app note: Stepper Motor Driver for Smart Gauges

in app notes by DP | 0 comments


A smart gauges stepper motor driver app note from Cypress.

This application note shows how to use the PSoC® Programmable System-on-Chip to drive a low-power stepper motor for smart pointer gauges. This application note demonstrates how to perform micro stepping in the stepper motor using PSoC 1.In addition; this application demonstrates using a PC-based utility to control the pointer position in the stepper motor.

30c3 video: hacking RFID public access control systems

In this video from the 30th Chaos Communications Congress, Adrian Dabrowski lectured on RFID based access control systems which are becoming common in Europe. These systems debuted in 2006 and use RFID cards as a substitute for a previous mechanical key system to allow emergency service, delivery and other personnel unassisted access to the common areas of multi-occupant buildings.

We present a black-box analysis of an electronic contact-less system that has been steadily replacing a conventional mechanical key on multi-party houses in a big European city. So far, there are est. 10.000 installations of the electronic system. The mechanical key has been introduced about 40 years ago to allow mail delivery services to access multi-party houses but has since then aggregated many additional users, such as garbage collection, police, fire brigade and other emergency services. Over 92% of residential buildings in this city are equipped with such a solution.

App note: MAX31730 3-Channel remote temperature sensor

in app notes by DP | 0 comments


Here’s an application note from Maxim on triple remote temperature sensor:

The MAX31730 temperature sensor monitors its own temperature and the temperatures of three external diode-connected transistors. The operating supply voltage is from 3.0V to 3.6V. Resistance cancellation compensates for high series resistance in circuit-board traces and the external thermal diode, while beta compensation corrects for temperature-measurement errors due to low-beta sensing transistors.
All temperature channels have programmable temperature thresholds. When the measured temperature of a channel crosses the respective threshold, a status bit is set in the thermal status registers and the open-drain THERM output asserts. A highest temperature register allows the master to obtain the temperature of the hottest channel.

Posted in app notes | Tagged , , | Leave a comment

App note: Wi-Fi data logger

in app notes by DP | 0 comments


An app note from Microchip on Wi-Fi data logger (PDF!):

Dataloggers are used in a variety of industries, some examples are:

  • Environmental sensors
  • Motor RPM measurements
  • Location tags using GPS
  • Temperature sensors
  • Light sensors
  • Motion sensors

A data logger can be configured in a number of ways depending on the application. This case study covers the following application topics:

  • Point to point setup: In this scenario the module is used to transmit sensor readings, but is not connected to the user’s network. Typically used in remote areas such as maritime sensors, the user can periodically connect via adhoc to the data logger and download the sensor data that was collected.
  •  Network setup: When the module can be connected to an access point, the user has the ability to upload the data as frequently as needed from anywhere in the world through the user’s network.

PWM generator and servo tester with ATtiny45

in DIY by DP | 0 comments


Jan Henrik wrote this Instructable detailing the build of his PWM generator and servo tester with ATtiny45:

This PWM generator also works as servotester, it supports all kinds of servos, which dont need more then 5V

Operating voltage: 5V
Max PWM current: 1 A
PWM frequency (by now) : 500HZ , I am trying to make that changeable, if you know how, let me know :)
High effency
small size
small prize ;)

DIY pick and place machine

in DIY, hacks by DP | 0 comments

photo 5

Pete has written an article detailing his DIY pick and place machine build:

Above is the back side of the machine.  Along the top is a piece of DIN Rail that extends from the left and right of the ShapeOko frame.  This is where the majority of parts are installed.  Below this, you see a grey vertical surface with parts mounted.  This is a long steel L-Bracket, surplus from some IKEA furniture, that I screwed to the ShapeOko MDF work surface.

