Definitely. 3rd harmonic of the broadcast carrier lands right on top of the 315MHz band.

3rd harmonic is very easy to generate - unless you've spent a *ton* of money on your FM exciter, made every amplifier stage seriously overbiased and underdriven, etc.. you'll have a significant amount of 3rd harmonic coming out of your final amplifier. And it's hard to get rid of, requiring a sharp lowpass or notch on the transmitter output.

And dipole antennas work perfectly fine at odd order harmonics.

I used to design AM/FM broadcast equipment for a living, and making the output of a FM transmitter pass spectrum requirements takes an enormous amount of design effort and testing. "Making a filter to take the harmonics out" is easy to say - but at VHF L's look like C's, C's look like L's and R is never exactly 0 or 50.

Because in my experience, the yield from the chinese Model B factory is 50%.

My first RPi is currently tied up in a work project, so I ordered another model B from Newark. It came in and I fired it up yesterday, no LEDs or any signs of life. Dead.

Then I noticed the main BGA in the center of the card looked a bit askew, looked closer and noticed the BCM2835 was missing. The Samsung DRAM that ordinary sits on top of the '2835 was soldered straight onto the PCB. I understand the part shooter fucking up once in a while and missing a chip, but the board shouldn't have made it out of the factory.

C'mon. I'd rather pay a few extra bucks for something that's most likely going to work, than do what I'm doing now and spending even more bucks mailing the fucking thing back, and crossing my fingers that the replacement works too...

One of my friends did exactly what you're describing - he works on an offshore oil rig, and used a high gain antenna pointed at land to get cellphone service. It worked great... until he came ashore and his phone didn't get a signal.

Turns out the RF connector in the phone is only there for production testing of power/RF compliance - it's only intended to be connected to once, and it's not designed for daily connections/disconnections. The datasheet for one replacement connector we found was only rated for 10 cycles.

Other than sharing the same 2.4GHz ISM frequency band, bluetooth (used for their controllers) and WiFi share basically nothing. In the regular Wii they use separate chipsets, separate antennas, etc. They're stripping out a few bucks worth of hardware. Not to mention, implementing WiFi in a product invariably involves paying a bunch of license fees to patent holders etc - either included in the price of your wifi chipset or paid separately. This adds a couple more bucks to the design.

Take the $99 they're selling the thing for at the store and subtract store markup, shipping, factory tooling, packaging, the rest of the stuff in the Wii box, etc. and you don't have much money to spend on the Wii Mini itself. A few bucks spent adding WiFi could end up being a significant part of the cost.

Honestly, I have to throw some praise at Nintendo for making a game system that's so cheap. My workplace is doing an "adopt-a-family" thing for the christmas season, where employees get together and buy christmas gifts for single parents who can't afford much for their kids. At $99, it's made our shopping list.

Actual use cases I've seen for the Raspberry Pi that I've done myself and seen others do:

- Plug the Rpi into a LAN, and connect it to the serial console of a piece of equipment with a USB to serial cable - old router, telephone equipment, radio broadcast transmitter, fill in the blank. SSH into the thing if you need to get at the console instead of doing a site trip.
- Plug a few sensors into it, run it off a 12V car battery and a +5V automotive USB adapter, and leave it somewhere to log data onto the SD card or a USB stick.
- Plug a USB hard drive into it, and use it as a low power torrent downloader, instead of keeping your desktop PC powered up when you're not home.

It's a tiny, $25 linux machine. Possibilities are endless.

And in other news, Arduino cards have a 16MHz 8-bit processor with mere kilobytes of both RAM and flash. And despite making a 1980s suitcase computer look fast, they've proven themselves to be fully capable of running all sorts of awesome things that hobbyists have been using them for.

What's your point again?

I worked on a system similar to this for a man with an prosthetic arm. We stuck a temperature sensor in the finger of the prosthetic hand, and used a small thermoelectric plate which contacted his skin where the prosthetic attached to him. The back side of the peltier plate was glued to an aluminum bar acting as a thermal source/sink, and the front side had a small stainless plate acting as the contact point with a second temperature sensor bonded to it for feedback. Using a microcontroller and a bit of simple hardware, we made the peltier plate temperature equal to the temperature detected at the finger. With some limits, of course.

