This application details how a dual-channel LDO may be used to provide a dynamic voltage scaling output. This function is useful when powering microcontrollers that have a wide operating voltage range: it is advantageous to lower the operating voltage of the MCU in order to achieve lower power consumption (when possible).
The MSP430G2001, for example, has a supply voltage range that varies depending on the system frequency and programming modes. As an example, when the system frequency is 1MHz and flash memory programming is not required, the supply voltage range spans from 1.8V to 3.6V. However, if flash memory programming is required, the supply voltage range contracts to 2.2V to 3.6V.
Dynamic Voltage Scaling with a Dual LDO - [Link]
by Colin Jeffrey @ gizmag.com:
For the first time in history, a prototype radio has been created that is claimed to be completely digital, generating high-frequency radio waves purely through the use of integrated circuits and a set of patented algorithms without using conventional analog radio circuits in any way whatsoever. This breakthrough technology promises to vastly improve the wireless communications capabilities of everything from 5G mobile technology to the multitude devices aimed at supporting the Internet of Things (IoT).
World’s first fully digital radio transmitter built purely from microprocessor technology - [Link]
Sine wave oscillator using LM741, a project by A.M. Bhatt of EngineersGarage:
There are different kinds of Sine wave oscillators based on the components used or based on the output frequency that they generate
1. Based on components means if they produce oscillation using resistors (R) and capacitors (C) then they are called RC oscillators and if they use inductor (L) and capacitor (C) then they are termed as LC oscillators
2. Based on output frequency means if they generate frequency in audio range (20 Hz – 20 KHz) then they are Audio Frequency (AF) oscillators. If they generate frequency in low range (100 – 200 KHz) then they are called Low Frequency (LF) oscillators and last, if they generate frequency in high range (in MHz or GHz) then they are termed as High frequency (HF) or Radio Frequency (RF) oscillators.
I am presenting here two such sine-wave oscillators that uses RC components to generate oscillations and they can generate frequency in AF range as well as RF range. The two oscillators are
1. RC phase shift oscillator
2. Wien bridge oscillator
Sine wave oscillator using LM741 - [Link]
Determine the values of the node voltages va and vb for the circuit shown in the figure. The first node equation: the voltage source voltage is related to the node voltages by vb- va = 12 => vb = va + 12. To write the second node equation, we must decide what to do about the voltage source current. KCL can be applied to the problem to generate the 2nd node equation : va/6 + vb/3 = -2. In summary, the node equations are vb – va = 12 and va/6 + vb/3 = -2. Solving the node equations gives va = 12 V; and vb = 0V.
Supernodes - [Link]
New communication module WIZ550WEB offers interesting possibility how to get any device on the web.
To administrate devices through a web interface is simple, fast and comfortable. Also can be added, that it´s a solution that saves time and money and in a vast majority of cases it´s beneficial for a producer and also a customer. Besides common “network devices” for example for data acquisition (telemetry – when we want a device to send measured data), a network connectivity is still more used at devices, whose functionality is not dependent on a web connection. Usually here belong devices, where this “extra functionality” brings several advantages.
Example of such device can be for example a heating boiler, where a user can comfortably monitor its operation and change temperature and in case of a required service a producer can diagnostic the device remotely – without a costly personal inspection.
Novelty in this field is the WIZ550WEB module based on the W5500 chip (10/100 Mbps) from company Wiznet and the STM32F103RBT6 MCU. Hardwired core is highly stable and resistant to attacks. By means of the WIZ550WEB module you can use 16 digital I/O pins and 4 analogue inputs. It also supports serial configuration via AT commands.
The simplest way to start is to use a rich-featured development board Wiz550WEB-EVB with 8 output relays, 8 digital inputs with optocouplers (TLP290-4) and 4 analogue inputs (0-12V).
With the WIZ550WEB module you’re immediately on the web - [Link]
Amy Norcross @ edn.com
Researchers from several universities, including the Georgia Institute of Technology, are working on a keyboard that can isolate typing patterns — such as pressure applied to each key and the time spent between strokes — to accurately identify users. Their findings were published in the journal ACS Nano.
