Not Quite 101 Uses For An Analog UHF TV Tuner

July 11, 2016 by Jenny List 26 Comments

Young electronics hackers today are very fortunate to grow up in an era with both a plethora of capable devices to stimulate their imagination, and cheap and ready access to them. Less than the price of a hamburger meal can secure you a Linux computing platform such as the Raspberry Pi Zero, and a huge choice of sensors and peripherals are only an overnight postage envelope away.

Casing back a few decades to the 1980s, things were a little different for electronically inclined youth. We had the first generation of 8-bit microcomputers but they were expensive, and unless you had well-heeled parents prepared to buy you a top-end model they could be challenging to interface to. Other electronic parts were far more expensive, and mail order could take weeks to deliver the goods.

For some of us, this was not a problem. We simply cast around for other sources of parts, and one of the most convenient was the scrap CRT TV you’d find in nearly every dumpster in those days before electronic recycling. If you could make it from 1970s-era consumer-grade discrete components, we probably did so having carefully pored over a heap of large PCBs to seek out the right component values. Good training, you certainly end up knowing resistor colour codes by sight that way.

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Challenge Accepted: Automation

July 11, 2016 by Mike Szczys 10 Comments

Today marks the beginning of the Automation Challenge round for the 2016 Hackaday Prize. We want to see what you can create that automates life. It’s a terrifically fun jumping off point for a project, and done just right, it can score you some amazing prizes.

Technology can make life better and automation is one place that is about to see huge expansion. This is a chance to put your mark on the future by envisioning, prototyping, and explaining your ideas. The animated image at the top of this post is a perfect example of how fun automation builds can be. It’s the part of the Sunday Morning Breakfast Machine which steeps the tea. We covered this Rube-Goldberg like device a few weeks ago. About 1,000 hours went into building a completely automated breakfast machine.

Building something whimsical is fine for entering this round — a lot of discovery happens when having fun with interesting ideas. But there is plenty of room for serious builds as well. Technological development has always included iterating on automation; asking and answering the question of how can we do more with less effort.

For instance, you can boil coffee in a pot but then you have to use some filtering technique to sequester the grounds. You can use a French press but that this hasn’t saved you much effort. So someone invented the percolator but you still must watch that you don’t burn your brew. From there we have espresso machines and drip brewers that both regulate how much water is used and at what temperature (in addition to keeping the grounds separate). And now we’re seeing single-unit machines like Nespresso and Keurig which make everything a one-step process, if you’re happy with the pods they sell you. I like to refill my own pods, which lets me choose my own grind. I’d love to see someone automate this entire process of cleaning, grinding, filling and presenting a reusable pod. That would make a great entry and help move more people away from disposable plastic/metal.

All I see when I look around me are ways that life should be more automated, and I bet you have the same proclivity. Now you have a reason to take on the challenge. Automate something and enter it in the Hackaday Prize. Twenty of those entries will be awarded $1,000 and move on to vie for the grand prize of $150,000 and a residency at the Supplyframe Design Lab in Pasadena, plus four other huge top prizes.

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STM32 And FPGAs In A Tiny Package

July 11, 2016 by Brian Benchoff 18 Comments

Slowly, very slowly, the time when we don’t subject embedded beginners to AVRs and PICs is coming. At a glacial pace, FPGA development platforms are becoming ever more capable and less expensive. [Eric Brombaugh] has been playing around with both ARMs and FPGAs for a while now and decided to combine these two loves into a single board that’s capable of a lot.

This board is fittingly called an STM32F303 + ice5 development board, and does exactly what it says on the tin. There’s an STM32F303 on board providing a 32-bit CPU running at 72 MHz, 48 kB of SRAM, a quarter meg of Flash, and enough peripherals to keep anyone happy. The FPGA side of this board is a Lattice iCE5 with about 3k Look Up Tables (LUTs), and one time programmable non-volatile config memory.

The connections between the ARM and FPGA include a dedicated SPI port, and enough GPIOs to implement full-duplex I2S and a USART. Like all good projects, [Eric] has shared all the files, schematics, and BOMs required to make this board your very own reality, and has provided a few links to the development toolchains. While the FPGA is from Lattice’s ice40 family, it’s not supported by the Open Source Project Icestorm toolchain. Still, it’s a very capable board for ARM and FPGA development.

