The clock demo on display

Drive 1024×600 Pixels Via I2C With An ATtiny85

If you need to drive a big screen for a project, it’s fair to say your first thought isn’t going to be to use the ATtiny85. With just 512 bytes of RAM and 8 kilobytes of flash memory, the 8-bit micro seems a little cramped to drive, say, a 10″ screen. Yet that’s exactly what [ToSStudio] is doing with TinyTFT_LT7683: 1024 x 600 pixels of TFT goodness, over I2C no less.

With the right TFT controller, this little micro-controller can do magic.

The name kind of gives away the secret: it won’t work on just any TFT display. It’s using properties of the LT7683 display driver, though if you don’t have one of those, the RA8875 is also compatible. Those drivers can take more than just a pixel stream– a good thing, since you’d be hard pressed to get that many pixels streaming from an ATtiny. These are character/graphic display drivers, which means you can get them to draw both characters and graphics on the screen if you speak the lingo.

It’s still not blazing fast; the documentation suggests “static or moderately dynamic UIs” as the suggested use case, and a clock is of the pre-programmed examples. From that, we can surmise that you can get 1 FPS or better with this code. You’re limited both by the simple micro-controller and the bandwidth of the I2C bus, but within those limits this seems like a very powerful technique.

This isn’t the first ATtiny graphics library to blow our minds, but if you really want an impressive graphics demo from the little micro that could, you really need to race the beam.

Thanks to [Thomas Scherer] for the tip!

The Issue With Wii U Gamepads And How To Clone Them

The Wii U running Mario Kart with the Gamepad duplicating the main screen. (Credit: MattKC, YouTube)
The Wii U running Mario Kart with the Gamepad duplicating the main screen. (Credit: MattKC, YouTube)

How hard would it be to clone the Wii U gamepad, the quirky controller with its unique embedded screen? This is the question that [MattKC] faced as he noticed the complete lack of Wii U gamepad replacements from either Nintendo or third-parties, leading him down the rabbit hole of answering said question.

Although unloved and even despised in compared to the Nintendo Wii, the Wii U was a solid system in its own right. One of its interesting additions was the gamepad controller, whose screen games used for features like a private screen during multiplayer and 3DS-like map screens. Its main weakness is however that the Wii U gamepad was considered an irreplaceable part of the console, which is obviously not fun if your gamepad breaks and your console along with it.

The Wii U console and gamepad communicate via 5 GHz 802.11n WiFi, but in order to deter other parties from simply hopping onto the access point, Nintendo slightly obfuscated this WiFi standard. Specifically the WPA authentication was modified by a byte swap in the PTK, rendering every existing WiFi stack incompatible with the Wii U.

Continue reading “The Issue With Wii U Gamepads And How To Clone Them”

The Fourier transform

The Unreasonable Effectiveness Of The Fourier Transform

A talk, The Unreasonable Effectiveness of the Fourier Transform, was presented by [Joshua Wise] at Teardown 2025 in June last year. Click-through for the notes or check out the video below the break for the one hour talk itself.

The talk is about Orthogonal Frequency Division Multiplexing (OFDM) which is the backbone for radio telecommunications these days. [Joshua] tries to take an intuitive view (rather than a mathematical view) of working in the frequency domain, and trying to figure out how to “get” what OFDM is (and why it’s so important). [Joshua] sent his talk in to us in the hope that it would be useful for all skill levels, both folks who are new to radio and signal processing, and folks who are well experienced in working in the frequency domain.

If you think you’ve seen “The Unreasonable Effectiveness of $TOPIC” before, that’s because hacker’s can’t help but riff on the original The Unreasonable Effectiveness of Mathematics in the Natural Sciences, wherein a scientist wonders why it is that mathematical methods work at all. They seem to, but how? Or why? Will they always continue to work? It’s a mystery.

Hidden away in the notes and at the end of his presentation, [Joshua] notes that every year he watches The Fast Fourier Transform (FFT): Most Ingenious Algorithm Ever? and every year he understands a little more.

If you’re interested in OFDM be sure to check out AI Listens To Radio.

Continue reading “The Unreasonable Effectiveness Of The Fourier Transform”

Co-Extrusion Carbon Fiber FDM Filament Investigated

After previously putting carbon fiber-reinforced PLA filament under the (electron) microscope, the [I built a thing] bloke is back with a new video involving PLA-CF, this time involving co-extrusion rather than regular dispersed chopped CF. This features a continuous CF core that is enveloped by PLA, with a sample filament spool sent over by BIQU in the form of their CarbonCore25 filament.