Four layers of transparent film on the device, including polyethylene terephthalate, indium tin oxide, and fluorinated ethylene propylene, harvest and collect energy from the user’s fingertips. “This intelligent keyboard changes the traditional way in which a keyboard is used for information input,” said Zhong Lin Wang, a Regents professor at Georgia Tech’s School of Materials Science and Engineering. “Every punch of the keys produces a complex electrical signal that can be recorded and analyzed.”
“Smart” keyboard knows who’s typing - [Link]
PiJuice is the ultimate module for all portable Raspberry Pi projects. Includes many fun maker projects and a solar power version too!
As one of the smallest systems around there’s so many amazing things you could do with the Raspberry Pi if it was self-powered and portable. With PiJuice we want to provide not only the best portable hardware/software solution, but also a set of inspiring and affordable guided projects for fun, learning, and breaking out the Pi into the real world.
For the past year we’ve toiled and sweated over the technical minutiae of PiJuice so you don’t have to.
- Onboard 1400 mAh “off the shelf” Lipo battery (with support for larger Lipo Battery up to 5000 mAH+) to last up to 24 hrs + in constant use!
- Full UPS (Uninterrupted Power Supply) solution.
- Integrated RTC (Real Time Clock)
- On board intelligent on/off switch
- Low power deep-sleep state with wake on interrupt/calendar event
- Programmable multi-colored RGB led
- Full power management API available to Raspberry Pi OS with auto shutdown capability when running low on batteries
- Raspberry Pi HAT compatible layout, with on board EEPROM for easy plug and play operation
- Low profile design, to fit inside lots of existing Raspberry Pi cases!
PiJuice – A Portable Project Platform For Every Raspberry Pi - [Link]
2 channel Relay driver project can be controlled by feeding 2-12V trigger voltage, Very useful project for application like Micro-Controller based projects, Remote controller, Lamp on Off, and any circuits which required isolated high current and high voltage switching by applying any TTL or CMOS level voltage. Two LED works as operation indicator while in , 3 pins screw terminals to connect load and provides both normally open and normally closed switching.
Input: 12 VDC @ 84 mA
Output: Two SPDT relay
Relay specification: 5 A @ 230 VAC
Trigger level : 2 to 12 VDC
Header connector for connecting power and trigger voltage
LED on each channel indicates relay status
Power Battery Terminal (PBT) for easy relay output connection
Four mounting holes of 3.2 mm each
PCB dimensions 49 mm x 68 mm
2 Channel Relay Board - [Link]
Whether he really said that or not is still up for debate. The quote appeared at the beginning of an editorial written by James E. Fawcette published in the April 29, 1985 issue of InfoWorld and the was attributed to a certain William Gates, chairman of Microsoft in response to a question about why PC-DOS had an upper memory limit of 640 KB.
Well, things move on and at the Mobile World Congress in Barcelona SanDisk Corporation introduced the ‘200GB SanDisk Ultra microSDXC UHS-I card, Premium Edition’, which is currently the world’s largest capacity microSD card for use in mobile devices. This comes one year after they introduced the 128 GB SanDisk Ultra microSDXC card.
According to Christopher Chute, Vice President, Worldwide Digital Imaging Practice, IDC “Seven out of 10 images captured by consumers are now from smartphones and tablets. Consumers view mobile-first devices as their primary means for image capture and sharing, and by 2019 smartphones and tablets will account for nine out of 10 images captured,” This high capacity card is suitable for Android smartphone and tablet users and the Premium Edition microSD card combines the world’s highest capacity with fast transfer speed of up to 90MB/s. The 200GB SanDisk Ultra microSDXC UHS-I card, Premium Edition, has a ten-year limited warranty and will be available worldwide in Q2 at an MSRP of $399.99.
640 K ought to be enough for anyone… - [Link]