Using Bluetooth
"Trying to communicate with a remote device with no other familiar protocol? Bluetooth provides an easy answer with well-documented specs and straightforward programming APIs.
Bluetooth programming can solve several annoying problems outside of its principal domain areas. For example, it works well if you're working on a standalone device and you want to configure the device via a custom Bluetooth profile, or you have a device that speaks a standard protocol that your Linux machine doesn't yet support. In this article, I demonstrate how to code your way out of both problems using Bluetooth.
Linux has a mature and capable Bluetooth stack called BlueZ. Many Linux distributions including Ubuntu 10.10 ship with a Bluetooth-enabled kernel as well as a set of profiles that enable your machine to do things like transfer files to and from a Bluetooth-enabled phone.
There are three main steps to making Bluetooth devices communicate:
- Scan: Scan for devices that advertise certain Bluetooth services
- Pair devices: Exchange a key to authenticate the devices and initiate secure communication
- Connect to a service: After the devices are paired, either end can initiate a connection to a particular service.
We'll use built-in tools to accomplish these tasks, and we'll use the BlueZ API to write a program that will communicate with the device. In particular, we'll implement the Headset profile (HSP), which allows your smart phone to use your computer as a headset. Sample code is provided in C."
Wen page link
Exploiting subthreshold MOSFET behavior in analog applications
"Engineers consider many forms of current leakage in electronic systems to be unusable. This thinking is starting to change as designers begin to explore new frontiers in ultra-low-power devices through precise control of subthreshold leakage currents of MOSFET devices for analog applications. Analog engineers can harness the subthreshold-voltage characteristics of MOSFET devices and use them in the nanopower region, opening an array of possibilities for useful and repeatable circuits, ..."
"The ability to operate this type of circuit in nanopower in the subthreshold region can greatly extend battery life by preserving battery power in sleep mode, thus enhancing security abilities. Further, working in the subthreshold region is imperative for unlocking the benefits of nanopower and for driving innovation in energy harvesting and many other fields."
Web page link
Six-Wire Technique Nulls Stray Resistance
"The boss picked you to design equipment to measure in-circuit resistances on circuit boards as they reach the end of a production line, and a colleague suggested you investigate six-wire measurements. But why would you need six wires to measure an in-circuit resistance?'
Web page link
IP-enabled Grid Devices Standards
"Standards are essential to meeting the needs of the Utility industry and energy consumers. Cisco strongly supports standards in all aspects of the Smart Grid. Some of the standards relevant to the Smart Grid end-point devices are shown below in a hierarchy."
Web page link
Smart Grid IEEE 802.15.4g – So Much Optionality
"In my idle moments I've been perusing my copy of the IEEE 802.15.4g draft standard document, which is now out for comment within the IEEE group. Last time, I noted the highlights of the proposal – the many new modulation methods, the different approaches to spread spectrum, the multiplicity of frequency bands, licensed and license-free, and more. The more different ways there are to perform a specific function, the more opportunities there are for interoperability challenges, testing issues, and potential misinterpretation of the specification. All this can lead up to what I call "Smart Gridlock", where the data can't flow easily in any direction. This time, I thought I'd look at the frame (packet) structure, and see what are the similarities and differences to "plain-old" 802.15.4. Let's see what we find.
First, remember that at its heart, 802.15.4 is a protocol developed for low-duty-cycle, mostly sleeping devices, with potentially thousands of these devices in a single network, all sharing the same channel. In 15.4 (2006), there are four Media Access Control (MAC) frame types: Beacon, Data, Acknowledgment, and MAC Command. Let's see how this draft impacts that!"
Web page link
Bitcoin mining spurs massive innovation
Demands of the cryptocurrency economy drive innovation of the technology required for coin minig (see this page for explanation of Bitcoin). What first started as the fairly easy software task on general purpose computers has been moved to a more effective GPU computing. However, with the rising dificulty of the new coin creation the energy cost of GPU computing has reached parity with the economic benefit. New trend has been power efficient approach using specialized FPGA boards.
Here are few examples of the FPGA based minig.
Open Source FGPA Bitcoin Miner - web page link
X6500 Custom FPGA Miner - forum thread link
Icarus FPGA development or bitcoin mining board - web page link
BitcoinFPGA - web page link
Web page link
CERN Open Hardware Repository
"Open hardware for open science
Inspired by the open source software movement, the Open Hardware Repository was created to enable hardware developers to share the results of their R&D activities. The recently published CERN Open Hardware Licence offers the legal framework to support this knowledge and technology exchange."
