ESP-SDR Can Now Transmit

October 13, 2026 by 29 Comments

Well, that was fast! Last week, we reported on two apparently simultaneous hacks using the 2.4 GHz radio inside many ESP32 variants that enabled raw access to the radio samples, turning it into a listen-only software defined radio (SDR) platform. Listen only? That’s only half of the SDR story.

Last weekend, [marble] got started fixing that, and released an early version of ESP32 firmware that can also transmit, and got receive working with gqrx. The demo communicates between an S3 and a C6 using a Hellschreiber mode, something that’s certainly out of the WiFi spec. And it didn’t stop there, either. [marble] is working on 802.15.4 modulation at the moment, which means that maybe soon your ESP32 will speak ZigBee.

This is all in the roughly 2.4 GHz band, but [marble] suggests that it might be good down to 1.8 GHz. (Editor’s note: previously, we said 100 MHz, but that was incorrect.) So there is still some uncharted terrain, and it’s clear that the boundaries on the ESP-SDR are just starting to get pushed.

If the early hacks on the RTL-SDR set off a wave of hacker SDR radio experimentation, and we can only hope that this is the beginning of the ESP-SDR era. Thanks then to [marble]– and the original hacks coming from the Espargos team for kicking this all off!

Using A Waffle To Check The Health Of Your Wii U’s NAND Flash

October 13, 2026 by 14 Comments

Game consoles tend to have a weak spot or two that will take certain units out sooner than they would due to normal parts aging. In the case of the Wii U it’s the eMMC storage IC with the console’s firmware and any user data that likes to keel over, with the SK Hynix variant reportedly developing faulty cells much sooner than the Samsung and Toshiba chips. If you want to check the health of these eMMC ICs in your Wii U, you can do so easily now with the Wafel Installer project by [zer00p].

This doesn’t take much more than navigating to the wafel.xyz URL on the Wii U to launch the installer on any (unmodified) Wii U, or alternatively starting it from an SD card if you’re running a homebrew-enabled console. This can also install the Stroopwafel CFW, ISFSax and the Aroma homebrew environment, but the NAND testing option in the installer’s menu is what you want to select if you’re not into homebrew or have already cracked open the console for said sweet homebrew action.

All of this is covered in this video by [FunkyScott47], whose Wii U’s Samsung-branded eMMC is fortunately still all fine, but it shows off the variety of tests available. Unless the eMMC is already quite cooked this should take only a minute or two, so it’s pretty good for ease of mind.

With the heavily waffle, syrup and stroopwafel-coded naming scheme for these tools we can not be held responsible for a sudden case of the munchies, of course.

Continue reading “Using A Waffle To Check The Health Of Your Wii U’s NAND Flash” →

Counting The PET Bottles Needed To Make 1 Kg Of Printer Filament

October 13, 2026 by 33 Comments

In countries where PET bottles do not get slapped with an additional fee that induces you to return it for recycling and said fee back, the resulting piles of discarded bottles have led many enterprising individuals to consider using them to make their own PETG filament. One big question of course is just how much work it is to create even a single 1 kg spool of PETG, which is a question that [PETCraft] was only too happy to answer in a recent video.

With the channel owner clearly living in a country without a bottle deposit, it’s very easy to see PET bottles strewn about as trash, including multi-liter water bottles. As a very recycling-focused channel, this provides an excellent opportunity to show how they go about recycling these into filament.

The heat-smoothed water bottles, ready for cutting.
The heat-smoothed water bottles, ready for cutting.

The detailed process is covered in previous videos in the channel, but essentially they are first heat-smoothed to make them much easier to cut into thin strips. This is done with a very DIY cutter – also constructed from mostly salvaged and other common parts – before the strips are passed through the heated extruder nozzle of the DIY filament extruder before being wound onto spools.

Ultimately it took thirteen 5 liter bottles, a 10 L, two 8 L and a single 1.5 L bottle to hit the 1 kg target, which is quite an impressive amount of work. The next challenge will be to actually print with it, which will – naturally – be done with a DIY 3D printer made from salvaged parts and an Arduino board.

The good news about recycling bottles like this into filament is that basically all PET bottles will actually be PETG anyway, as the glycol adds the flexibility that’s essential in water bottles so that they do not shatter or rip easily. The real question you have to ask yourself is whether cleaning, cutting and spooling dozens of bottles is worth saving perhaps 10-20 bucks on a commercial spool of 1 kg PETG filament.

Continue reading “Counting The PET Bottles Needed To Make 1 Kg Of Printer Filament” →

The FPGA Chronicles: Ready To Probe

October 13, 2026 by 11 Comments

In the last few installments, we looked at using the Tang Nano 20K with both the GOWIN tools and some open-source tools. The open-source tools certainly had the advantage of letting you simulate and debug your design before sending it to the actual chip. However, as we’ll see, the GOWIN tools include a very easy-to-use, capable logic analyzer.

Setup

First, you’ll need a GAO config file. When you create one in the editor, you are given a number of complex options. With an active GAO file, the tool builds a logic analyzer into your design, and the file sets the trigger conditions.

Here’s a tip. You can only have one active GAO file. Sometimes you don’t want the logic analyzer. Other times you might want an alternate configuration. If you right-click almost any file in the IDE’s Design tab, you’ll see you can disable it. That gives it a big red X and excludes it from future builds. Well, at least until you enable it again. This lets you pick between multiple GAO files, or even multiple Verilog files, for a particular build (e.g., one for tests and another for production).

