[ElectronUpdate] has posted many great reviews of commercial LED bulbs that one can purchase to replace standard E26 incandescent light bulbs. In his reviews he evaluates the light emitting performance and does a thorough and detailed teardown, evaluating and understanding the circuit technologies used. For the light emission evaluation he uses a light meter and some homemade graph paper to plot the lumens at different angles. Flicker is easily evaluated using a solar panel from a discarded solar path light connected to his oscilloscope. Any flicker will show up quite nicely and can be measured. Of course a kill-a-watt meter makes an appearance in most reviews to read watts and power factor.
Recently [ElectronUpdate] wanted to understand the meaning of CRI which is advertised on many of these commercial LED packages. CRI stands for color rendering index and deals with how colors appear when compared to a natural light source. After doing some researching he found that a CRI over 80 is probably good for LED lighting. The next dilemma was how to measure CRI without expensive scientific equipment. He found a website that we have featured before with free software and instructions on how to build a spectrometer. The web instructions include building a meter box from paper but he found it was much more reliable if built out of wood. We’ll let you follow [ElectronUpdate’s] recommended build if you like, but you’ll need a few items which he does detail.
After a short calibration procedure the final rig will measure power spectral line densities of your light source. [ElectronUpdate] is promising more details on how the colorful measurement data can be related to CRI ratings, but you can get a jump on the details at Full Spectrum Solutions. We also recommend you browse through all of [ElectronUpdate’s] LED bulb reviews on YouTube if the progressing performance and innards of LED bulbs fascinates you as much as it does us.
One thing very common to all of us is our reliance on operating systems in our hobby life. If that OS is Windows then you could be in for quite a shakeup with Windows 8. Many readers are Linux or Apple users and couldn’t care less if Microsoft is releasing an entire paradigm shift in desktop navigation. However, you just might find yourself facing this new OS and you’ll look like you’re on training wheels if you don’t get acquainted now, and considering the number of computers being released with Windows 8 its inevitable that day will come soon.
So if you haven’t been behind the wheel of Windows 8 then checkout [Steve’s] Windows 8 Survival Guide from the Guru Brew Tech Show. This is an excellent overview of the new touch screen navigation methods you’ll find in the Windows 8 desktop including hotspots, charms and tiles to name just a few. You’ll also learn tips to get around with a mouse and keyboard. It’s not a complete tutorial on using Windows 8 but you’ll at least know how to navigate, search for apps, work with multiple apps and find tools like task manager, control panel, file explorer as well as your familiar desktop.
Follow the break to watch the short survival guide video.
Continue reading “GuruBrew’s 15 minute Windows 8 survival guide”
In the market for a software defined radio? [Taylor Killian] wrote a comprehensive comparison of several models that are within the price range of amateurs and hobbyists.
You can get started with SDR using a $20 TV tuner card, but there’s a lot of limitations. These cards only work as receivers, are limited to a small chunk of the radio spectrum, and have limited bandwidth and sample rates. The new SDRs on the market, including the bladeRF, HackRF, and USRP offerings are purpose built for SDR experimentation. You might want an SDR to set up a cellular base station at Burning Man, scan Police and Fire radio channels, or to track ships.
[Taylor] breaks down the various specifications of each radio, and discusses the components used in each SDR in depth. In the end, the choice depends on what you want to do and how much you’re willing to spend. This breakdown should help you choose a hacker friendly SDR.
Stop whatever you’re doing and get this book. I’ve just finished reading it and I have to say that [Wendy] and [Mikey] could easily be the poster children for modern day hacking, and this book could be the manual for a life built on hacking.
When I visited [Wendy] and [Mikey] last year I was blown away. Their little homestead was a veritable smorgasbord of hacks. Everywhere I looked, things were cobbled together, modified, repaired, and improved. There wasn’t a single piece of their lives that wasn’t somehow improved by their efforts to play an active role in their own living.
That sounds a bit cheesy I know. We all play an active role in our lives right? Sure. But what they have done is created a hacker’s homestead. My projects tend to live on my workbench, occasionally poking into my daily life, but they went were there was virtually nothing and hacked together everything they found they needed. Their life is their workbench.
Continue reading “Book Review: The Good Life Lab”
We originally heard about the FemtoDuino last year. It looked good enough and tiny enough, but we didn’t really have a need for it. Recently though, we started on a new project (which you can follow on the forums!) which required an easy modification to an existing circuit. Space and weight were quite important so we decided to pick up a couple femtoduinos at $25 each, and give them a try.
Continue reading “Hands on with the super tiny arudino: FemtoDuino”
For those of you that can’t make a decision between buying an Arduino and a PIC processor, [Brad] has come up with a novel solution, the PICnDuino. We’ve featured him before with his [Retroball] project, but this time Brad has been full funded on Kickstarter, and is pre-selling boards for delivery in March.
[HAD], specifically I, was fortunate enough to be sent one of the boards to try out early. I’ve worked with an Arduino before, but never a PIC processor, so read on to see if it was actually as easy as the tutorial video (at the end of the article) would have you believe it is to get started. Continue reading “The PICnDuino Review”
Years and years ago, someone gave me this book as a gift. [John Knittel], a co-author thought I might find it amusing. The book, titled The Dangers of Computer Hacking, is a grade school level breakdown of, well, computer hacking and the dangers thereof. At the time, I thought it was rather fun and amusing. Since then, it has sat on my shelf without much action.
Last weekend, however, my 8 year old son was building perfectly spaced shapes for his slinky (new plastic slinkies suck) and found this book. I snatched it up and read through it real quick. The realization came to me that though this is somewhat tongue-in-cheek(check the topics on the back cover), this book is actually a fantastic reference for the un-initiated.
Continue reading “Book Review: The Dangers of Computer Hacking”