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.
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.
Happy Thanksgiving to all our USA friends from DangerousPrototypes!
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 “Linux-based clock radio”
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.
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.
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.
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:
Some stuff:
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.
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:
- Use pullup resistors on all chip select signals.
- Verify tri-state behavior on MISO: use a tri-state buffer chip if necessary.
- Protect bus access with SPI.beginTransaction(settings) and SPI.endTransaction().
Rajkumar Sharma over at Electronics Lab published a new build, a 3 tone siren based on UM3561 IC:
3 Tone Siren project produces Gun Sound, Police Siren and Ambulance Siren effects from a speaker. This project is built around UM3561 IC driving an LM386 audio amplifier to give that extra punch.
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.
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, a messy mix of local dev servers, hardware suppliers, and sweeps coins casinos, 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).
An app note going back to LCD display basics from Microchip.
This application note provides an introduction to the basics of LCD: its construction, physics behind its operation, and the different factors affecting its properties and performance.
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:
Adding a low-cost virtual graphics on embedded application, app note from Microchip.
This application note describes the LCC Graphics Board that enables the implementation of a low-cost controllerless graphic method using a PIC32 microcontroller.
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.
Martin Melchior has been experimenting with switch-selectable configurations for a TP-Link TL-WR703n router. The setup allows for quick changes in configuration dictated by changes in location or circumstances. It allows the router’s use as a Ethernet to WiFi bridge (Access point), since it’s handy to have your own WiFi at a friend’s house or hotel; or to connect a wired Ethernet device to your home WiFi through the router (configured as a WiFi client).
Details can be found on Martin’s website.
Via the contact form.
Steve Chamberlin of Big Mess o’ Wires has written up documentation on his awesome 68 Katy project, a 68000 Linux on a solderless breadboard:
Here’s a look at the final version of the hardware. It took about a week to assemble and wire up all the parts on a solderless breadboard. The heart of the system is a Motorola 68008 CPU, a low-cost variant of the more common 68000, with fewer address pins and an 8-bit data bus. The CPU has 20 address pins, allowing for 1 MB of total address space. It’s paired with a 512K 8-bit SRAM, and a 512K Flash ROM (of which 480K is addressable – the remaining 32K is memory-mapped I/O devices).
Check out the video after the break. Continue reading “68 Katy – 68000 Linux on a solderless breadboard”
Maker Faire Tokyo will be held on November 23rd and 24th! The fair is in its third year and will be held at Tokyo Big Sight!
Mark your calendar!
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:
Continue reading “Free PCB coupon via Facebook to 2 random commenters”
