One of our favorite hacker-scavengers on YouTube, [The Post-Apocalyptic Inventor], has been connecting his Raspberry Pi up to nearly every display that he’s got in his well-stocked junk pile. (Video embedded below.)
Modern monitors with an HDMI input connect right up to the Pi. Before HDMI came VGA, but the Pi doesn’t do that natively. One solution is to use a composite-to-VGA converter and pull the composite signal out of the audio jack. Lacking the right 4-pole audio cable, [TPAI] soldered some RCA plugs directly onto the Pi, and plugged that into the converter. On a yet-older monitor, he faced a SCART adapter. If you’re European, you’ll know these — it’s just composite video with a different connector. Good thing he had a composite video signal already on hand.
The pièce de resistance, though, was attaching the Pi to his 1980 Vega TV set. It only had an antenna-in connector, so he needed an RF modulator. With a (presumably) infinite supply of junk VCRs on hand, he pulled an upconverter out of the pile, and got the Pi working with the snazzy retro TV.
Continue reading “Send a Raspberry Pi Back in Time to 1980”
So you’ve built out your complete home automation setup, with little network-connected “things” scattered all around your home. You’ve got net-connected TVs, weather stations, security cameras, and whatever else. More devices means more chances for failure. How do you know that they’re all online and doing what they should?
[WTH]’s solution is pretty simple: take a Raspberry Pi Zero, ping all the things, log, and display the status on an RGB LED strip. (And if that one-sentence summary was too many words for you, there’s a video embedded below the break.)
Continue reading “Colorful Display Keeps Track of Your Network”
Every year, new models of laptops arrive on the shelves. This means that old laptops usually end up in landfills, which isn’t exactly ideal. If you don’t want to waste an old or obsolete laptop, though, there’s a way to reuse at least the screen out of one. Simply grab an FPGA off the shelf and get to work.
[Martin] shows us all how to perform this feat on our own, and goes into great detail about how all of the electronics involved work. Once everything was disassembled and the FPGA was wired up, it took him a substantial amount of time just to turn the display on. From there it was all downhill: [Martin] can now get any pattern to show up on the screen, within reason. The only limit to his display now seems to be the lack of external RAM. He currently uses the setup to drive an impressive-looking clock.
This is a big step from days passed where it was next to impossible to repurpose a laptop screen. Eventually someone discovered a way to drive these displays, and now there are cheap electronics from China that can usually get a screen like this running. It’s impressive to see it done from scratch, though, and the amount of detail in the videos are a great way to understand how everything is working.
Continue reading “FPGA Drives Old Laptop Screen”
It’s not uncommon to bitbang a protocol with a microcontroller in a pinch. I2C is frequently crunched from scratch, same with simple serial protocols, occasionally complex systems like Ethernet, and a whole host of other communication standards. But VGA gets pretty tricky because of the timing requirements, so it’s less common to bitbang. [Sven] completely threw caution to the wind. He didn’t just bitbang VGA on an Arduino, but he went one step further and configured an array of 7400 logic chips to output a VGA signal.
[Sven]’s project is in two parts. In part one, he discusses choosing a resolution and setting up the timing signal. He proceeds to output a simple(-ish) VGA signal that can be displayed on a monitor using a single gate. At that point only a red image was displayed, but getting signal lock from the monitor is a great proof of concept and [Sven] moved on to more intricate display tricks.
With the next iteration of the project [Sven] talks about adding in more circuitry to handle things like frame counting, geometry, and color. The graphics that are displayed were planned out in a simulator first, then used to design the 7400 chip configuration for that particular graphic display. It made us chuckle that [Sven] reports his monitor managed to survive this latest project!
We don’t remember seeing non-programmable integrated circuits used for VGA generation before. But bitbanging the signal on an Arduino or from an SD card slot is a great test of your ability to calculate and implement precise timings with an embedded system. Give it a try!
