Why Is Continuous Glucose Monitoring So Hard?

Everyone starts their day with a routine, and like most people these days, mine starts by checking my phone. But where most people look for the weather update, local traffic, or even check Twitter or Facebook, I use my phone to peer an inch inside my daughter’s abdomen. There, a tiny electrochemical sensor continuously samples the fluid between her cells, measuring the concentration of glucose so that we can control the amount of insulin she’s receiving through her insulin pump.

Type 1 diabetes is a nasty disease, usually sprung on the victim early in life and making every day a series of medical procedures – calculating the correct amount of insulin to use for each morsel of food consumed, dealing with the inevitable high and low blood glucose readings, and pinprick after pinprick to test the blood. Continuous glucose monitoring (CGM) has been a godsend to us and millions of diabetic families, as it gives us the freedom to let our kids be kids and go on sleepovers and have one more slice of pizza without turning it into a major project. Plus, good control of blood glucose means less chance of the dire consequences of diabetes later in life, like blindness, heart disease, and amputations. And I have to say I think it’s pretty neat that I have telemetry on my child; we like to call her our “cyborg kid.”

But for all the benefits of CGM, it’s not without its downsides. It’s wickedly expensive in terms of consumables and electronics, it requires an invasive procedure to place sensors, and even in this age of tiny electronics, it’s still comparatively bulky. It seems like we should be a lot further along with the technology than we are, but as it turns out, CGM is actually pretty hard to do, and there are some pretty solid reasons why the technology seems stuck.

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Anderson’s Water Computer Spills The Analog Secrets Of Digital Logic

One of the first things we learn about computers is the concept of binary ones and zeroes. When we dig into implementation of digital logic, we start to learn about voltages, and currents, and other realities of our analog world. It is common for textbooks to use flow of water as an analogy to explain flow of electrons, and [Glen Anderson] turned that conceptual illustration into reality. He brought his water computer to the downtown Los Angeles Mini Maker Faire this past weekend to show people the analog realities behind their digital devices.

[Glen]’s demonstration is a translation of another textbook illustration: binary adder with two four-bit inputs and a five-bit output. Each transistor is built from a plastic jewel box whose lid has been glued to the bottom to form two chambers. A ping-pong ball sits in the upper chamber, a rubber flap resides in the lower chamber covering a hole, with a string connecting them so a floating ball would lift the flap and expose the hole.

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Fail Of The Week: How Not To Electric Vehicle

If you ever doubt the potential for catastrophe that mucking about with electric vehicles can present, check out the video below. It shows what can happen to a couple of Tesla battery modules when due regard to safety precautions isn’t paid.

The video comes to us by way of [Rich], a gearhead with a thing for Teslas. He clearly knows his way around the EV world, having rebuilt a flood-soaked Tesla, and aspires to open an EV repair shop. The disaster stems from a novelty vehicle he and friend [Lee] bought as a side project. The car was apparently once a Disney prop car, used in parades with the “Mr. Toad’s Wild Ride” theme. It was powered by six 6-volt golf cart batteries, which let it maintain a stately, safe pace on a crowded parade route. [Rich] et al would have none of that, and decided to plop a pair of 444-cell Tesla modules into it. The reduced weight and increased voltage made it a real neck-snapper, but the team unwisely left any semblance of battery management out of the build.

You can guess what happened next, or spin up to the 3:00 mark in the video to watch the security camera mayhem. It’s not clear what started the fire, but the modules started cooking off batteries like roman candles. Quick action got it pushed outside to await the fire department, but the car was a total loss long before they showed up. Luckily no other cars in the garage were damaged, nor were there any injuries – not that the car didn’t try to take someone out, including putting a flaming round into [Lee]’s chest and one into the firetruck’s windshield.

[Rich] clearly knew he was literally playing with fire, and paid the price. The lesson here is to respect the power of these beefy batteries, even when you’re just fooling around.

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GBA Consolizer Kit RetroRGB

GBA On The Big Screen: FPGA Delivers HDMI And Every Feature Imaginable

The concept of creating a gaming portable out of a home console has been around for some time, but it’s hardly seen the other way around. There have been a few devices that dared to straddle the line (i.e., Sega Nomad, Nintendo Switch, etc.), but the two worlds typically remain separate. [Stephen] looked to explore that space by attempting to turn the Game Boy Advance into a “big boy” console. The FPGA-based mod kit he created does just that, and comes complete with controller support and digital video output in 720p over a mini HDMI cable.

The kit itself was designed specifically for the original model GBAs containing the 40-pin LCD ribbon cable. These original models were the early run of non-backlit screens that are also denoted by a motherboard designation that can be seen by peering into the battery compartment. RGB signals are read directly from the GBA LCD socket by removing the handheld’s screen in favor of a fresh flat flex ribbon cable. This method enables a noise-free digital-to-digital solution as opposed to the digital-to-analog output of Nintendo’s own Game Boy Player add-on for the GameCube.

