Turning A Microchip MPLAB Snap Into A UDPI AVR Programmer

December 26, 2022 by 20 Comments

The Unified Program and Debug Interface (UPDI) is Microchip’s proprietary interface for programming and on-chip debugging, and has become the standard on AVR MCUs after Microchip’s purchase of Atmel. Being a proprietary interface means that even entry-level programmers like the Atmel-ICE are rather expensive at over $100. That’s when for [Scott W Harden] the question arose of whether the much cheaper MPLAB Snap board (~$34) could be used as well for AVR UDPI purposes.

The stages of grief that [Scott] went through before he had it working involved among others the updating of the MPLAB Snap board firmware, getting yelled at by the Microchip Studio IDE when attempting to use the Snap for AVR MCU programming, and ultimately fixing the board following the relevant Microchip Engineering Technical Note (ETN #36) that specifies the removal of a 4.7 kΩ pull-down resistor (R48) on the Snap board. This allows the UDPI line to be pulled high by the MCU.

As the ETN notes, an external pull-up may also be used to override the pull-down, which would leave the ICSP functionality of of the Snap intact. As [Scott] mentions in his conclusion, it feels as if UDPI AVR support with the Snap is really an afterthought for Microchip. Meanwhile there are also more DIY solutions as [Scott] adds, which are useful for just flashing the MCU. An example is with a USB-TTL serial adapter and pymcuprog.

The problem with DIY solutions like jtag2updi, ftdi2updi, and their kin is the effort required to assemble them, and the uncertainty of long-term support as the UPDI ecosystem keeps evolving with new devices and new features. The MPLAB Snap with resistor mod may be just that middle ground between an Atmel-ICE and reverse-engineered OSS projects.

(Featured image: MPLAB Snap resistor mod illustrated, from Microchip ETN #36)

A beige keyboard with blue and grey keys sits on a colorful deskmat atop a wooden desk. A small box with a round Touch ID button sits next to the keyboard.

Standalone Touch ID For Your Desktop Mac

December 26, 2022 by 1 Comment

With the proliferation of biometric access to mobile devices, entering a password on your desktop can feel so passé. [Snazzy Labs] decided to fix this problem for his Mac by liberating the Touch ID from a new Apple keyboard.

When Apple introduced its own silicon for its desktops, it also revealed desktop keyboards that included their Touch ID fingerprint reader system. Fingerprint access to your computer is handy, but not everyone is a fan of the typing experience on Apple keyboards. Wanting to avoid taping a keyboard under his desk, [Snazzy Labs] pulled the logic board from the keyboard and designed a new 3D printed enclosure for the Touch ID button and logic board so that the fingerprint reader could reside close to where the users hands actually are.

One interesting detail discovered was the significantly different logic boards between the standard and numpad-containing variants. The final enclosure designs feature both wireless and wired versions for both the standard and numpad logic boards if you should choose to build one of your own. We’re interested to see if someone can take this the next step and use the logic board to wire up a custom mechanical keyboard with Touch ID.

If [Snazzy Labs] seems familiar, you may recognize him from their Mac Mini Mini. If you’re more in the mood to take your security to the extreme, check out this Four Factor Biometric Lockbox that includes its own fingerprint reader.

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3D Modelling In English With AI

December 26, 2022 by 17 Comments

By now, you’ve surely seen the AI tools that can chat with you or draw pictures from prompts. OpenAI now has Point-E, which takes text or an image and produces a 3D model. You can find a few runnable demos online, but good luck having them not too busy to work.

We were not always impressed with the output. Asking for “3d printable starship Enterprise,” for example, produced a point cloud that looked like a pregnant Klingon battle cruiser. Like most of these tools, the trick is finding a good prompt. Simple things like “a chair” seemed to work somewhat better.

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An exercise bike modified to become a game controller

Pedal Your Way Through Games With This USB Exercise Bike

December 26, 2022 by 13 Comments

If you’re into cycling, there’s nothing better than heading out on the open road and feeling the wind in your hair. Unfortunately, climatic conditions make this uncomfortable or impossible at certain times of year, so you might be tempted to stay inside and play video games instead. Luckily, you can now get your gaming fix and still get in shape thanks to [Patrick]’s exercise bike game controller.