In the previous video chopped CF in PLA turned out to be essentially a contaminant, creating voids and with no integration of the CF into the polymer matrix. Having the CF covered by PLA makes the filament less abrasive to print, which is a definitely advantage, but does it help with the final print’s properties? Of note is that this is still chopped CF, just with a longer fiber length (0.3-0.5 mm).

Samples of the BIQU filament were printed on a Bambu Lab H2D printer with AMS. In order to create a clean fracture surface, a sample was frozen in liquid nitrogen to make it easy to snap. After this it was coated with gold using a gold sputtering system to prepare it for the SEM.

Continue reading “Co-Extrusion Carbon Fiber FDM Filament Investigated”

DIY Grid Dip Meter Teardown

You don’t see them much anymore, but there was a time when any hobbyist who dealt with RF probably had a grid dip meter. The idea was to have an oscillator and measure the grid current as it coupled to external circuits. At resonance, the grid current would go down or dip, hence the name. In the hands of someone who knew how to use it, the meter could measure inductance, capacitance, tuned circuits, antennas, and more. [Thomas] takes a peek inside a homebrew unit from the 1950s in a recent video you can see below.

These meters often have a few things in common. They usually have a plug-in coil near the top and a big tuning capacitor. Of course, there’s also a meter. You have to pick the right coil for the frequency of interest, which both sets the oscillator frequency range and couples to the circuit under test.

Continue reading “DIY Grid Dip Meter Teardown”

Graphing Calculator Gets USB-C Upgrade

Unlike Texas Instruments, whose graphing calculators have famously not made technological improvements in decades despite keeping the same price tag, HP has made a few more modern graphing calculators in the last few years. One of which is the HP Prime which boasts hardware from the mid-2010s including an ARM processor, a color screen, and rechargeable lithium battery. But despite this updated hardware it’s still using micro-USB for data and charging. [David] wanted to fix that by giving this calculator a USB-C port.

The first steps were disassembling the calculator case and removing the micro-USB port. The PCB is glued to the LCD screen which isn’t ideal, but he was able to work on it with everything attached. The parts are small enough to need a microscope, and with a hot air station he was quickly able to remove the USB port. His replacements from a generic online retailer were able to be soldered without much effort, but there was one major complication. The new USB-C ports didn’t account for the “On The Go” mode supported by micro-USB and were shorting a pin to ground which put the calculator into “host” mode instead of acting as a device. But using the microscope and cutting a trace on the PCB disabled this mode permanently and got the calculator working properly.

As far as modernizing calculators go, it seems like the HP Prime checks a lot of boxes, with the major downside that the LCD screen and more powerful processor means that the battery needs to be charged more often than the old TI calculators. Rather than carry a dongle around everywhere, [David] found this to be a much more efficient change to his trusty HP. If you’re still stuck using TI calculators, though, there are a few ways to modernize those as well like this build which adds a lithium battery or this one which ports a few Game Boy games to the platform.

A man's gloved hand is need adjusting the valve on a cylinder, from which a clear plastic tube extends. The man's other hand is seen holding the the other end of the tube in front of a dish of burning wax, which is flaring brightly.

Testing Laughing Gas For Rocket Propellant

Nitrous oxide’s high-speed abilities don’t end with racing cars, as it’s a powerful enough oxidizer to be a practical component of rocket propellant. Since [Markus Bindhammer] is building a hybrid rocket engine, in his most recent video he built and tested a convenient nitrous oxide dispenser.

The most commercially available form of nitrous oxide is as a propellant for whipped cream, for which it is sold as “cream chargers,” basically small cartridges of nitrous oxide which fit into cream dispensers. Each cartridge holds about eight grams of gas, or four liters at standard temperature and pressure. To use these, [Markus] bought a cream dispenser and disassembled it for the cartridge fittings, made an aluminium adapter from those fittings to a quarter-inch pipe, and installed a valve. As a quick test, he fitted a canister in, attached it to a hose, lit some paraffin firelighter, and directed a stream of nitrous oxide at it, upon which it burned much more brightly and aggressively.

It’s not its most well-known attribute in popular culture, but nitrous oxide’s oxidizing potential is behind most of its use by hackers, whether in racing or in rocketry. [Markus] is no stranger to working with nitrogen oxides, including the much more aggressively oxidizing nitrogen dioxide.

Continue reading “Testing Laughing Gas For Rocket Propellant”