It feels like it doesn’t matter where you go, health systems are struggling. In the US, just about any procedure is super expensive. In the UK and Australia, waiting lists extend far into the future and patients are left sitting in ambulances as hospitals lack capacity. In France, staff shortages rage furiously, frustrating operations.
It might seem like hope is fruitless and there is little that can be done. But amidst this horrid backdrop, one London hospital is finding some serious gains with some neat optimizations to the way it handles surgery, as The Times reports.
If there’s one thing which probably unites all of Hackaday’s community, it’s a love of technology. We live to hear about the very latest developments before anyone else, and the chances are for a lot of them we’ll all have a pretty good idea how they work. But if there’s something which probably annoys a lot of us the most, it’s when we see a piece of new technology misused. A lot of us are open-source enthusiasts not because we’re averse to commercial profit, but because we’ve seen the effects of monopolistic practices distorting the market with their new technologies and making matters worse, not better. After all, if a new technology isn’t capable of making the world a better place in some way, what use is it?
It’s depressing then to watch the same cycle repeat itself over and over, to see new technologies used in the service of restrictive practices for short-term gain rather than to make better products. We probably all have examples of new high-tech products that are simply bad, that are new technology simply for the sake of marketing, and which ultimately deliver something worse than what came before, but with more bling. Perhaps the worst part is the powerlessness, watching gullible members of the public lapping up something shiny and new that you know to be flawed, and not being able to do anything about it.
Here at Hackaday though, perhaps there is something I can do about it. I don’t sit in any boardroom that matters but I do have here a soapbox on which to stand, and from it I can talk to you, people whose work takes you into many fascinating corners of the tech industry and elsewhere. If I think that new technologies are being used irresponsibly to create bad products, at least I can codify how that might be changed. So here are my four Rules For The Responsible Use Of New Technology, each with some examples. They should each be self-evident, and I hope you’ll agree with me. Continue reading “A Few Reasonable Rules For The Responsible Use Of New Technology”→
We’ve made it through another trip around the sun, and for the first time in what feels like far too long, it seems like things went pretty well for the hackers and makers of the world. Like so many, our community suffered through a rough couple of years: from the part shortages that made building even the simplest of devices more expensive and difficult than it should have been, to the COVID-mandated social distancing that robbed us of our favorite meetups. But when looking back on the last twelve months, most of the news was refreshingly positive.
Pepperoni costs ten bucks, but they can’t activate Windows on their registers…
Oh sure, a trip to to the grocery store can lead to a minor existential crisis at the register, but there’s not much we at Hackaday can do about that other than recommend you some good hydroponics projects to help get your own home farm up and running.
As has become our New Year tradition, we like to take this time to go over some of the biggest stories and trends that we picked up on from our unique vantage point. Some will be obvious, but there’s always a few that sneak up on us. These posts tend to make for interesting reading in the future, and if you’ve got the time, we’d recommend going back and reading the previous entries in this series and reminiscing a bit.
It’s also a good time to reflect on Hackaday itself — how we’ve grown, the things that have changed, and perhaps what we can do better going forward. Believe it or not we do read all of the feedback from the community, whether it’s in the comments of individual posts or sent into us directly. We couldn’t do this without readers like you, so please drop us a line and let us know what you’re thinking.
So before we get any farther into 2024, let’s wind back the clock and revisit some of the highlights from the previous year.
Last time, we looked at some powerful trigger modes found on many modern scopes, including the Rigol DHO900 series we used as an example. Those triggers were mostly digital or, at least, threshold-based. This time, we’ll look at some more advanced analog triggers as well as a powerful digital trigger that can catch setup and hold violations. You can find the Raspberry Pi code to create the test waveforms online.
In addition to software, you’ll need to add some simple components to generate the analog waveform. In particular, pin 21 of the Pi connects to 2uF capacitor through a 10K resistor. The other side of the capacitor connects to ground. In addition, pin 22 connects directly to the capacitor, bypassing the 10K resistor. This allows us to discharge the capacitor quickly. The exact values are not especially important.