Introduction web page link
CERN Open Hardware Licence wiki page link
ARMadillo module - project web page link
Infineon launches XMC4000 Cortex-M4 based MCU family
Press release web page link
"XMC stands for "Cross-Market Microcontroller" and means that, due to its configurability, the XMC4000 family is suitable for a wide range of industrial applications. Infineon is using this product to close the performance gap between the 16-bit XE166 family and the 32-bit TriCore™ family. The XMC4000 family is designed to enable scalable, compatible solutions with a high degree of software reusability. The XMC4000 portfolio consists of five series: XMC4100, XMC4200, XMC4400, XMC4500 and XMC4700. These series mainly differ in terms of core frequency, memory capacity and peripheral functions and number of I/O's.
The XMC4000 family has a powerful CPU subsystem, DSP functionality, a floating point unit, a fast Flash memory with only 22ns read time and error correction code (ECC), large SRAM and extended peripheral functions. The extensive range of peripherals includes new timer modules, up to four parallel 12-bit A/D converters with a sampling rate of 70ns and a conversion time of 500ns, up to two 12-bit D/A converters, up to four high-resolution PWM channels (150 ps), integrated delta-sigma demodulator modules and touch button modules. Powerful communication is provided by an IEEE 1588-compatible Ethernet MAC (Media Access Control for Ethernet with time stamp), USB 2.0, CAN and SD/MMC interfaces and up to six serial communication channels which can be individually configured as UART, SPI, Quad SPI, IIC, IIS or LIN using software. In addition, the XMC4000 family offers a fast external bus interface that supports synchronous standards such as SDRAM or Burst Flash, and asynchronous standards such as SRAM, NAND Flash and NOR Flash. "
Web page link
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GoingNative 2012 - streaming live
"GoingNative 2012 is a 48 hour, globally live-streamed technical event for those who push the boundaries of general purpose computing by exploiting the true capabilities of the underlying machine: C++ developers."
"C++11 feels like a new language" says C++ creator Bjarne Stroustrup, who will keynote the event. Tune in now and find out why.
Web page link
Parallel resonance
"A child sits on a swing, feet dangling, perfectly at rest. Give him a gentle push. The child moves forward to a maximum height, reverses course under the influence of gravity, and then swings back and forth. The height of the child's excursions depends on the energy, E1, supplied by your initial push. Damping forces, such as air resistance and the child's foot-dragging, rob energy from each cycle. These damping forces control the ride's duration but have little to do with the size of the initial excursion. Mathematicians define the damping constant, Q, as the ratio of energy stored within the system divided by energy lost per radian of oscillation. The higher the damping constant is, the lower the rate of energy loss, and the longer the ride."
Web page link
Reading ARM Q4 and FY 2011 Results
To get any sens of what new technology is coming from ARM one has to read finacial results but it is an interesing read nonetheless. There are 2 documents available on the ARM investor page link below.
Here are some selected tidbits:
- Atlas / Apollo ARMV8-A architecture "From servers to smartphones Lead Partners signed up"
- Flycatcher is the new MCU processor "Smallest, lowest power ARM processor, Lead Partner signed up" (Who?)
- there are about 850 processor licenses growing by about 100 each year
- in 2011 there were 30+ billion units shippped based on ARM architecure, prediction for 2020 is 150+ billion!
- 1.1 bilion ARM based MCUs shipped in 2011
- ARM based MCU growth rate 80%, marker share 15%
Web page link
SUN Smart Utility Networks
"Smart Utility Networks Smart Wireless Laboratory (SWL) has been engaged in a research and development on a low-power multi-hop data frame transmission scheme to create a long-lived smart utility networks (SUN). In the proposal, turned-off beacons are employed in the superframe structure to reduce power wastage from periodic transmission, and the existing concepts of active and inactive periods in IEEE 802.15.4 MAC are adopted; thus, effective sleep periods for each meter device are assigned. Moreover, by constructing a tree-shaped topology with incoming and outgoing superframes, as defined in IEEE 802.15.4 MAC, multi-hop frame transmission is easily realized based on the topology."
Web page link
Fukushima Robot Operator Writes Tell-All Blog
"An anonymous worker at Japan's Fukushima Dai-ichi nuclear power plant has written dozens of blog posts describing the ups and downs of his experience as one of the lead robot operators at the crippled facility.