The Dubious Claim Of A World Helium Shortage

July 11, 2016 by Elliot Williams 76 Comments

If you’ve been reading the news lately, you doubtless read about the find of a really big new helium gas field in Tanzania. It’s being touted as “life-saving” and “game-changing” in the popular media, but this is all spin. Helium is important for balloon animals, scientists, and MRI machines alike, but while it’s certainly true that helium prices have been rising steadily since 2000, this new field is unlikely to matter all that much in the grand scheme of things.

The foundation of every news story on helium is that we’re running out of the stuff. As with most doomsday scenarios, the end of the world’s supply of helium is overstated, and we don’t just mean in light of the new Tanzanian field. Helium is the second-most abundant element, making up 24% of the total mass of the universe. And while the earth has a disproportionate amount of heavier elements, helium is in rocks everywhere. It’s just a question of getting it out, and at what price that’s viable.

So while we’re stoked that the era of (relatively) cheap helium can continue onwards for a few more years, we’re still pretty certain that the price is going to continue to rise, and our children’s children won’t be using the stuff for something so frivolous as blowing up party balloons — it’ll be used primarily, as it is now, where it’s more valuable: in science, medicine, and industry.

Let’s take this moment to reflect on the economics of second-lightest element. Here’s to you, Helium!

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What’s Special About Fifty Ohms?

July 11, 2016 by Al Williams 28 Comments

If you’ve worked with radios or other high-frequency circuits, you’ve probably noticed the prevalence of 50 ohm coax. Sure, you sometimes see 75 ohm coax, but overwhelmingly, RF circuits work at 50 ohms.

[Microwaves 101] has an interesting article about how this became the ubiquitous match. Apparently in the 1930s, radio transmitters were pushing towards higher power levels. You generally think that thicker wires have less loss. For coax cable carrying RF though, it’s a bit more complicated.

First, RF signals exhibit the skin effect–they don’t travel in the center of the conductor. Second, the dielectric material (that is, the insulator between the inner and outer conductors) plays a role. The impedance is also a function of the dielectric material and the diameter of the center conductor.

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Put A Reverse Engineered Power Meter In Your Toolkit

July 11, 2016 by Elliot Williams 22 Comments

It seems that one can buy cheap power meters online and, well, that’s it. They work just fine, but to use them for anything else (like datalogging or control or…) they need a bit more work. The good news is that [Thomas Scherrer], alias [OZ2CPU], just did that reverse engineering work for us.

Inside these budget power meters, you’ll find an LCD driver, a power-monitoring chip, and an STM32F030, which is a low-cost ARM Cortex M0 chip that’s fun to play with on its own. [Thomas] traced out the SPI lines that the power-monitoring chip uses to talk to the microcontroller and broke in to snoop on the signals. Once he got an understanding of all the data, tossing an ATmega88 chip on the SPI line lets him exfiltrate it over a convenient asynchronous serial interface.

If you’re going to do this hack yourself, you should note that the internals of the power meter run at line voltage — the 3.3 V that powers the microcontroller floats on top of the 230 V coming out of [Thomas]’s wall plug. He took the necessary precautions with an isolation transformer while testing the device, and didn’t get shocked. That means that to get the serial data out, you’ll need to use optoisolation (or radio!) on the serial lines.

Now that we know how this thing works on the inside, it’s open-season for power-management hacks. Toss a mains socket and an ESP8266 in a box and you’ve got a WiFi-logging power meter that you can use anywhere, all for under $20. Sweet.

Hackaday Prize Entry: Reverse Engineering Blood Glucose Monitors

July 10, 2016 by Gerrit Coetzee 26 Comments

Blood glucose monitors are pretty ubiquitous today. For most people with diabetes, these cheap and reliable sensors are their primary means of managing their blood sugar. But what is the enterprising diabetic hacker to do if he wakes up and realizes, with horror, that a primary aspect of his daily routine doesn’t involve an Arduino?

Rather than succumb to an Arduino-less reality, he can hopefully use the shield [M. Bindhammer] is working on to take his glucose measurement into his own hands.

[Bindhammer]’s initial work is based around the popular one-touch brand of strips. These are the cheapest, use very little blood, and the included needle is not as bad as it could be. His first challenge was just getting the connector for the strips. Naturally he could cannibalize a monitor from the pharmacy, but for someone making a shield that needs a supply line, this isn’t the best option. Surprisingly, the connectors used aren’t patented, so the companies are instead just more rigorous about who they sell them to. After a bit of work, he managed to find a source.

The next challenge is reverse engineering the actual algorithm used by the commercial sensor. It’s challenging. A simple mixture of water and glucose, for example, made the sensor throw an error. He’ll get it eventually, though, making this a great entry for the Hackaday Prize.

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