Free PCB coupon via Facebook to 2 random commenters

in Free PCBs by DP | 0 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 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:

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Bus Pirate V4 LCD adapter

in BP v4, LCD by DP | 0 comments


Dave of V-Tech Design wrote an article on how to modify a Bus Pirate LCD adapter for the Bus Pirate V4:

Why do this? At the time of this writing Dangerous Prototypes had not developed a new LCD adapter for the Bus Pirate V4 and I needed one for a project. So why not modify the existing V3 model. I unsoldered the existing header from the Bus Pirate LCD Adapter and wired a 10 pin header cable to the LCD Adapter

Get an LCD adapter for $9.

A development board for the ESP8266-03

in dev boards by DP | 0 comments


Limpkin has developed a development board for the ESP8266-03:

The ESP8266 modules come with a pre-loaded firmware that will accept some commands through their UART interface (connect to wifi, open udp socket, send data to this IP…). Moreover, since Espressif recently released their SDK you can now load your own custom programs using the existing bootloader. To launch this bootloader you just have to connect some IOs to GND in a specific order.
However, anyone wanting to develop a project involving dozens of Wifi nodes has to start from somewhere, eg make a prototype of their future platform. That is why I developed this development board, so the prototyping stage is as simple as possible.
As you can see in the picture below the dev board breaks out all the ESP8266-03 IOs, includes a 3.3V LDO, a USB to UART converter, some logic and a button to automatically start the bootloader.

Check out the video after the break. Continue reading →

CNN coverage of Arduino, open source

in Arduino, News, open source by the machinegeek | 0 comments

In this article Peter Shadbolt, writer for CNN, introduces their readers to the world of open source through his description of the Arduino’s development. While there’s nothing there that Arduino users don’t already know, it’s encouraging to see mainstream news publications giving positive coverage to open source.

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PCB quadcopter frame

in project logs by DP | 0 comments


Elpis over at Embedded Day decided to design and make his own PCB quadcopter frame:

This is my second build and I desired to build the main frame out of PCB instead of plywood like before. I’ve also include the power distribution on the bottom layer of the PCB in order to have a cleaner setup with the power cables!

For more information on this build, visit Embedded Day.

Via the project log forum.

Reversing D-Link’s WPS Pin Algorithm

in reversed by DP | 0 comments


Craig of /dev/ttyS0 wrote an article on reversing D-Link’s WPS Pin Algorithm:

While perusing the latest firmware for D-Link’s DIR-810L 80211ac router, I found an interesting bit of code in sbin/ncc, a binary which provides back-end services used by many other processes on the device, including the HTTP and UPnP servers
I first began examining this particular piece of code with the hopes of controlling part of the format string that is passed to __system. However, this data proved not to be user controllable, as the value placed in the format string is the default WPS pin for the router.
The default WPS pin itself is retrieved via a call to sub_4D56F8. Since the WPS pin is typically programmed into NVRAM at the factory, one might expect sub_4D56F8 to simply be performing some NVRAM queries, but that is not the case
This code isn’t retrieving a WPS pin at all, but instead is grabbing the router’s WAN MAC address. The MAC address is then split into its OUI and NIC components, and a tedious set of multiplications, xors, and shifts ensues (full disassembly listing here)

Details can be found on Craig’s website.

Linux-based clock radio

in DIY, hacks, Linux by DP | 0 comments

IMG_8640 (1)-600

An open-source Linux-based clock radio from SpriteMods:

Ofcourse, a nice PCB with a powerful processor and a nice display only is scrap without the software: especially in this case, it pretty much defines what the device does.

While developing the hardware, I already had made the decision to go with Linux and OpenWRT as an OS, as that’s what runs on the Carambola by default. Using this combination also has the advantages that most of the libraries that can be used on OpenWRT also are available on my desktop machine. That makes it possible to make a version that runs there too, making it pretty easy to debug. Using an established OS also makes it easy to use open-source libraries, meaning you don’t have to re-invent the wheel. In this case, I use libcairo for drawing the user interface, Mongoose as the integrated webserver and jansson as a JSON library, for the API and as storage. To play web streams, the Carambola also runs mpd, which is then remote-controlled using libmpdclient by the clock radio software. This way, a crashing mp3 decoder won’t take down the complete software and stop me from waking up in the morning.

For project details and to download the open source project files visit Spritesmods site.

