Author: Lewin Day

3451 Articles

DIY RC Controller Built With Old-School Parts

March 20, 2024 by 16 Comments

Once upon a time, RC transmitters were expensive units that cost hundreds of dollars even at the low end. Now, you can get them pretty cheaply, or, you can choose to build your own. [Phytion] did just that.

The design isn’t based around a modern microcontroller, nor does it rely on WiFi or Bluetooth connections. Instead, it’s a little more old school. It’s built using the HT12E parallel-to-serial encoder chip, and the HT12D decoder chip for the receiver. The controller uses a pair of HT12Es on the transmitter, and a pair of HT12Ds on the receiver. These accept inputs from a pair of analog joysticks and encode them as serial data. However, they essentially just act as digital joysticks in this design. The HT12Es feed into an STX882 module which transmits the data from the HT12Es over 433 MHz. Another STX882 module receives this signal, and passes it through HT12Ds for decoding.

At the receiving end, one joystick can turn four outputs on or off depending on whether it is pushed up, down, left or right. A channel select switch then allows it to do the same for four further outputs. The second joystick just mirrors the operation of the first. It’s just intended to make controlling something like an RC car easier by allowing one stick to be pushed forwards and backwards, and the other left and right.

You don’t see many designs like this anymore. Realistically, it’s possible to get far more functionality out of a design based on an ESP32 or similar wireless-capable chip. However, this one doesn’t require any complicated handshaking and powers up instantly, which is a nice bonus. Plus, it’s always interesting to see alternative designs tried out in the wild. Video after the break.

Continue reading “DIY RC Controller Built With Old-School Parts” →

The Hunt For Alien Radio Signals Began Sooner Than You Think

March 20, 2024 by 22 Comments

Every 26 months, Earth and Mars come tantalizingly close by virtue of their relative orbits. The closest they’ve been in recent memory was a mere 55.7 million kilometers, a proximity not seen in 60,000 years when it happened in 2003.

However, we’ve been playing close attention to Mars for longer than that. All the way back in 1924, astronomers and scientists were contemplating another close fly by from the red planet. With radio then being the hot new technology on the block, the question was raised—should we be listening for transmissions from fellows over on Mars?

Continue reading “The Hunt For Alien Radio Signals Began Sooner Than You Think” →

Running Power And Data Over Just Two Wires

March 19, 2024 by 50 Comments

When you’re hooking up equipment across a vehicle, you’re often stuck sending power and data to and from things like sensors or actuators. The more wires you have to run, the more hassle, so it’s desirable to get this number as low as possible. That’s an especially big deal in the world of cycling electronics, where every additional gram is considered a drawback. To this end, companies have developed two-wire methods of sending power and data together, and now, [Keith Wakeham] has devised his own way of doing so.

[Keith] was inspired by Shimano’s E-Tube system which is fairly fancy in its encoding schemes, but he went his own way. His concept relied on old-school On-Off Keying methods to take a signal and capacitively couple a signal into power lines. He explains the theory behind the method, and shares schematics that can be used to actually communicate over power lines. Then, he shows off the real hardware that he built to test the concept for himself.

The results? Good! [Keith] was able to maintain speeds of 57,600 bits/second even with an electrically-noisy gear motor operating on the lines. That’s more then enough for all kinds of applications.

If you’ve got your own data-over-powerline hacks, don’t hesitate to let us know. Continue reading “Running Power And Data Over Just Two Wires” →

The Greenhouse Effect Isn’t For Greenhouses

March 19, 2024 by 22 Comments

Think of a greenhouse. It’s a structure with glass walls that lets light in and traps heat, all for the benefit of the plants inside. As for how it works, that’s elementary! It’s all down to the greenhouse effect… right?

Alas, no. So many of us have been mislead. Let’s rexamine how we think greenhouses work, and then explore what’s actually going on.
Continue reading “The Greenhouse Effect Isn’t For Greenhouses” →

Modern Microcontroller Boosts Classic Logic Analyzer To New Heights

March 19, 2024 by 5 Comments

[Ted Fried] recently found a beautiful HP 1600A/1607A logic analyzer set. State of the art in 1975, it looks like glorious Space Age equipment today. He decided to hook it up some modern gear to put it through its paces.

Wanting to give the equipment a proper shakedown, he enlisted a Teensy 4.1 to spit a deluge of logic at the HP unit. The microcontroller was tasked with generating 32 data signals along with two clock outputs to give the analyzer plenty to analyze. The HP 1600A handled this no problem, so [Ted] kept tinkering.

His next feat was to explore the addressable “MAP” function of the unit, which allowed writing to the 64×64 pixel display. The Teensy 4.1 was easily able to send images to the display, but [Ted] isn’t stopping there. He’s got plans to do the usual thing and get Bad Apple going on the hardware.

Getting a logic analyzer to analyze logic isn’t much of a hack, sure. But it’s instructive of how to approach working with such hardware. If you want to spit a bunch of logic out fast, a Teensy 4.1 is a great choice because it’s got a ton of IO and a ton of clock cycles to tickle it with.

We enjoyed seeing this old piece of hardware light up the phosphors once more. If you’ve got your own projects going on with classic bits of HP test gear, don’t hesitate to let us know!

Faux Silkscreen On A PCB Made With A Laser Cutter

March 18, 2024 by 13 Comments

If you’re getting PCBs professionally made, silkscreen usually comes free as part of the package. However, if you’re making your own, the job is on you. [Tony Goacher] makes his own PCBs on a CNC router, so he’s not getting any silkscreening as part of that bargain. But he wondered—could he do something analogous with a laser cutter?

The answer is yes. The silkscreen layer was first exported from DesignSpark, with the file then sent to LightBurn to prep it for laser cutting. The board outline layer was first engraved on to a piece of scrap as an alignment aid. Then, the board was placed in the laser cutter, with the silkscreen scorched directly on to the fiberglass.

The results are encouraging, if imperfect. [Tony] says he ran at “quite fast speed at quite high power.” The markings are all there, but they’re a little melty and difficult to read. He noted at lower speeds and lower power, the results were a bit more readable.

PCBs aren’t really an ideal engraving or laser marking material, but this technique could be servicable for some basic markings on DIY PCBs. We look forward to seeing how [Tony] improves the process in future. Video after the break.
Continue reading “Faux Silkscreen On A PCB Made With A Laser Cutter” →

Simple NTP Clock Uses Custom RGB 7-Segment Displays

March 17, 2024 by 14 Comments

A great majority of hackers build a clock at some point. It’s a great way to get familiar with electronics and (often) microcontrollers, and you get to express some creativity along the way. Plus, you get something useful when you’re done! [Tadas Ustinavičius] recently trod this well-worn path and built a neat little NTP clock of their own.

The build uses an ESP 12F as the core of the operation. It’s charged with querying an NTP time server via its WiFi connection in order to maintain accurate timekeeping around the clock. For display, it drives a series of custom 7-segment displays that [Tadas] built using 3D-printed housings. They use WS2812B addressable LEDs and thus can display a rainbow of colors.

For initial configuration, the phone creates its own WiFi hotspot with a web interface for changing settings. Once configured, it connects to the Internet over WiFi to query an NTP server at regular intervals.

It’s a simple build that does a simple job well. Projects like these can be very valuable, as they teach you all kinds of useful skills. If you’ve been working on your own clock design, don’t hesitate to let us know. You can use a microcontroller, relays, or even a ball.