Free PCB coupon via Facebook to 2 random commenters

in Free PCBs by DP | 2 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 | 2 Comments

Week in (p)review April 18, 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

Programmable VFD display & ticker

in DIY, hacks by DP | 1 comment


Coyt Barringer has been working on a programmable VFD display and ticker project:

The goal was to make a small programmable display so I can quickly check the current Bitcoin or Dogecoin price, see the time, weather, etc as I walk into my room. The display also had to look cool – I tried to make it steampunkish / hipster if you will.
The whole thing is really just a large VFD (Vacuum Fluorescent Display) and a Raspberry Pi, both of which I mounted to a bent metal plate as a stand. There is also a PIR motion sensor which I have setup to put the display to sleep after a set amount of time with no motion in the room. There are green LEDs between the metal plate and the back of the VFD to create a green glow around the edge. The Raspberry Pi is running it’s default debian distro (Raspbian?) and auto connects to wifi on boot, and a Python script controls the VFD through the Raspberry Pi’s serial port.

Posted in DIY, hacks | Tagged , | 1 Comment

RC servo and PID – ‘Autotune’

in DIY, hacks by DP | 0 comments


Stanley Lio‎ is working on a RC Servo and PID autotune project:

The robotic arm built for the magnetic field measurement project leaves several things to be desired.

  • After a new servo is installed, finding the mapping between PWM duration and DH angles is done manually with pen and protractor. I want to automated this.
  • The arm trembles and oscillates at certain poses. I want to be able to tune the PID parameters of the RC servos, and experiment with different control algorithms.

I can use the IMU mounted on the arm to automate these tasks, or even use computer vision. Would be interesting to have the computer auto-tune the PID parameters.
I also want to go one step further and combine computer vision with the arm.
Move the arm with real-time input devices such as mouse, keyboard, gamepad, camera etc.

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

JTAG flashing BCM6348 devices with a Bus Pirate and OpenOCD

in Bus Pirate, JTAG by DP | 1 comment


Lee of Sodnpoo writes:

Having never used JTAG before I thought I’d see what I could do with my new Bus Pirate and one of the old ADSL routers I have lying around – ideally reading/writing to the flash. The v1 BT Home Hub is a Broadcom BCM6348-based device with 32MB RAM, that I’d previously added headers for the serial uart and replaced the bootloader with RedBoot and the OS with openwrt. You can see a small breakout with a TTL level converter and an FTDI uart<->USB on the right, and the Bus Pirate on the left in the picture above.

Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

Posted in Bus Pirate, JTAG | Tagged , , | 1 Comment

DIY laser cutter project

in DIY by DP | 0 comments


Hans Peter of has been working on a Laser cutter project and wrote a detailed explanation on his blog describing the build:

Having seen the crazy-fast development of the printers during the time I’ve had mine, I can clearly see that my printer is not the fastest or the most precise in the league anymore. Most of the newer printers use some kind of lasercut frame or piece somewhere. While I can get to a laser cutter, it takes a lot of time and I’m not guaranteed that it’s available when I need it. so therefore – I want my own. Commercial cutters cost around 45kDKR and up, so that’s a no. Instead, I will be building one on my own.

Posted in DIY | Tagged , | Leave a comment

1.3”OLED with SSD1306 controlled by Bus Pirate

in Bus Pirate, project logs by DP | 0 comments


Markus Gritsch writes:

I wrote a quick Python script to communicate with an SSD1306 driven OLED connected to a PC with a Bus Pirate. The script uses the Bus Pirates raw SPI mode and manages to update the little screen slightly faster than 10 times per second.

Via the project log forum.

Check out the video after the break.

Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.

Continue reading →

Simple electric imp temperature logger

in 3D Model, hacks by DP | 0 comments

2014-01-09 10.20.27

Marcus Olsson of Slickstreamer made this simple electric imp temperature logger with 3D printed case:

I build this temperature logger for my father as a christmas present so he can use his phone to view the temperature at home. The device is build from a electric imp, TMP102 temperature sensor, battery and a charger. It loggs the data to thingspeak.

Hacking a 3D printer into a tattoo machine

in 3D Model by DP | 0 comments


Here’s a cool instructable for a 3D printer tattoo machine:

In october 2013, a famous design school in Paris, ENSCI les Ateliers, hosted a workshop organised by the French Ministry of culture. The idea was to use images, videos and sound fallen in the national pubic domain and use them in a sort of “Mashup”. The event was called Public Domain Remix.

