Hacker Camp Shenzhen Day 1: Huaqiangbei market tour

in Hacker Camp Shenzhen, Shenzhen by DP | 1 comment

By ian


Huaqiangbei is probably the largest electronics component market in the world. It’s why we’re here for Hacker Camp Shenzhen, it’s why most people are visiting. On day one we broke into four groups and toured the market. Everyone was introduced to guides’ favorite distributors, and we bought a few goodies along the way. Check the day one tour below.


IMG_7484-W600After discussions and before the tour we hit the local Cantonese place for WAY too much food. Joe @ Arcbotics and Ian plan the tour route in the lower left.


The tour wound through the used cell phone markets and past the cell phone components market. Along the way we stopped at the ‘Hokkien Brothers’ shop for a few pre-arranged gifts: screw drivers and solvent dispenser bottles. This is where we buy all our tools, and many people on the tour found their way back here later for tools.


A group checks out the Qinsi pick and place machine on ‘fourth floor’ tool building. It’s very similar to the TM220.


You’ll buy a lot in Huaqiangbei, and it probably won’t fit in your luggage. Suzie shipper provides inexpensive air freight to most of the world, and she’s a must-meet stop on the tour.


Our final stop on the tour is the ‘dodgy cell phone market’. Here you find all sorts of oddities. From $10 credit card sized phones with OLED displays, to 3G replicas of giant 1980′s phones, to this surprise on we encountered accidently on the very last stand of the tour.


This little guy is clearly a MiPhoneK with a cute Android Robot logo.


Though a bit of alcohol reveals the Apple logo and something resembling an iPhone color running Android 4.x. For $40 it’s worth it for the show alone, but there’s some surprises inside we’ll reveal in a future tear down.


After the tour everyone headed back to their favorite stands to forage for treasure. We all exchanged part pr0n via WeChat, a message program that’s super popular in Asia.

Via Hacker Camp Shenzhen mini-site: Hacker Camp Shenzhen Day 1: Huaqiangbei market tour

Dirty Circuits PCB routing for open hardware designs

in PCBs, skills by DP | 0 comments


At Dangerous Prototypes we have a team of amazing PCB designers. We crank out a lot of boards publicly and privately, but even we can’t keep these hungry routing addicts busy all the time. Now we’re lending our routing skills to you for your open hardware project through a new site: Dirty Circuits.

If you have an open hardware project and would like help routing the PCB, we’re here to help:

  • Turn a completed schematic in KiCAD or Eagle into a pretty PCB
  • Turn a stack of Arduino shields and a circuit drawings into a schematic and integrated PCB
  • Turn a hand drawing into a great looking KiCAD or Eagle schematic
  • Build that stack of component footprints you don’t want to do yourself


You can take a look at our previous designs at Dangerous Prototypes. The same routers will work on your PCBs. All designs are hand routed, never autorouted.

Here’s some comments from our private beta testers. A quick fix of inconsistencies that caused a major setback:

..I don’t want it to get weird or anything, but I might kiss you next time I see you. Just sayin’. Huge thanks. Gargantuan colossal thanks. For real, I was sweating bullets about how I’d find time to fix my mess up.

A full board routing:

This looks fantastic. It’s as good as I could have done in Altium, but in Eagle, so I can share the damn design files and have them be useful to people. He even caught that I forgot to add test points for the battery charger and soft power. Hot damn. Hot diggety damn.

We only route the PCB. Any design flaws in the circuit are beyond our control, but we make every effort to route perfect PCBs. In cases where we mess up really bad, we’ll probably fix the design and buy you a new set of PCBs.

What we don’t do…

We are able to route digital designs for open hardware projects. There are many things we don’t want to do:

  • Engineering or design. We just route PCBs, you have to prove the circuit
  • RF or complicated analogue design (impedance balancing, etc)
  • More than 2 layers/10x8CM in Eagle because so few can edit the files (2+ is fine in KiCAD)
  • Closed hardware projects

Keep it Dirty

For more please head over to Dirty Circuits to read the FAQ and submit your boards for routing.

Hacker Camp Shenzhen Day 1: Surviving Shenzhen

in Hacker Camp Shenzhen, Shenzhen by DP | 0 comments

By ian


Each morning of Hacker Camp Shenzhen started with a 2 hour discussion of various Shenzhen and electronics stuff. The first day Ian @ Dangerous Prototypes gave an overview of Shenzhen, food options, and essential life skills for getting around. Jin @ FlyLin gave a crash course overview of Chinese that introduced basics like numbers, hand signals, and how to get “this one”.