If you create a GAO file from scratch, it will ask you if you want “Lite Mode.” As far as I can tell, you will never want this mode. Always use Standard Mode. In addition, you nearly always want RTL mode, which shows you (mostly) the symbols you’ve defined and not the ones added during processing.

You can find the entire manual online, of course. However, the video below and the rest of the post will get you started quickly.

GAO Basics

To set up probing, we need to understand the design, so the rest of this post covers the Verilog we’ll use to test the logic analyzer feature, and you’ll see how the analyzer works in a video. Here are a few sneak peeks at what the analyzer output we’ll see at the end looks like:

The left-hand image shows the pulse that flips the LEDs, which is tricky because the sampling clock is 27 MHz. The right-hand side shows serial data and uses a slower clock specifically used for debugging.

Continue reading “The FPGA Chronicles: Ready To Probe” →

A Modern Browser For The PlayStation Portable

October 13, 2026 by 16 Comments

The Sony PlayStation Portable, better known as the PSP, is now over two decades old. In its day it was an impressive handheld gaming machine, not least because of the inclusion of wireless networking and a web browser.

We tried the browser back then, and it’s fair to say the experience was a little underwhelming. We’re thus mightily impressed at [Steve Janovitz], who has produced Tilefinch —  a modern web browser for the PSP.

Depending on the model, the PSP came with a 333 MHz MIPS32 processor, and for all but the first model, 64 MB of RAM. Powerful back in 2004,but leagues behind something that would run any modern web browser. So how’s he doing it? The answer seems to be by careful choice of software components and use of the PSP’s built-in capabilities for jobs such as video decoding. The browser engine is Lexbor for example, while JavaScript is handled by QuickJS.

We don’t have a PSP to hand so we can’t tell how it would render Hackaday or even how fast it is, but we’re suitably impressed by this project. For PSP enthusiasts it’s a game-changing browser, but for us it also points the way towards web browsing being a possibility for other platforms. As the distinction between a high-end microcontroller and a low-end SoC becomes blurred, we’re starting to see exciting new hardware emerging with devices such as Espressif’s ESP32-P4 that, on paper at least, might be capable of running this browser. Exciting times in limited hardware web browsing might be upon us.

Open Firmware Fixes Dead Onkyo AV Receivers

October 13, 2026 by 3 Comments

If you’ve been reading Hackaday for any length of time, you’ll know we love seeing hackers replacing the stock firmware on their devices with open source alternatives. Usually this is done because the open firmware offers more features, or lifts some arbitrary limitation. But if you find yourself installing OSIRIS on an Onkyo AV receiver such as the TX-NR717, it’s probably because you’re trying to bring the thing back to life.

As developer [Jokūbas] explains, certain Onkyo receivers that use the Texas Instruments D830 are known to suffer from a very specific failure — the device will power on and appear functional, but no audio will come through. When this happens, it’s either because the D830 itself has failed or the 64 MiB NAND flash chip that holds the firmware it runs is cooked. Unfortunately, replacing either component is a bit more difficult than you might expect.

Everything passes through the Texas Instruments D830. If it goes, you’ve got a problem.

If you swap the D830 with a pin-compatible chip that’s easier to find and less prone to failure, the stock firmware won’t boot. If you try to replace the NAND, you’ll find that the original software is only capable of addressing 512-byte pages, while the flash you’ll find on the market today uses 2 KiB or 4 KiB pages. In both cases, it’s OSIRIS to the rescue.

The open firmware not only supports D830 compatible chips such as the OMAP-L137, but it’s able to address modern NAND flash, making the replacement of either or both component far more practical. With fresh hardware and the new firmware installed, your Onkyo receiver should spring back to life. That said, OSIRIS isn’t feature complete yet, and truthfully the items listed as untested or not implemented on the feature list currently outnumber the entries for what actually does work. But at least it’s a start.

Of course, not all the burned out parts on your Onkyo receiver require a firmware flash to replace. Sometimes a misbehaving unit just needs to have a few of its passive components replaced.

Emulating A Floppy Drive By Emulating The Drive Itself

October 12, 2026 by 3 Comments

The Commodore 1541 is famously the floppy drive for the Commodore 64 series of 8-bit computers, and can be found with relative ease. Not so well known is its 1551 sibling — the drive made for the Commodore 16 and Plus/4 machines.

They’re particularly rare in 2026, so [Maciej Witkowiak] has made an emulator. But it’s not just modern silicon emulating the whole thing. Instead it’s the same 6510 and ROM you might have found on the original, talking to a Pi Pico emulating the drive hardware. It’s a gloriously over the top solution to the problem of emulating a disk drive, the reason being that it started life as a daughter board plugged into an original drive mainboard.

Complementing the Pico is a CPLD for glue logic, and an OLED for selecting disk images. The Pico even generates the clock and IRQ timing for the venerable 8-bit part. The ROM is 64k in size, room enough for both the original firmware and enhanced community versions. The whole thing can be found in a GitHub repository, should you wish to have a go yourself.

Long time Hackaday readers will know [Bil Herd] as one of our contributors. If you’re interested in the back story to the series of computers that included the Commodore 16, his book makes for interesting reading.