The students had one day (8 hours) to pick their digital material and transform it, hack it or remix it.
Le FabShop, was invited as a digital manufacturing expert to help the students realise their project.
After a short brainstorm, all the teams came up with similar ideas, except one, who really went out of the box with their concept. They had this silly idea of making a machine that could automatically create tattoos taken from a bank of images.

Check out the video after the break.

Via Open Electronics.

Continue reading →

Hacker Camp Shenzhen Day 1: Hot pot dinner

in Hacker Camp Shenzhen, Shenzhen by DP | 0 comments

By ian


Hacker Camp Shenzhen isn’t just about cool markets and amazing soldering techniques, we made food a centerpiece too! Day 1 dinner: Hot pot. Here is the hot pot crew in action! 30 hackers joined us at our favorite hot pot place.

This hot pot restaurant is probably the most popular one in the neighborhood. Five people sit around a charcoal-fired pot filled with boiling broth. Plates of meat and vegetables are delivered all night – just toss in your favorites for a quick boil and eat. Optionally, blend your own dipping sauce at the sauce bar.


Lots of lamb, lots of Tsing Tao, lots of laughter.


The street is still pretty wet, but that didn’t stop us from having fun. People walking by stopped to take photos of all these foreigners.


This restaurant is so popular that it won’t take reservations. So, we came here to eat almost 5 times a week for a month to persuade the owners to rent us the sidewalk for the night.

After lots of begging, one of the owners finally said yes. Frankly speaking, it was only 4 days before the workshop that we sealed the deal.


This is the spicy hot pot team, Gus and Nik are just about to pose, Ian and Akiba are already in full FACE FRAME!

Via Hacker Camp Shenzhen mini-site: Hacker Camp Shenzhen Day 1: Hot pot dinner

The deal with Dirty Cheap Dirty Boards PCBs

in PCB Review, PCBs, site by DP | 17 comments


This sad FACE FRAME! documents the moment Ian found out Dirty PCBs hit Hacker News, Hack a Day, etc. Here’s the story behind our joke PCB site…

A few months ago there were some comments in the forum about various PCB services making ‘crap’ $0.90 boards. Later we posted a picture of our own $0.20 PCB on the blog and the first comment was ‘silkscreen sucks’.  It became an inside joke around here because a few years ago we were all more than happy to pay Olimex $100 for a tiny PCB with no silk…but now people complain about minor things like a smudged silkscreen on twenty cent PCB.

In the forum we joked about about starting a PCB site intended to be crappy: “Dirty Cheap Dirty Boards”. One of our team members, who shall remain nameless, took the joke way too far and made an actual PCB website based on that joke. The site promises cheap and bad PCBs. We used it internally to handle our PCBs, and let a few forum contributors place orders too – easier than doing it all manually.

Here we are, eating hot pot dinner on the street of Shenzhen with the rump end of the hacker camp crew enjoying a Tsing Tao. Phones buzz – order notification. Phones buzz more. And again, and again. Then someone from the HAX group delivers the terrifying news – our little inside joke is on Hacker News. Then it pops up on Hack a Day too.

We hit the comments to say it was a joke and flame the trolls who dissed our flippant attitude (you like it dirty and you’re back for more), but the damage was done.

However, Dirty PCBs wasn’t entirely a joke. The platform combines all of our ideas for a ‘no nonsense’ online ordering platform. No stupid logins with yet another password to remember, no login to get order status, obscene amounts of status updates (email, SMS, Twitter), and a single step ordering process with flat  predictable pricing.

The Dirty Platform is used in two new projects we’re launching. The first is Dirty Circuits – a schematic entry, PCB routing, and footprint building service for open hardware that’s open now. It’s been available privately to some select projects for a while and has been a great success.  Soon, we’ll add Dirty Cables, a way to create custom designed cables from quantity 100. That’s not the end of the Dirty world either, we’ve got more new projects launching soon, all with the goal to help make more and better open source hardware.

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.