His blog provides a window into the complex and dangerous work environment faced by the operators, a small group of young technicians who, like other front-line personnel, must approach areas of high radiation, deploying remote-controlled robots to assist with efforts to further stabilize and shut down the plant's four troubled reactors."
Web page link
Allwinner A10 the new wunderchip of the tablet wars
The Chinese made Cortex-A8 SoC is poised to take over the low cost tablet world as the Wondermedia ARM9 based chips fade away.
Rhombus-Tech is working on a $15 (rumored price, seems too low considering that A10 chip alone is $7 and up) Open source EOMA-68 card based on Open Modular Architecture/PCMCIA web page link
"Allwinner A10 EOMA-68-compliant CPU Card
Features
The Allwinner EOMA-68-compliant module will have the following features:
- Approximately Credit-card size format (56mm x 90mm)
- An Allwinner A10, 1.5ghz ARM Cortex A8
- 1gb of RAM
- at least 1gb of NAND Flash (possibly up to 16gb)
- Operation as a stand-alone computer (USB-OTG powered)
- 2160p (double 1080p) Video playback
- MALI 400MP 3D Graphics, OpenGL ES 2.0 compliant.
- HDMI, Micro-SD, Headphones Socket,
- EOMA-68-compliant interfaces (RGB/TTL, I2C, USB2, SATA-II, 10/100 Eth)
- Expansion Header (similar to Beagleboard, IMX53QSB, Origen etc.)
The 44-pin Expansion Header's interfaces are yet to be finalised, but will include at least:
- 2pins: 1x USB-2
- 8pins: 5-pin AC97 shared with 8-pin I2S Signals.
- 2pins: PWM0 (PB2) and PWM1 (PI13)
- 2pins: IR_TX and IR_RX (also GPIOs, one of which is EINT16)
- 4pins: TV-Out
- 4pins: 4-wire Resistive Touchscreen
- 20pins: 2x LVDS"
For comparison here is an A10 Android 4.0 dev board from Wits-Tech, no word on pricing.
'Pro A10 development board is designed for full blog A10 chip technology designed, compact, full-featured, flexible. Facilitate the business, the Institute for Tablet PC users quickly, home court smart HD network player, car multimedia controller, network security monitoring, and a variety of low-end products such as industrial and medical electronics hardware and software development, debugging platform, or product design reference.
Pro A10开发板是专为全志科技A10芯片而设计，结构紧凑，功能全面，使用灵活。方便企业、研究所用户快速地进行平板电脑、家
庭智能高清网络播放器、汽车多媒体控制器、安防监控网络、以及各种低端工控及医疗电子等产品软硬件开发、调试平台、或产品设计
参考。"
Web page link
Xilinx makes MicroBlaze available in free WebPack ISE
It is the simplified version of the Xilinx MicroBlaze MCS soft-core processor with some limitations and fixed peripheral configuration that is made available but it is interesting to see it as Xilinx pushes ARM based Zynq-7000.
"New in ISE® 13.4, Xilinx introduces MicroBlaze™ Micro Controller System (MCS). MicroBlaze MCS is a complete standalone processor system that is delivered through ISE CORE Generator, intended for lighter-weight controller applications. MicroBlaze MCS delivers a self-contained soft-processor microcontroller with no need for the Embedded Design Kit (EDK), IDS Embedded Edition, or Xilinx Processor Design System (XPS). Now IDS Logic Edition users can configure and utilize a standalone processor-based system."
Web page link
DESCANSO Book Series
With winter taking hold on northern hemisphere there is nothing better then a good book to read over the wekend(s). Here is a hard core engineering series covering all aspects of deep space communication from NASA's JPL Deep Space Communications and Navigation Systems lab.
The whole series (11 volumes) can be downloaded as PDF files from the web page below.
Personal favourites:
Volume 3 "Bandwidth-Efficient Digital Modulation with Application to Deep-Space Communications" and
Volume 9 "Autonomous Software-Defined Radio Receivers for Deep Space Applications"
Recommended!
"The Deep Space Communications and Navigation Series, authored by scientists and engineers with many years of experience in their respective fields, lays a foundation for innovation by communicating state-of-the-art knowledge in key technologies. The series also captures fundamental principles and practices developed during decades of deep-space exploration at JPL. In addition, it celebrates successes and imparts lessons learned. Finally, the series will serve to guide a new generation of scientists and engineers."
Web page link
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