Today’s 3D model is a 1.8” TFT Backpack board we’ve been playing with lately in the workshop. It’s a cheap 1.8” serial TFT we got of of eBay. The picture was rendered using Kerkythea, sorry about the light-umbrella reflection on the screen.
The board features a PIC microcontroller that controls the TFT, handles USB communication, reads button presses, and has access to a micro SD card.
The models will be published in the Dangerous Prototypes 3D warehouse collection.
Sjaak shared this simple electronic fuse design in the forum:
This is perhaps one of the simplest electronic fuse circuit one can make. The circuit uses only one transistor, one SCR, one push button switch and two resistors.
Via the forum.
XPG is developing an IPv6 stack for the MSP430 microcontrollers using the ENC28J60 Ethernet IC for MAC/PHY. He demonstrates his proof-of-concept by having the MSP430 send HTTP requests to a custom PHP server at a push of a button, as seen in the video above.
Now, as the 2553 only has 512 bytes of RAM I am using an external SPI SRAM chip to provide a bit more storage as an IPv6 address takes up 16 bytes and you can’t get around storing around 4 or 5 of them. Currently, around 2K are used of the SPI ram. Currently supported are basic IPv6 things such as obtaining an address from Router Advertisments (only 1, though), ICMP ping, UDP transmission, and a very simple TCP implementation that support both server and client mode.
The implementation is very rough (especially TCP), so I won’t share it at this time.
Via 43oh.
ARMPIT SCHEME is an interpreter for the Scheme language (a lexically-scoped dialect of Lisp) that runs on RISC microcontrollers with ARM core. It’s being developed at the Fischell Department of Bioengineering of the A.J. Clark School of Engineering at the University of Maryland at College Park. They explain, “The name ‘Armpit’ was selected for this project because it includes ‘ARM’ (as in ARM core MCU) and ‘pit’ (as in kernel, noyau, nucleus, the core of an Operating System (OS)). Armpit Scheme, once loaded, governs the operation of the MCU, and is ‘Scheme to the metal’ in the sense of running without any other OS. It may be thought of as turning the MCU into a rudimentary Scheme machine. The screenshot above shows the system running on a BeagleBoard XM, powered by and communicating via USB. Minicom is used to communicate with the board which reads, evaluates and prints the result of the entered expressions.”
You can find more about this open source code project, as well as download links, on Sourceforge.
Here is an article from Electronic design covering some interesting tips and tricks for high speed ADC layouts:
There is no way to cover all the specifics when designing a high-speed, high-resolution converter layout. Each application is different and sometimes unique. However, these key points will be useful to designers in better understanding their future system designs.
Javier Montaner has released a new Arduino library for the Seeedstudio NFC shield. The new PN532 library uses SPI HW implementation from official Arduino SPI.h library in contrast to the original PN532 library from seeed which uses a dedicated SPI SW implementation in the PN532.h library.
You can download the Javier’s NFC library and supporting docs from GitHub.
Here is another circuit collection from Linear Technology. This one covers power conversion, measurement, and pulse circuits.
This ink marks LTC’s eighth circuit collection publication. We are continually surprised, to the point of near mystifi cation, by these circuit amalgams seemingly limitless appeal. Reader requests ascend rapidly upon publication, remaining high for years, even decades.
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:
Maxim describes various SMPS regulator topologies for battery powered systems. Isolated and non-isolated topologies are covered:
This tutorial presents an overview of regulator topologies for battery-powered equipment. The discussion covers linear regulators, charge pumps, buck and boost regulators, inverters, and flyback designs. The importance of peak current is explained, and schematics of each topology are shown.
As part of the Open Government 2.0 initiative, NASA has been assembling a collection of links to open source code and projects on their open.nasa.gov site. “open.nasa.gov is a collaborative platform for the open government community to share success stories and projects they are working on. The content on this site is written by NASA employees and contractors across the agency. We are excited to highlight the ways that transparency, participation, and collaboration are being embraced by NASA policy, technology, and culture – and the amazing future that becomes possible because of that commitment.”
Among the open source code found there is the Interplanetary Overlay Network (ION) project, Object-Oriented Data Technology (OODT) middleware and a Python based command line Data Productivity Toolkit (DPT) for working on text files.