Check out the video after the break. Continue reading →

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ESP8266 powered web server + LED control + DHT22 temperature/humidity sensor reading

in Chips, hacks by DP | 1 comment


Martin writes:

The ESP8266 System-on-chip (SoC) has recently came out of nowhere and has been taking by storm the IoT DIY world. It is a $4.50 Wi-Fi capable chip that has remarkable specs, obsoleting overnight a number of similar products that are out there. The price factor, availability of SDK and a fast growing community make this chip quite attractive.
The most common usage for the chip so far has been to interface it to MCU and utilize the AT commands that are available in the default firmware, however that is quite an abuse of the power under the hood of the ESP8266. I’ve decided not to use external MCU and utilize the chip itself for a proof-of-concept project:

The project shall be able to

  • Run a HTTP daemon
  • Be configurable through web interface
  • Provide web UI for switching on/off a LED connected to GPIO pin
  • Provide web UI for reading a temperature+humidity sensor (DHT22)

Details and source code can be found on Martin’s website.

Posted in Chips, hacks | Tagged , , | 1 Comment

Simple automatic car battery charger

in hacks by DP | 0 comments


Dilshan Jayakody has published a new build, an automatic car battery charger:

This is modified version of commonly available automatic car battery charger system. I obtain original layout of this charger from one of the commercially available Chinese car battery charger and modified some of the sections of original schematic to improve the performance and stability of the system. This charger is mainly based on LM311 comparator and 2×12V 4A transformer.

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Microcontroller based running light controller

in dev boards by DP | 10 comments


Another project by Rajkumar Sharma over at Electronics Lab, a lights effects board using common bulbs:

This project provides some lighting effect by the blinking pattern of the bulbs connected at its output. Up to 8 Bulbs can be connected in between connector CN2 to CN9 and AC power to control them should be connected at Connector CN10. DC Power should be applied at Connector CN11 in accordance with the polarity marked on this connector. Care should be taken while using this it as it contains Main Power on the board.
We can change the Blink pattern by the press of the SET switch and change the blinking speed by the press of the UP and DOWN keys on the PCB. Fuse F1 will protect the Kit from any possible short circuit and excess current flowing through it.

#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.

Better SPI Bus design in 3 steps

in how-to by DP | 0 comments


Paul over at Dorkbotpdx has written an article on 3 steps to good SPI Bus design:

A much better SPI bus design can prevent conflicts. 3 simple improvements are needed:

  1. Use pullup resistors on all chip select signals.
  2. Verify tri-state behavior on MISO: use a tri-state buffer chip if necessary.
  3. Protect bus access with SPI.beginTransaction(settings) and SPI.endTransaction().
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A Xively logger library for Spark Core

in library by DP | 0 comments


Davide Gironi writes:

Xively (formerly Cosm and before that Pachube) is an on-line database service allowing developers to connect sensor-derived data (e.g. energy and environment data from objects, devices & buildings) to the Web and to build their own applications based on that data.
This library is a modular and configurable Xively data logger, built for Spark Core, usefull to send datapoints to your xively feed.
It comes with a configurable web page, user can set Xively API Key and feed id by browsing the setup page.
One can extend the sample snippet code to create a custom logger using sensors connected to Spark.

Password manager

in project logs, security by DP | 1 comment


Sjaak posted pictures of his password manager build in the project log forum:

I was frustrated by trying to remember my passwords for all my websites and got even more frustrated when i need to change a password again after some months. Dont even to mention the needed complexity of them nowadays. A bit insired by the mooltipass featured on hackaday, but too scared of the complexity and hugeness of it, I decided to roll my own.
Also I’m not a terrorist nor a high placed public person, so I dont need that high encrypted and bulky design. Prolly the NSA would crack this thing in a matter of days (minutes?) but I think it will keep your pr0n logins safe from your little brother ;).
Current design/features:

– Uses the supercheap PIC16LF1454 (+- 1USD/piece) with no need for a XTAL (Clock is derived from USB)
– Uses a small but crystalclear OLED (128×32, I2C).
– Uses an OS USB stack
– Emulates a keyboard (HID) for entering usernames or passwords.
– USB thumbdrive footprint.
– Device is protected by a pincode (securely stored in flash on the uC).
– Simple PC application for updating protected storage (currently compiles on linux and windows).
– 32Kbyte storage for usernames/passes (512 username/passes total).
– External storage is XORed with a pseudo RNG (seed of the RNG is not based on the pincode).


Free PCB Sunday: Pick your PCB

in Free PCBs by DP | 69 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 | 69 Comments

App note: Digital sound recorder with AVR and DataFlash

in app notes by DP | 0 comments


An app note from Atmel, digital sound recorder with AVR and DataFlash (PDF!):

This application note describes how to record, store and play back sound using any AVR microcontroller with A/D converter, the AT45DB161B DataFlash memory and a few extra components.
This application note shows in detail the usage of the A/D Converter for sound recording, the Serial Peripheral Interface – SPI – for accessing the external DataFlash memory and the Pulse Width Modulation – PWM – for playback. Typical applications that would require one or more of these blocks are temperature loggers, telephone answering machines, or digital voice recorders.

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