Runt Triggers
A runt pulse is one that doesn’t have the same voltage magnitude as surrounding pulses. Sometimes, this is due to a bus contention, for example. Imagine if you have some square waves that go from 0 to 5V. But, every so often, one pulse doesn’t make it to 5V. Instead, it stops at 3V.
What’s the most thrilling part of rocketry? Well, the liftoff, naturally. But what about the sweet anticipation in those tense moments leading up to liftoff? In other words, the countdown. Where did it come from?
Far from being simply a dramatic device, the countdown clock serves a definite purpose — it lets the technicians and the astronauts synchronize their actions during the launch sequence. But where did the countdown — those famed ten seconds of here we go! that seem to mark the point of no return — come from? Doesn’t it all seem a little theatrical for scientists?
It may surprise you to learn that neither technicians nor astronauts conceived of the countdown. In their book, “Lunar Landings and Rocket Fever: Rediscovering Woman in the Moon”, media scholars Tom Gunning and Katharina Loew reveal that a little-known Fritz Lang movie called Woman In the Moon both “predicted the future of rocketry” and “played an effective role in its early development”.
Data retention is a funny thing. Atmel will gladly tell you that the flash memory in an ATmega32A will retain its data for 100 years at room temperature. Microchip says its EEPROMs will retain data for over 200 years. And yet, humanity has barely had a good grasp on electricity for that long. Heck, the silicon chip itself was only invented in 1958. EEPROMs and flash storage are altogether younger themselves.
How can these manufacturers make such wild claims when there’s no way they could have tested their parts for such long periods of time? Are they just betting on the fact you won’t be around to chastise them in 2216 when your project suddenly fails due to bit rot.
Well, actually, there’s a very scientific answer. Enter the practice of accelerated wear testing.
Will Rogers once said that veterinarians are the best doctors because their patients can’t tell them where it hurts. I’ve often thought that electronic people have a similar problem. In many cases, what’s wrong with our circuits isn’t visible. Sure, you can visually identify a backward diode, a bad solder joint, or a blown fuse. But you can’t look at a battery and see that it is dead or that a clock signal isn’t reaching some voltage. There are lots of ways to look at what’s really going on, but there is no substitute for a scope. It used to be hard for the average person to own a scope, but these days, it doesn’t require much. If you aren’t shopping for the best tech or you are willing to use it with a PC, oscilloscopes are quite affordable. If you spend even a little, you can now get scopes that are surprisingly capable with features undreamed of in years past. For example, many modern scopes have a dizzying array of triggering options. Do you need them? What do they do? Let’s find out.
I’ll be using a relatively new Rigol DHO924S, but none of the triggering modes are unique to that instrument. Sometimes, they have different names, and, of course, their setup might look different than my pictures, but you should be able to figure it out.
What is Triggering?
In simple terms, an oscilloscope plots time across the X-axis and voltage vertically on the Y-axis. So you can look at two peaks, for example, and measure the distance between them to understand how far apart they are in time. If the signal you are measuring happens repeatedly — like a square or sine wave, for example — it hardly matters which set of peaks you look at. After all, they are all the same for practical purposes.
Pretty square waves all in a row. Channel 2 is 180 degrees out of phase (inverted). But is that all there is?
The problem occurs when you want to see something relative to a particular event. Basic scopes often have level triggering. They “start” when the input voltage goes above or below a certain value. Suppose you are looking at a square wave that goes from 0 V to 5 V. You could trigger at about 2.5 V, and the scope will never start in the middle of a cycle.
Digital scopes tend to capture data before and after the trigger, so the center of the screen will be right on an edge, and you’ll be able to see the square waves on either side. The picture shows two square waves on the screen with the trigger point marked with a T in the top center of the display. You can see the level in the top bar and also marked with a T on the right side of the screen.
What happens if there are no pulses on the trigger source channel? That depends. If you are in auto mode, the scope will eventually get impatient and trigger at random. This lets you see what’s going on, but there’s no reference. If you are in normal mode, though, the scope will either show nothing or show the last thing it displayed. Either way, the green text near the top left corner will read WAIT until the trigger event occurs. Then it will say T’D.