Day one presentations are available for download here. Videos will be posted shortly. Check below for pictures of the goodie bags and highlights from day 1 discussions.


Everybody gets a goodie bag! These swag sacs were fashioned from antistatic bags and rainbow ribbon cables with 2

DIY 100W LED flashlight

in hacks, LEDs by DP | 2 comments

In this video Julian Ilett demonstrates his DIY 100W LED flashlight:

I discovered that due to a lucky co-incidence of voltage and internal resistance, a 100W LED can be connected directly across the terminals of two 18V Nickel Cadmium power tool batteries. And that means you can build a 100 Watt (7,500 Lumens) flashlight for less than $10 (not including batteries).
Note: Don’t try this with other battery types – you’ll almost certainly fry the LED!

Via Hacked Gadgets. Continue reading →

Posted in hacks, LEDs | Tagged , | 2 Comments

Laserworld CS-500RGY laser projector teardown

in Teardowns by DP | 0 comments


Jaanus did a teardown of a Laserworld CS-500RGY laser projector:

I got my hands on a Laserworld CS-500RGY laser projector. This is the smallest 500 mW one. It is a device that has three laser sources (red, red and green) and mirrors for moving laser pointer. It can be controlled by sound, DMX512 or ILDA interface. So, lets tear it down.

Review: building publicLab’s DIY spectroscopy kit

Rohit writes,

I made a Opensource Spectroscope using the publiclab’s kit. I was surprised to see the kind of accuracy you can get from these easy to make Spectroscopes. I probed around a lot of light sources like LEDs, Sunlight, Tubelights and Bulbs. With LEDs I was able to estimate the forward drop in a RGB Strip for the different colors very accurately. The spectrographs of Sunlight confirmed the presence of IR and UV. The bulb’s spectrograph showed that it emits large amount of IR.The Tubelights ones showed that it is designed to render light very close to sunlight.

Quite Amazing science from a very easy to make scope.

You can read Rohit’s description of the build and review on his Indian Tinker blog and also at Instructables.

#FreePCB via Twitter to 2 random RTs

in Free PCBs by DP | 0 comments


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.

miniLOG – Precision standalone voltage logger

in Arduino, project logs by DP | 1 comment


Jakub Felcenloben over at Electronics Lab has written up documentation on his latest project called miniLOG, a basic data logger:

miniLOG is a precise standalone voltage logger that save the data on a SD card. It has 4 basic analog channels:

  • one has 12bit resolution for voltage measurements,
  • two channels have 10bit resolution for voltage measurements and
  • one channel has 10 bit resolution for current measurements.

Input voltage range is 0-25V and current range is 0-500mA. The data are written on a simple .txt file on SD card and can be further proccessed using spreadsheet software.

Hacker Camp Shenzhen Day 0: Dongmen and Copy Mall Tour

in Hacker Camp Shenzhen, Shenzhen by DP | 1 comment

By ian


Before the workshop started we planned to take a few early arrivals to Dongmen and the Copy Mall. Instead, almost the entire group came.

We hit Dongmen, China’s largest street market and the oldest market in Shenzhen (Laojie metro stop exit E). Highlights included the pirate software vendors, glasses world (eyeglass and contact wholesale), and the outdoor sign making street.

No trip to Shenzhen is complete without a visit to Louhu Commercial City (the Copy Mall, Louhu metro stop exit A). The Copy Mall is full of top quality knock-off of designer clothing brands. Forget that though, on the top floor there’s tons of fabric and Jery, our favorite tailor

The sign making street. All those blinking LED signs come from somewhere, this is but one street of sign makers. We cruised the street and saw people using hot-glue to stick LEDs into metal signs. We stopped at the fanciest store and picked up a detailed catalog that lists design guidelines like minimum and maximums for various sign materials. Several people had custom signs made for workshops and hackerspaces.

Pictures of the adventure below.

Continue reading →

Hacker Camp Shenzhen Day -1: Pre-game dinner at Japanese Secret Location

in Hacker Camp Shenzhen, Shenzhen by DP | 0 comments

By ian

Anyone arriving early was invited to “Japanese Secret Location” in Louhu, the oldest part of Shenzhen, for an all you can eat, all you can drink, Japanese dinner. This is one of our favorite dining spots and we wanted to share it with everyone.