At an astonishing 240×160 native resolution, GBA video is scaled by the FPGA up to 5x within a 720p frame. Of course some of the image is cutoff in the process, so options for 4x and 4.5x scales were included. As a wise man once said, “Leave no pixel behind”. Since Nintendo designed the GBA clock to run at 59.7276 Hz, [Stephen] removed the oscillator crystal in order to sync the refresh rate to a more HDMI friendly 60 Hz. This means that the mod kit overclocks GBA games ever so slightly, though [Stephen] included a GBA cycle accurate mode as an option if your display can handle it.

The video below is [Stephen]’s initial test using a SNES controller. Tests must have gone well, because he decided to incorporate a SNES controller port in the final design. Now all those Super Nintendo ports on the GBA are back home once again thanks to this “consolizer” kit.

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Keep Both Hands On The Probes With This Oscilloscope Footswitch

We’ve got two hands, so it’s natural to want to use both of them while diagnosing a circuit with an oscilloscope. Trouble is, keeping both hands on the probes makes it a touch difficult to manipulate the scope. If only there were some way to put your idle lower appendages to work.

This multipurpose oscilloscope footswitch interface makes so much sense that we wonder why such a thing isn’t standard equipment on more scopes. [Paul Roukema]’s interface relies on the USB Test and Measurement Class (USBTMC) protocol that allows most modern scopes to be remotely controlled, somewhat like the General Purpose Interface Bus (GPIB) protocol of old. [Paul]’s interface uses an STM32 microcontroller to talk USBTMC to either Keysight’s Infinium scopes or the Tektronix DPO line, since those were what he had to test against. Tapping the footswitch cycles the acquisition mode on and off or triggers a single acquisition. He’s thoughtfully included the USBTMC specs in his GitHub project, so adapting it to other scopes should be straightforward. We’d even wager that older scopes with GPIB could enjoy the same handsfree control.

Have a down-market scope but still want to go handsfree? [Jenny List]’s primer on running a Rigol with Python might offer some hints on where to start.

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Hackaday Links: December 2, 2018

CircuitPython is becoming a thing! CircuitPython was originally developed from MicroPython and ported to various ARM boards by Adafruit. Now, SparkFun is shipping their own CircuitPython board based on the nRF52840, giving this board an ARM Cortex-M4 and a Bluetooth radio.

You like contests, right? You like circuit boards too, right? Hackster.io now has a BadgeLove contest going on to create the Blinkiest Badge on Earth. Yes, this is a #badgelife contest, with the goal of demonstrating how much you can do in a single circuit badge. Prizes include a trip to San Francisco, a badass drone, a skateboard, a t-shirt, or socks. YES, THERE ARE SOCKS.

We have a date for the Vintage Computer Festival Pacific Northwest 2019. It’s going down March 23 and 24 at the Living Computers Museum in Seattle. The call for exhibitors is now open so head over and check it out. So far the tentative list of exhibits and presenters include Attack of the SPARC Clones, and I must mention that SPARC systems are showing up on eBay with much higher frequency lately. I have no idea why.

Need another con? How about a KiCAD con? The inaugural conference for KiCAD users is happening next April in Chicago and the call for talk proposals just opened up. The con focuses on topics like using KiCAD in a manufacturing setting, what’s going on ‘under the hood’ of KiCAD, and how to use KiCAD to make an advanced product.

Spanish police have stopped a homemade scooter. Someone, apparently, was tearing around a public road in Galacia on a homemade scooter. From the single picture, we’re going to say ‘not bad.’ It’s a gas-powered weed wacker mounted to a homemade frame.

Every year, in December, we take a look back at what Hackaday has accomplished in the past twelve months. Sure, we gave out hundreds of thousands of dollars in awards in the Hackaday Prize, and yes, we’ve pushed our coverage of tech advancements into weird, uncharted, but awesome territory. Our biggest accomplishment, though, is always how many readers we reach. This year, we had a slight fall-off in our readership in the Democratic People’s Republic of North Korea. We’re down from 156 views in 2017 to 75 views this year. While the year isn’t over, we don’t expect that number to change much. What was the cause of this drop-off? We’re not quite sure. Only time will tell, and we’re looking forward to serving fresh hacks every day to the DPRK in 2019.

A Raspberry Pi Has This Pool Covered

Far from being a tiled hole in the ground with a bit of water in it, a modern swimming pool boasts a complex array of subsystems designed to ensure your morning dip is as perfect as that you’d find on the sun-kissed beaches of your dream tropical isle. And as you might expect with such complex pieces of equipment in a domestic setting, they grow old, go wrong, and are expensive to fix.

[DrewBeer]’s pool had just such a problem. A decades-oldwired controller had failed, so rather than stump up a fortune for a refit, he created his own pool controller which exists under the watchful eye of a Raspberry Pi. The breadth of functionality is apparent from his write-up. In addition to the pump and heater you’d expect, he as a salt water system, environmental monitoring, and even an RTL-SDR to pull in readings from an RF floating temperature probe. It’s all exposed via a node.js API, and thus far has been running for over 6 months without mishap.

From where this is being written in the gloom of a damp November in a Northern Hemisphere maritime climate we can only envy [Drew] his pool and imagine it as perpetually deep blue and sparkling, invitingly cool against the heat of a summer’s day. If you have similar pool automation woes. perhaps you’d also like to look at this ESP8266 pool monitor, or another automation project using a Raspberry Pi.