Continue reading “Spit Out VGA with Non-Programmable Logic Chips”
Monitoring your home’s energy use is the best way to get a handle on your utility bills. After all, you can’t manage what you can’t measure! The only problem is that most home energy monitoring systems are cumbersome, complicated, or expensive. At least, until now. [Kevin] has created a new electricity meter based on Particle Photons which should alleviate all of these problems.
The Particle Photon (we get confused on the naming scheme but believe this the new version of what used to be called the Spark Core) is a WiFi-enabled development board. [Kevin] is using two, one to drive the display and one to monitor the electricity usage. This part is simple enough, each watt-hour is accompanied by a pulse of an LED on the meter which is picked up by a TLS257 light-to-voltage sensor. The display is a Nextion TFT HMI (touch screen) which is pretty well suited for this application. The data is corralled by emoncms, part of the OpenEnergyMonitor platform, which ties everything together.
For a project that has been done more than a few times, this one does a great job of keeping the price down while maintaining a great aesthetic. Make sure to check out the video below to see it in action.
Continue reading “Simplest Electricity Monitoring Solution Yet”
There are many more things to know about a battery than its voltage and current output at any given moment, and most of them can’t be measured with a standard multimeter unless you also stand there for a long time with an Excel spreadsheet. The most useful information is battery capacity, which can tell you how much time is left until the battery is fully charged or fully discharged. [TJ] set out to create a battery data harvester, and used the ubiquitous ESP8266 to make a fully-featured battery monitor.
Measuring battery capacity is pretty straightforward but it does take time. A battery is first benchmarked to find its ideal capacity, and then future voltage and current readings can be taken and compared to the benchmark test to determine the present capacity of the battery. The ESP8266 is a relatively good choice for this kind of work. Its WiFi connection allows it to report its information to a server which will store the data and make it available for the user to see.
The first page of this project details building the actual module, and the second page outlines how to get that module to communicate with the server. Once you’ve built all of this, you can use it to monitor your whole-house UPS backup system or the battery in your solar-powered truck. There is quite a bit of information available on the project site for recreating the build yourself, and there’s also a video below which shows its operation.
Continue reading “ESP8266 Keeps An Eye On Your Batteries”
[Shen] wanted an extra monitor at his desk, but not just any monitor. He wanted something particularly special and unquestionably refined. Like any super-power-possessing engineer he set out to scratch his hacking itch and was sucked into a multi-year extravaganza. For the love of everything hardware we’re glad this one came in on the weekend. If we had spent all that time drooling during a weekday we’d be so far behind.
The final product is a desktop monitor on an articulated arm. It features a Chromebook Pixel’s IPS display in a custom-crafted
case everything. The journey started out with two different LCD units, the first from a Dell L502x replacement display using a generic LVDS board. The results were meh; washed out colors and obvious pixellation, with display adjustments that left [Shen] with a grimace on his mug. Installment two was an iPad Retina display. This iteration required spinning his own boards (resulting in [Shen’s] discovery of OSH Park). Alas, 9.7″ was too small coupled with short-cable-requirements making this version a no-go.
And so we arrive at the meat and potatoes of this one. [Shen] identified the IPS LCD display on Google’s first Chromebook Pixel laptop as the object of his desire. The hack takes him through sourcing custom display cables, spinning rev after rev of his own board, and following Alice down the rabbit hole of mechanical design. Nothing marginal is good enough for [Shen], we discovered this with his project to get real audio out of a computer. He grinds away at the driver board, the case design, the control presentation, and everything else in the project until perfection was reached. This work of art will stand the test of time as a life fixture and not just an unappreciated workhorse.
This one is not to me missed. Head over to [Shen’s] project entry on Hackaday.io (don’t forget to give him a skull for this) and his blog linked at the top. We need to celebrate not only the people who can pull off such amazing work. But also the ones who do such a great job of sharing the story both for our enjoyment, and to inspire us.