The man went from having a plastic arm to having something that *felt* like an actual part of his body again. He described going home and touching his wife's face, and almost breaking down crying - it felt pretty good to hear that, especially since it only took us a few days to design/build the thing.

Anyway, it ran off three NiCd AA batteries and had a battery life of about 24 hours - he'd plug it in to charge when he went to bed, and it would easily last until the next charge cycle. These days thermoelectric devices are more efficient, batteries are a lot better and microcontrollers have much better power consumption.

There's a few things that make a system like this fairly low power:

- You don't need a big contact area to get the sensation of temperature across to the user - you don't need to heat or cool their whole hand. Half a square centimeter is plenty if you put it at a fairly temperature-sensitive part of the hand, such as where your fingers meet your palm. It'll feel weird at first but the 'immersion' feeling will eventually set in.
- There's only a narrow range of temperature that you have to drive the contact plate to. You don't need to do 0 to 50 degrees C, and I fully expect Sony to restrict the range to +-10C at most for liability reasons, not to mention practical reasons.
- Skin isn't *that* thermally conductive.

So if your contact plate is sized small and only within a few degrees of body temperature, you're probably only moving half a watt at most between the hand from the contact plate.

Secondly, I seriously doubt the thermal "immersion" effect will be running all the time, probably only acting on 'events' the game - walking indoors/outdoors (pulse of hot/cold), picking up a weapon from the ground (cold), getting hit with a fireball (hot), falling into water (cold), etc. Much like vibration motors in controllers don't run all the time.

End result is that running the thermoelectrics won't take that much power, and sinking/sourcing heat from within the controller shouldn't be that hard. Overall, seems pretty practical to me.

Something to consider - I've replaced the MicroUSB connector in my cellphone *twice*. The phone would work for about a year, then it would go flaky - you'd have to wiggle the connector a few times for the phone to reliably charge, and sometimes I'd go check on it and it wouldn't be charging - and it would happen with different cables. Supposedly these things are rated for 10,000 cycles, but I haven't seen it. Maybe my phone does something it shouldn't, like spark the +5V pin when the connector is plugged in. *shrug*

Secondly, I've caught the cord of my phone multiple times and pulled it off the desk onto the floor - and my cats/dogs have probably done it more times than I have.

Though there's an efficiency loss in wireless charging versus conductive charging, I wonder if there's an efficiency gain that exists in less phones being repaired/replaced because of damage related to conductive charging.

(Note that this is not a well thought out, researched argument - just a dumb thought.)

Do this. Talk to the math teachers at your school, find out if they've got any poor students that need them. And find out there's any other schools in the area that would have a use for them.

There's lots of single parents and otherwise poor families that can barely scrape together school supplies for their kids, let alone buy the graphic calculator that they would need to get into a precalc or AP math. Something simple like one of these old calculators could turn a kid's life around. Seriously.

I'm suspecting that the BMW is "password protected" in a way (unique knowledge required to get into the car's ECU - PIDs to hit, passphrases, etc) but if the car thief that knowledge then it's essentially open anyway.

Pretty much the only way you'll make a perfectly secure system is by putting the equivalent of a TPM chip in the car and using a cryptographic channel between the car and BMW themselves. Do authentication at the garage and employee levels, and have BMW log everything that happens to every car it talks to, so any malicious use gets recorded and you can figure out who enabled your car to get stolen. Do code signing in the ECU so they can't reprogram the ECU to run different code, authenticate the ECU against other modules in the car so they'd have to basically swap every module in the car... and the list goes on.

But fuck that. I want a car I can maintain. I bought a $300 "VAG-COM" cable for my VW which lets me access pretty much everything computerized going on in the car, and it has been endlessly useful - it's easily paid for itself by allowing me to do my own maintenance.

I would not be surprised at all if there's some way for a person with the same tool to disable the immobilizer in my car, hotwire the car and steal it. But I'm content with that - the odds of having my car stolen by geeks with scan tools is pretty low, and even if it does happen, I'm pretty sure auto theft insurance ends up costing less than paying for dealer-only maintenance on a german car.

