Most modern equipment is connected over USB, and generally speaking we’re all the better for it. But that’s not to say there aren’t some advantages to using serial and parallel ports. For example, the slower and less complex protocols can be a bit easier to debug when devices aren’t communicating, which [Jeremy Cook] demonstrates in his latest project.
Looking to troubleshoot some communications problems he was having between his computer and CNC router, [Jeremy] came up with a handy little gadget that will allow him to visualize data passing through each pin of the parallel port in real-time. Even from across the room he can tell at a glance if communication is active, and with a keen eye, determine if he’s getting bi-directional traffic or not.
From a technical standpoint, this is a pretty simple project. The custom PCB is essentially just a pass-through, with an array of 3 mm LEDs and matching 10K resistors hanging off the data lines. But [Jeremy] found it to be an excellent excuse to brush up his KiCad skills. As he explains in the video after the break, this project certainly won’t impress the folks that do PCB design on a daily basis; but if you’re still learning the ropes, these are precisely the kind of projects you should be looking for.
Before any of you say it in the comments, we already know devices like this are available commercially for a few bucks. But that’s hardly the point. Things would be awfully slow around these parts if we disregarded any project that had a commercial alternative.
Continue reading “Blinkenlights For Your Parallel Port”
Augmented reality saw a huge boom a few years ago, where an image of the real world has some virtual element layer displayed on top of it. To get this effect to work, however, you don’t need a suite of software and smart devices. [elad] was able to augment a microscope with the output from an oscilloscope, allowing him to see waveforms while working on small printed circuit boards with the microscope.
The build relies on a simplified version of the Pepper’s Ghost illusion. This works by separating two images with a semi-transparent material such as glass, placed at an angle. When looking through the material, the two images appear to blend together. [elad] was able to build a box that attaches to the microscope with a projection of the oscilloscope image augmented on the view of the microscope.
This looks like it would be incredibly useful for PCBs, especially when dealing with small SMD components. The project is split across two entries, the second of which is here. In one demonstration the oscilloscope image is replaced with a visual of a computer monitor, so it could be used for a lot more applications than just the oscilloscope, too. There aren’t a lot of details on the project page though, but with an understanding of Pepper’s Ghost this should be easily repeatable. If you need more examples, there are plenty of other builds that use this technique.
Continue reading “Oscilloscope And Microscope Augmented With Ghosts”
We’ll go out on a limb and assume that anyone reading these words is probably familiar with the classic
ping command. Depending on which operating system you worship the options might be slightly different, but every variation of this simple tool does the same thing: send an ICMP echo request and wait for a response. How long it takes to get a response from the target, if it gets one at all, is shown to the user. This if often the very first step to diagnosing network connectivity issues; if this doesn’t work, there’s an excellent chance the line is dead.
But in the modern web-centric view of networking,
ping might not give us the whole picture. But nature it doesn’t take into account things like DNS lookups, and it certainly doesn’t help you determine what (if any) services the target has available to you. Accordingly, [Liu Zhiyong] has come up with a tool he calls “pingms”, which allows you to check web server latency right from your browser.
Rather than relying on ICMP, pingms performs a more realistic test. It takes the list of targets from the file “targets.js” and connects to each one over HTTP. How does it work? The code [Liu] has come up with will take each target domain name, append a random number to create a gibberish filename, and then calculate how long it takes to get a response when trying to download the file. Obviously it’s going to be getting a 404 response from the web server, but the important thing is simply that it gets the response.
With this data, [Liu] has come up with a simplistic but very slick interface which shows the user the collected data with easy to understand color-coded graphs. As interesting as it is to see how long it takes your favorite web sites or service providers to wake up and start talking, watching the colored bars hop up and down the list to sort themselves is easily our favorite part of pingms.
[Liu] has released pingms under the GPLv3 license, so if you’re looking to utilize the software for your own purposes you just need to provide a list of test targets. If you need to perform low-level diagnostics, check out this handy network tester you can build for cheap.
We all know that guy (or, in some cases, we are that guy) that can listen to a car running and say something like, “Yep. Needs a lifter adjustment.” A startup company named Augury aims to replace that skill with an iPhone app.
Aimed at commercial installations, a technician places a magnetic sensor to the body of the machine in question. The sensor connects to a custom box called an Auguscope that collects vibration and ultrasonic data and forwards it via the iPhone to a back end server for analysis. Moving the sensor can even allow the back end to determine the location of the fault in some cases. The comparison data the back end uses includes reference data on similar machines as well as historical data about the machine in question.
Continue reading “Listen Up: IPhone Hack Diagnoses HVAC”