by drcurzon @ instructables.com:
This is my first Instructable so all criticisms and comments are welcome.
This will show you how to set up a simple wired web server on your Raspberry Pi, with PHP and MySql.
The Raspberry Pi is a good choice for a webserver that will not recieve too much traffic, such as a testing server, or small intranet, as it doesn;t get too hot (so is nice and quiet), and only uses around 5 Watts of power (costing £3.50 a year where I am if it’s running 24/7)
Raspberry Pi Web Server - [Link]
by synthdood @ instructables.com:
I have been an avid electronics DIY guy for many years now, and I have spent a lot of that time struggling to learn how to make my own PCBs. I have tried every technique that I have come across on the internet, from iron-on print outs to dry photosensitive blue sheets. Sometimes I was successful in my efforts to make a passable PCB, but when it was time to reproduce those results, something would go wrong.
After a lot of attempts and frustration, I was determined to find a solution that didn’t result in me sending my files off to a PCB fab house. I use a fab house after I have tested a design on a homemade PCB. I finally found a solution where I can reproduce aesthetically pleasing PCBs by using liquid negative photo-sensitive paint. In this Instructable, I will share with you a technique that I have developed to do this.
DIY PCB using Liquid Photoresist - [Link]
by jschrempp @ instructables.com:
Back in January 2014 I was at a meetup of Baby Boomer Makers at TechShop in San Carlos, California. We were going around the table, each taking a turn to talk about projects we’d like to do. Bob spoke up to describe a problem his elderly mother was having – she couldn’t remember to take her medicines on time every day. Each week Bob found that his mother had either forgotten to take her pills one day, or she had run out too soon because she had double-dosed. Both these problems are frightening. Bob is a retired electrical engineer and said to the group, “I have an idea for a device to help elderly people keep on their medicine schedule. I can make the electronics, but I don’t have a way to make a case for the project.”
The Pill Reminder - [Link]
By Richard Moss @ gizmag.com
Researchers at Rice University’s Laboratory for Nanophotonics (LANP) have developed a new image sensor that mimics the way we see color by integrating light amplifiers and color filters directly onto the pixels. The new design enables smaller, less complex, and more organic designs for CMOS (complementary metal-oxide semiconductor) sensors and other photodetectors used in cameras.
Conventional image sensors work by first converting light into electrical signals, then combining that information with the red, green, and blue color data determined by separate filters (or, especially in low-end cameras, a single filter array that uses a mosaic pattern to interpret colors). But this approach adds bulk to the sensor, and the filters gradually degrade under exposure to sunlight.
Nature inspires color-sensitive, CMOS-compatible photodetector - [Link]
Infrared remote control for home appliances is a popular project among hobbyists and students. Smart Outlet is a similar project that provides an infrared controlled AC outlet to connect any electric appliance and has an integrated timer in it. The appliance can be turned on and off from several feet away using an IR remote. The device is Arduino-controlled and has a LCD display to provide a menu based interface to the user for its operation and settings.
Infra-red controlled smart AC outlet - [Link]
Matt Mets of Blinkinlabs shared a tutorial on making solder paste stencils quickly by hand:
This is a truly quick and dirty method for making solder masks, and is nice because it only requires a few hand tools. It’s great for situations when you want to test a new design or make a single, small run of boards, but don’t want to waste time and money on a professional stencil.
Dirty DIY stencils - [Link]
Triac based Indecent lamp dimmer is a simple circuit and it doesn’t requires additional power supply, works directly with 110V AC or 230V AC. It is a low cost dimmer circuit for adjusting the light brightness of incandescent, Halogen Lamp, Light Bulb load up to 250 W.
Triac based lamp dimmer - [Link]
The LT®8310 is a resonant-reset forward converter controller that drives an external low side N-channel MOSFET from an internally regulated 10V supply. The LT8310 features duty mode control to generate a stable, regulated, isolated output using a single power transformer. With the addition of output voltage feedback, via opto-coupler (isolated) or directly wired (nonisolated), current mode regulation is activated, improving output accuracy and load response. A choice of transformer turns ratio makes high step-down or step-up ratios possible without operating at duty cycle extremes.
100 V Forward Voltage Controller - [Link]
A Geiger counter, also called a Geiger-Muller (GM) counter, is a type of particle detector that measures ionizing radiation. It detects the emission of nuclear radiation: alpha particles, beta particles, and gamma rays by the ionization produced in a low-pressure gas in a Geiger-Muller (GM) tube, which gives its name to the instrument.
A High Voltage generator (U1, U2, Q1, T1, and associated components) powers a GM tube. A pulse from the GM tube is interfaced through Q2 and U1 to pulse-generator U3, which drives a speaker.
Geiger Counter - [Link]