Besides, they'd just invent a better car thief. If they completely lock down a car as I've described, someone would end up stealing a car by hooking up a Megasquirt system just to prove a point...

Actually, the OBD-II specification mandates that you provide a certain set of PIDs without any access restrictions.

As long as that functionality is there, you can do whatever else you want with the port - including locked down, proprietary things. Pretty much car manufacturer out there does this.

Whoever wrote this article needs a smack upside the head. The BBQ Guru controllers are intended to control the temperature of charcoal smokers, and won't do anything for you if you're grilling. I s'pose you could get one to work on a Weber kettle if you really wanted to, but at that point you're cooking with a grill, not grilling.

Anyway I'm using BBQ Guru's PartyQ unit on my Weber Smokey Mountain. I'd recommend the thing almost as much as the WSM itself.

There's a few issues with smartphone screens. Given enough effort you can make pretty much anything work, but here's what you'll be up against:

- Knowing what all the pinouts/connectors/voltages/signal levels are.

- Data format: Most of these screens require a proper graphics controller to drive them, capable of clocking RGB data out of a framebuffer into the panel at a pixel clock of several MHz. You might be able to do this with a PIC32, but your code will be blasting data at the panel 99% of the time. You're in the territory of ARM7/ARM9 processors with SDRAM hanging off them when you're making a bare RGB LCD panel work.

- Power: You'll likely have to generate a backlight voltage, and possibly even bias voltages for the LCD panel itself. The LCD may also run at a different voltage node (3.3V or less) while your AVR might end up being 5.0V.

- Touchscreen: Resistive touchscreen isn't too hard to manage. If it's a capacitive touchscreen you might be able to wire it up to an AVR and use their QTouch libraries to make it work. But I'll warn, prototyping a capacitive touch system can be an exercise in frustration - it's not bad when everything sits in one place on a PCB, but you can't breathe on an airwired capacitive touch system without screwing it up.

Honestly, you're best off finding a "smart LCD" with a built-in controller, with a simple SPI/UART/8-bit-parallel/etc interface. Adafruit has an Arduino compatible one up on their site which might be a good starting point, I'm sure there'll be plenty of other suggestions posted here.

Or hell, you're better off keeping the smartphone whole and finding a way to reprogram it to do what you want.

- Grab a couple books on C/C++ and Verilog. I highly recommend "Fundamentals of Digital Logic with Verilog Design", great for both learning and for reference. For C/C++, I've always been a fan of the Sam's "Learn __ in 24 hours" books.

- Get yourself a FPGA development card, so you can get some "hardware play" in and familiarize yourself with some development tools. I have an Altera DE1 educational card that's a few years old, but it's got endless blocks on it (displays, LEDs, buttons, flash, SDRAM, VGA, sound... you name it) which makes it a great little card for embedded system learning. There's a whole set of Verilog and Nios (embedded processor) tutorials available for it, and lots of online hackers who have ported x86 processors (Zet project), hardware emulations of the NES, etc... to it. Xilinx and Actel also make some nice evaluation boards that seem to be targeted fairly often by hobbyists.

Other than that... you can study the heck out of wire protocols, but you'll probably forget everything you learn unless you end up implementing it. You're better off trying to learn as many general things as you can - how to create well organized C/C++ and Verilog code, making your designs meet timing and such - so that if you end up having to implement something, you've got the basics already in place and don't need too much incremental learning. Also if you have some fun ideas for FPGA projects, implement your heart out - that sort of stuff looks great on a resume.

Good luck!

Don't buy your CFLs at Walmart, the grocery store, etc - the Sunbeam/Great Value/etc bulbs that you find at those kinds of stores are shit.

Buy professional CFL bulbs. Hit up the GE or Osram/Sylvania online product catalogs, write down some part numbers with the size/color temp/lifetime that you want, and call up a local industrial/lighting supplier - Harris & Roome is my go-to place here in Canada.

My house is full of GE "FLE10HT2/827" bulbs, 40W equivalents that pull 10W, have a warm color temperature (2700K) and have a 12000 hour lifetime. Which I can believe - I bought a case of these bulbs about 4-5 years ago when I swapped out every incandescent I could find, I still have plenty of them left, and I honestly can't remember the last time I changed a lightbulb in my house - it's been years.