Continue reading →

NEW PROTOTYPE: Logic Pirate 8 channel, 256K sample, 60MSPS logic analyzer

in Logic Pirate, Prototypes by DP | 9 comments

Logic Pirate

The Logic Pirate is an inexpensive yet capable open source logic analyzer. For just 30 bucks it can sample 8 channels, 256K samples per channel, at a blazing (overclocked!) 60 MILLION samples per second! It’s designed to support the SUMP logic analyzer protocol on Jawi’s open source software that works on most platforms.

More than a year ago Ian joined the Amp Hour podcast and discussed his goal to make a highly useful, very accessible logic analyzer for around $30. A few weeks later forum regular m.gritsch contacted us about using his design as a successor to the Logic Shrimp v1.

This type of logic analyzer is drastically different than a FPGA-based device like the Logic Sniffer we designed with the Gadget Factory so many years ago. The Logic Sniffer uses programmable logic to create memory, triggers, clocks, tons of fancy stuff all inside one chip. Data is acquired and stored directly inside the FPGA.

The Logic Pirate (based on the Logic Shrimp, which was based on the closed-source Scanalogic) uses serial memory chips to store the samples. These chips have much more storage than a FPGA at a much lower cost, however they’re not as fast and lack the complex trigger logic found in a FPGA-based design. If you want max speed and complex triggers, an FPGA design like the Logic Sniffer is a MUCH better choice.

A sneaky feature exploited by the Logic Pirate is overclocking. The SRAM chips used are rated for 20MHz (20MSPS) maximum. However that rating is at temperature and voltage extremes. In practice, we find that sampling up to 60MHz (60MSPS) is reliable in practice! If you’re willing to push the limits, this is a dirt-cheap, big-samplin’ smoking little logic analyzer.

Continue below to read about the v1 initial design, or see the latest revisions on the documentation wiki.

Here are some of its features:

  • 8 channels
  • 256 kSamples recording size
  • 60 MHz (overclocked) sampling rate (20 MHz and lower non-overclocked)
  • No compromise when combining the values above
  • Simple configurable edge detection triggers on all inputs (simple OR trigger)
  • Configurable ratio of samples from before and after the trigger (rolling sample buffer)
  • 5 V tolerant inputs (LOW-level voltage < 0.8 V, HIGH-level voltage > 2.0 V)
  • About 500 kB/s transfer speed to the PC (256 kSamples take about 0.5 seconds)
  • Data capturing can be stopped from the host software anytime
  • Cross platform host software for Windows, OS X, and Linux
  • DIY-friendly 0603 parts and SOIC packages used on a 2-layer board
  • On board 3.3 V regulator can supply up to 400 mA to an external circuit
  • Tiny 3cm x 3cm PCB
  • Firmware updates via built-in USB bootloader
  • Probe cables and acrylic case available from Seeed Studio
  • Open source PCB (EAGLE) and firmware files

Some features of the host software:

  • Precise measurement by using up to ten free placeable cursors
  • Automatic period, frequency, and duty cycle measurement
  • Displaying channel groups as HEX values and/or as an analog signal
  • Analyzers for a large number of protocols: 1-Wire, I2C, JTAG, SPI, UART, etc.

Available now at Seeed Studio for $30. Continue reading →

Nixie HV switching PSU

in power supply by DP | 2 comments

MAX 1771 V4 populated top 1

From the comments on our earlier HV Nixie DC-DC switching power supply post, here’s a Nixie HV switching PSU by Nick De Smith:

It is probably beyond the scope of this simple document to describe the operation of switch-mode power supplies (SMPSs) – suffice to say the technique relies on the voltage pulse you get from rapidly collapsing the magnetic field in an inductor. This is done many thousands of times a second and the output pulses are collected and smoothed. Whilst this sounds simple, in practice it is complex to do well – there are a number of key design decisions that have to be made, and board layout is critical – SMPSs will not work well when built on Vero/StripBoard or prototyping plug-in boards – in fact, they may not work at all!
So, if SMPSs are tricky to work with, why use them? Simple – when they work they are brilliant! They are very small, cheap, completely solid-state, run cool and can be 90% or more efficient. This last point, efficiency, can be very important. SMPSs can lower a voltage (a “buck” converter) or increase the input voltage (a “boost” converter).

Via the comments. Thanks Xevel!

