication protocol and describes how a 1-Wire device can be interfaced to the PIC® microcontrollers.
1-Wire protocol is a registered trade mark of Maxim/Dallas Semiconductor.
A software stack for the basic, standard speed, 1-Wire master communication is provided with this application note along with an example application

Flir Lepton thermal imaging sensor + gameduino 2

in hacks, sensors by DP | 0 comments


Andrew Rossignol of The Resistor Network writes:

I have successfully implemented a driver for the Lepton module and displayed frames on an LCD. This is all running on an STM32F4 processor on a Nucleo board. Attached to it is a Gameduino 2 which incorporates the FT800 graphics processor. I have implemented my own colorization and min/max scaling before uploading the frames to the GPU.
I have used some simple jumper wires to interface with this camera. This setup is running at 21MHz with no issues. I am using a breakout board provided by Pure Engineering. You can pick up one from Tindie if you are interested. The Lepton module can be ripped out the Flir One iPhone accessory for now.
I wrote my own driver for the Lepton core and the FT800 graphics processor.

For more details visit Andrew’s website.

Free PCB coupon via Facebook to 2 random commenters

in Free PCBs by DP | 3 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.  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:

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Posted in Free PCBs | Tagged | 3 Comments

On Western Digital hard drives, PUIS and Rocket Raid controllers

in repair by DP | 0 comments


Peter Hofmann fixed his drives and documented the whole process on his blog:

After about a day of trial and error, I finally fixed my drives. To save anyone else the days worth of effort, I’ve documented my solution here:

Firstly you need to go and find a tool called HDAT2 from www.hdat2.com download it and create a boot disk for it.
Then a tool called MHDD is needed but you need to inject the bootable ISO with some script files from the above hddguru address. Problem is, this is quite difficult and requires a floppy drive, or a virtual floppy drive which turns out is quite difficult to use on a 64 bit machine. Virtualbox and 32bit windows XP to the rescue. After a fair bit of futzing around I finally ended up with a final ISO file that can be burned and booted – the hddguru post doesn’t say exactly where one of the bin files needs to go so I had to guess around a bit before getting it right. Get the bootable ISO from here dl.dropboxusercontent.com
If you want to make your own, then just remember that PUIS goies in the scripts dir and off.bin goes into the dir above that

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The Commodore 64 Flash Cart (C64FC) is done!

in AVR by DP | 5 comments

c64fcrc2done-big (1)

The Commodore 64 Flash Cart (C64FC) project by Stian Soreng:

A few days ago I had a breakthrough getting the device to identify as an USB HID device, and yesterday it all just “clicked.” The device works and transfers images without a hint of problems. Release candidate 2, with its minor hardware patches, is perfect
Since the cartridge identifies as a HID device, no drivers are required! The client software automatically detects it on the USB bus and communicates with it. File transfers are so smooth and fast you have to see it for yourselves

Check out the video after the break.

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Posted in AVR | Tagged , | 5 Comments

Single Cell Software frees Korg Volca Sample from iOS chains

in Android, software by the machinegeek | 0 comments

If you experiment with electronic music, you’ve probably heard of Korg’s latest addition to their Volca line known as the Volca Sample. The volca sample is a sample sequencer that lets you edit and sequence up to 100 sample sounds in real time. It lets you recreate the characteristics of the first generation of samplers, in which any sound including vocals, spoken words, ambient sound, or glitches becomes material for your creations. The catch was that initially and officially, the only way to get audio samples into the device was to use an iOS device to record the audio, then transfer it over a 3.5 mm stereo cable to the Volca Sample’s sync input port.

Then Korg released the code for their SDK and almost overnight Rej, developer of theCaustic 3 music creation software released an Android app along with versions for Windows and Mac! While the source code has not been released, the app is known as Caustic Editor for Volca Sample and is available for free from Rej Poirier. Visit his Single Cell Software for downloads and more details on this and his other projects.

Via LearnToMakeHipHop.

Power plug energy meter – Now wireless!

in Arduino, wireless by DP | 1 comment

2014-11-17 22.05.39

Kalle Löfgren writes:

Today’s post will cover how I managed to get an Arduino pro mini (3.3V) to sniff the energy meters SPI and transmit the data wirelessly with a nRF24L01+ to an Arduino Nano connected to a computer. The neat thing with this setup is that the Arduino pro mini and the nRF fits perfectly within the casing of the energy meter, and are both driven by the internal power that charges the rechargeable battery that you’ll find in the meter.

Blueprintf – a bluetooth serial monitor

in DIY, gadget by DP | 0 comments


Bob Alexander of Galactic Studios made this bluetooth serial monitor for embedded microcontroller projects, the Blueprintf:

One way of debugging microcontroller-based projects is to send messages out the UART serial port. Then, a UART-to-USB interface can feed the messages into your PC for display. But I wanted a small, portable device for viewing serial data without a PC, and I wanted it to use my cell phone or tablet for its display.
There are a few advantages to this. First, I don’t always have my PC nearby; maybe the project worked fine on my workbench, but doesn’t work “in the field” where I don’t have a PC handy. Second, the UART-to-USB interface sometimes hangs, especially if there are glitches from the system under test (SUT). Finally, sometimes I just don’t want to string the wires from the embedded system to my PC

Check out the video after the break.

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3D printing pen

in 3D fabrication, tutorials by DP | 0 comments


Jason Poel Smith posted a tutorial on 3D printing pens and how to use them, instructable here:

How Does it Work?
Like all 3D printing devices, a 3D printing pen works by heating a plastic filament to its melting point and forcing it through an extruder tip. This is very similar to how a hot glue gun works. The melted plastic is very soft and can be fused onto a surface or worked into any shape that you want. Once the melted plastic leaves the tip, it begins to quickly cool down. After a few seconds, the plastic hardens and holds whatever shape you have worked it into.

What Can You Do With a 3D pen?
These pens allow you to effectively draw with plastic. You can work the plastic into just about any shape and apply it to most surfaces. You can use it to add raised decorative designs to everyday objects. With practice, you can even make 3D drawings in empty space. These pens can also be used to modify and repair other 3D printed objects.

Check out the video after the break. Continue reading →

PCB printer

in PCBs, tools by DP | 10 comments


You can now print your own circuit boards.  Check out this cool Voltera, a circuit board rapid prototyping platform:

Circuit Board Printer
Print dual layer PCBs on FR4 with 10mil space/trace. Our 20mΩ/sq sheet resistance and conventional soldering makes prototyping a breeze

Solder Paste Dispenser
Forget stencils. Pop your board in and dispense solder paste onto printed OR traditionally fabbed boards

Reflow Capabilities
With a 550W heater watch your components reflow and skip the hassle of hand soldering altogether.

Via Make (video).

Check out the video after the break. Continue reading →

Posted in PCBs, tools | Tagged | 10 Comments