Raspberry Pi 2 Web Hosting – Full Email Server & Web Server

LDSrelience shared this video on Youtube!

This is a short video going over a project I just finished to prove that a Raspberry Pi 2 Model B (new as of February 2015) can run a light duty website and low volume email server. I have installed Apache2 for the web server, which takes like 2 minutes for the basic install, and Postfix and Dovecot for the email server. The mail server definitely takes longer to set up but with the detailed, step by step instructions available at the link below it is really easy to do.

Raspberry Pi 2 Web Hosting – Full Email Server & Web Server – [Link]

SK6812 – a new intelligent RGB LED

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Tim discuss about a new RGB LED that appeared on the market:

During the last months, a new WS2812 alternative appeared on the market: The SK6812. I finally managed to get my hands on some of them to take a closer look. In most aspects these devices are basically clones of the WS2812. What is interesting however, is that the manufacturer came up with a couple of new variations of the stock 5050 RGB LED.

SK6812 – a new intelligent RGB LED – [Link]

Eye Diagram Basics: Reading and applying eye diagrams

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Deepak Behera, Sumit Varshney, Sunaina Srivastava, and Swapnil Tiwari discuss about using an oscilloscope to create eye diagrams and quickly evaluate system performance and gain.

Accelerating data rates, greater design complexity, standards requirements, and shorter cycle times put greater demand on design engineers to debug complex signal integrity issues as early as possible. Because today’s serial data links operate at gigahertz transmission frequencies, a host of variables can affect the integrity of signals, including transmission-line effects, impedance mismatches, signal routing, termination schemes, and grounding schemes.

Eye Diagram Basics: Reading and applying eye diagrams – [Link]

Passive Wi-Fi – Bringing Low Power to Wi-Fi Transmissions

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Bryce Kellogg, Vamsi Talla, Shyam Gollakota, Joshua R. Smith have published an research article discussing Passive Wi-Fi  transmission that consumes 3 – 4 orders of magnitude lower power than existing Wi-Fi chipsets.

Passive Wi-Fi transmissions can be decoded on any Wi-Fi device including routers, mobile phones and tablets. Building on this, we also present a network stack design that enables Passive Wi-Fi transmitters to coexist with other devices in the ISM band, without incurring the power consumption of carrier sense and medium access control operations

Passive Wi-Fi – Bringing Low Power to Wi-Fi Transmissions – [Link]

RELATED POSTS

Controlling Arduino using your Voice

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bluehybrid @ instructables.com shows us how to use your voice to control a led light on Arduino. To achieve this he used the 1Sheeld Arduino shield.

This Project is getting start to use arduino with 1Sheeld

In this project we will turn an LED (ON) and turn it (OFF) by Voice

We will say “Open” to turn it (ON) and “Close” to turn it (OFF)

Controlling Arduino using your Voice – [Link]

Portable Adjustable Mini Power supply

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Mixed Output @ instructables.com has build a nice power supply by combining different power modules.

As most of my project involve electronics of some sort, having a good power supply is essential to be able to meet the demand of different power requirements. So I built me a bench-top power supply from an old ATX power supply Unit (PSU) that worked (and still works) great. However I’ve recently noticed some limitations with having a full fledged bench top PSU.

Portable Adjustable Mini Power supply – [Link]

Teardown: Amazon Dash Button keeps you connected

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Brian Dipert @ edn.com has done a teardown on Amazon’s dash button and shows the parts inside.

How much hardware was Amazon able to squeeze into such a diminutive bill-of-materials budget, or perhaps more accurately, how much are Amazon and its consumable-supplier partners subsidizing the initial hardware cost in the hope of plenty of future generated profits? Let’s find out.

Teardown: Amazon Dash Button keeps you connected – [Link]

Sensirion Tiny sensor hones temperature accuracy

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Housed in a tiny 8-pin DFN package, the STS31 digital temperature sensor from Sensirion guarantees accuracy to within ±0.3°C over a temperature range of -40°C to +90°C. A low-cost version, the STS30 achieves the same accuracy over a temperature range of 0°C to +65°C. Both devices are only 0.9 mm high and occupy a footprint of 2.5 × 2.5 mm.

Sensirion Tiny sensor hones temperature accuracy – [Link]

Hardware serial port monitor over WiFi

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This tutorial shows how to connect Arduino to the TX line (of a router, RPI) and display serial data on smartphone over WiFi.

Arduino listens for serial port communication on its hardware serial port. Then it sends every received line of data trough software serial port to ESP8266. ESP8266 puts every received line of data into circular buffer. ESP8266 also runs code for webserver and a website which pools the buffer for new data and displays it on the website. (Sadly there is no websockets support for ESP8266.) To see this serial data all you have to do is open the website (IP) on your smartphone and enable javascript.

Hardware serial port monitor over WiFi – [Link]

DIY Wearable Posture Sensor

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With the help of this wearable device you can improve your posture as it will remind you whenever you slouch. The device is based on ADXL335 accelerometer and Attiny85 microcontroller and a vibration motor will get you notified.

Posture sensors/monitors have been a recurring theme on this blog. They are supposed to remind you of your posture and prevent you from slouching, which can be a cause for back pain and headaches.While my previous sensors were either fixed to a chair or desk, this time I wanted to create a wearable version, that would allow for free movement. As always, one of the main goals was to make this project cheap and easy to reproduce.

DIY Wearable Posture Sensor – [Link]