Via Linux Journal.
Usually capacitive touch interfaces can’t be used with metal coverings, but Microchip’s Metal Over Cap overcomes this limitation:
As a user interface, capacitive touch has several advantages: it is low power, low cost, simple to implement, reliable mechanically, and it allows designers a great deal of freedom in the shape of the buttons. However, for all its advantages, the field effect nature of capacitive touch still has some limitations. 1. Standard capacitive touch systems normally do not work through metal coverings. 2. It requires special software to operate in environments with radiated and/or conducted noise. 3. Reading buttons in the presence of water or other contaminants can be difficult. 4. It is problematic for visually impaired users that rely on Braille. 5. It has trouble detecting a touch through gloves. Microchip?s new Metal Over Capacitive user interface system overcomes all of these limitations without compromising power consumption or design simplicity. This application note describes how to create an interface using the Metal Over Capacitive touch system.
Made changes to Open Hardware Summit presentation based on comments, thanks everyone!
Received second H1N recording device for our workshop video at Sjaak’s place this weekend.
Making contact with New York City hackerspaces for our upcoming visit. If you’re planning to go to Maker Faire or Open Hardware Summit in NYC you are welcome to join our tour of shops and hackerspaces.
Working on ATX PSU v2 using KiCAD.
Check out Alan Yate’s video about the Curious-C Beeper:
When a capacitor is touched to the probe, the probe beeps at a frequency that varies with capacitance. The frequency change is so steep with capacitance that tiny capacitors may be precisely matched or an exact fixed value may be selected to replace a trimmer in a prototype. If the user has reasonably moist skin, simply holding one lead of the capacitor to be tested while touching the other lead to the probe is all that is necessary.
Thanks Matseng! Via the forum.
A13-OLinuXino-WiFi boad (Rev-B) for developers is now available:
Olimex has released the A13-OLinuXino-WiFi boad (Rev-B) for developers.
It can be ordered for EUR 55 (incl. free shipping) via the Olimex web store.
VAT will be added if you have no EU VAT-Id.A13-OLinuXino-WIFI – completely assembled and tested (SD card not included) with WIFI 802.11n 150Mbit WIFI module and 4GB NAND flash
Notice: the VGA output does not work properly, yet!
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 a every week:
Continue reading “Free PCB coupon via Facebook to 2 random commenters”
Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon.
Coming up:
What are you hacking this week?
Frank noticed this article on EEWeb PULSE about Programming With Low-Cost JTAG Tools (PDF!) that references the Bus Pirate:
If you’re not a big fan of building it yourself, then you could use one of the (X)SVF players that are available on the internet. Notable is the Bus Pirate from Dangerous Prototypes. Originally designed as a tool to sniff, monitor, inject or bus protocols like SPI, its open platform has meant that the ‘community’ has developed an XSVF player. This allows a user to convert an SVF file format to XSVF with the tools supplied. The board, which is a very good price, can then be easily re-programmed as a JTAG programmer. You then simply run the right command from your computer and the file is uploaded to the Bus Pirate via USB which then carries out the required toggling of the JTAG lines.
The XSVF tools are a very simple and effective way to program CPLDs and FPGAs. While the Bus Pirate is handy in a pinch, if you’re doing lots of JTAG debugging the Bus Blaster is a much faster and widely supported device for just a couple bucks more.
Thanks Frank & EEWeb! Via the contact form.
Get your own Bus Pirate for $30, including worldwide shipping.
Uwe tipped us to a Stellaris LaunchPad giveaway:
YES! I want to sign up for a Stellaris LaunchPad.
When you sign up for the email alert, we’ll also enter your name in a drawing for one of 25 FREE Stellaris LaunchPads!
You only need to register once. Only one entry per person. We’ll email you on August 31st if you’re one of the lucky winners!
Via the contact form.
Chris from Pyroelectro has posted this tutorial detailing the use of an IR transmitter and receiver break-beam pair to measure the speed of a fan. The IR components are used in conjunction with the Arduino UNO which processes the break-beam interruption counting with the result displayed on a 16×2 LCD display.
You can get the details on this project, along with schematic and Arduino code at Chris’ Pyroelectro website.
Via the contact form.