Posted in power supply | Tagged , , | 2 Comments

Re:Load Pro – A DC active load

in open source by DP | 0 comments


Here’s an interesting open source project on Kickstarter the Re:Load Pro by Nick Johnson of Arachnid Labs:

Today I’m finally launching the Re:load Pro on kickstarter. The Re:load Pro takes all the advantages of the original Re:load, and improves upon them with a robust benchtop case, a good quality display and UI, an isolated USB interface, and an integrated processor – the PSoC 4 from Cypress – that together make it an extremely sophisticated and versatile piece of equipment.

Via the forum.

Power bar, a small breadboard power supply

in project logs by DP | 0 comments


NsN has been working on a power bar, a small breadboard power supply:

The power bar is a small breadboard friendly power supply with three independent voltage regulators and built-in current monitoring.
The target applications are small, mostly digital projects, which don’t need a large 0-30V, 6A benchtop power supply, but at the same time want something more adjustable than the simple 5V USB voltage.

Via the forum.

Free PCB Sunday: Pick your PCB

in Free PCBs by DP | 57 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 | 57 Comments

App note: STM32™ in-application programming over the I²C bus

in app notes by DP | 0 comments


Programming the STM32F10x via I2C with this app note from STMicroelectronics

A key requirement for most Flash-memory-based systems is the ability to update firmware once the system is installed in the end product. This is referred to as in-application programming (IAP).

This application note describes how to perform in-application programming using the STM32F10x’s I2C peripheral. An USB-I2C bridge is required to send IAP commands to the target STM32F10x. The STM32F10x behaves as an I2C memory that can be programmed, erased and read via the I2C/ interface.

App note: STM32F10x in-application programming using the USART

in app notes by DP | 0 comments


Programming the STM32F10x via USART with this app note from STMicroelectronics

The STM32F10x microcontroller can run user-specific firmware to perform in-application programming (IAP) of the microcontroller-embedded Flash memory.

IAP driver must be program first to the Flash memory base address via JTAG/SWD interface using the development toolchain of your choice or the factory-embedded boot loader in the System memory area.

Then IAP driver can do:

-Download the binary file from PC via USART to the STM32F10x’s internal Flash Memory

-Upload the STM32F10x’s internal flash memory content (starting from the defined user application address) into a binary file.

-Execute the user program.

How to make your own custom GNU Radio blocks – the C++ way

If you’re a GNU Radio user you know that most of the functions you need are contained the stock group of GNU Radio blocks. However, there are times when you may want to code up a custom block to perform a unique function not found on the stock blocks. Jean-Benoit Larouche has posted the first of a multi-part tutorial at Nutaq’s blog explaining the process of making custom GNU Radio blocks. “Our custom block creation journey starts with the out-of-tree modules tutorial from on the GNU Radio website. This tutorial is a very good starting place for anyone who wants to learn the basics, under either C++ or Python. This post is intended to fast-track the creation of an out-of-tree module in C++.”

Part 2 and Part 3 are also available.

DIY external serial monitor

in Arduino, DIY by DP | 7 comments


ARPix  wrote this Instructable detailing the build of his DIY external serial monitor:

Sometimes I needed an external serial monitor like the Serial Monitor in the Arduino Editor, to see what is going on. So I made one. The first picture shows an example how could be it designed.

For the ESM I used an Atmel Atmega328 (based on the Arduino-Board) because it have an internal SRAM with 2KBytes. It’s necessary for the big data processing.
So you need more than 1KByte SRAM.
With the menu in the ESM you can do…
… setting the baud rate
… start and pause the reading

Breadboard programming cable for ATtiny85, ATtiny88, ATmega328, ATtiny2313, and other AVR MCUs

in how-to by DP | 0 comments


Here’s a breadboard programming cable for ATtiny85, ATtiny88, ATmega328, ATtiny2313, and other AVR MCUs by Nerd Ralph

For programming AVR MCUs, I use a USBasp. Initially, I would connect the USBasp header pins to header pins on the breadboard with individual jumper wires, then jumper the appropriate pins on the MCU. Then I noticed a repeating pattern in the pinout of many AVRs. Here’s an example.
Notice the pattern? MOSI, MISO, SCK, & VCC are all in the same order. Then I found this page with instructions on building a programming cable for an Arduino mini. I decided to build a simpler programming cable that would work on a number of AVR MCUs and Pro Minis with a minimum of jumper wires.

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