Two 3D-printed boxes with buttons and joysticks, to be attached to a bike's handlebar[Patrick] got himself a second-hand exercise bike and discovered that the speed sensor inside it was based on a magnet and reed relay, just like a regular bike computer. Reading out the sensor was therefore as simple as counting pulses using an Arduino Leonardo, and the USB HID protocol made it easy to turn the cycling mechanism into a one-dimensional game controller.

He then completed the setup by adding two 3D-printed handlebar-mounted gamepads with a few buttons and a thumbstick on each side. The total system now works as an ordinary gamepad, but with the option of using the bike as a forward/backward control.

We can imagine that this system will stay interesting for far longer than any off-the-shelf internet-connected exercise bike, because you can interface it with basically any game. [Patrick] demos his rig using first-person shooters like Doom and Team Fortress 2, but the possibilities are endless: how about turning FIFA games into bike polo? Or Mirror’s Edge into a bicycle courier adventure? After all, we’ve already seen how a similar game controller can turn Grand Theft Auto into something more like Grand Theft Bicycle.

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Self-Hosted Gaming With Friends

December 26, 2022 by 27 Comments

One of the best parts of gaming is gaming with friends, but often this requires everyone involved to have the same expensive piece of hardware. Almost everyone has a computer with a browser already, though, so if you’d like to play online with friends who don’t have the same gaming machine as you, they can play along now simply by opening a web browser thanks to this project called Qwantify.

There are a few requirements to get this to work, though. At least one person needs to have a computer with a GPU to run the docker container that hosts the game, but once that’s done anyone with a browser can connect to it and play. The entire project is open source as well, and since it’s currently a very young project there is only support for AMD and Intel GPUs but it does have a fairly intuitive user interface as well as some other features like allowing for various gaming peripherals and supporting streaming gameplay to Twitch and YouTube.

Being able to host your own gaming server is pretty common in some games like Minecraft, but we are excited to see something that is self-hosted take this idea to the next level. We haven’t seen something this ambitious since we were all talking about cloud gaming, but at least this time the games can be hosted on our own hardware.

Reverse Engineering Saves Weller With A Wonky LCD From The Trash Pile

December 25, 2022 by 15 Comments

There’s nothing more satisfying than finding a broken piece of gear in the trash and bringing it back to life. Satisfying, but also potentially more time-consuming — someone tossed it for a reason, after all. Figuring out what that reason is and finding a way to back it better is where the fun — and the peril — are.

Luckily, some pieces of equipment have a relatively short list of well-known failure modes, a fact that [Lauri Pirttiaho] relied on for this fix of an old Weller WD1 soldering station. The unit, sporting the familiar light blue Weller livery and more than a few scratches and dings, had an LCD that was DOA. Typically it’s the driver that’s the problem here, but [Lauri]’s diagnosis revealed it was the LCD module itself that was bad.

With OEM replacements being basically unobtainium at this point, the fix was to intercept the data heading from the driver to the old LCD and send it to a new, easily sourced 16×2 character LCD display. This began with an inspection of the display controller’s datasheet, and a bit of probing of the old display to find out which segments and backplanes map to which pins. A little bit of case modding allowed the new display to fit, the old controller chip was removed, and a PIC16 went into its place, in a tidy nest of Kapton tape and bodge wires. The PIC does the job of translating the original display, which had a fair number of custom icons and symbols, into sensible text-based equivalents and sending them to the 16×2 via I2C. The video below shows the hack in action; it honestly looks like it could have come from the factory like that.

The nice thing here is that [Lauri]’s fix applies to a whole range of Weller stations, so if you find one in the trash, you might be able to resuscitate it. Failing that, you could always roll your own Weller from (more-or-less) scratch.

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Laser Cut Clips Save A Lamp From The Trash

December 25, 2022 by 6 Comments

Ikea have been known for years as a purveyor of inexpensive  yet stylish homewares, but it’s fair to say that sometimes their affordability is reflected in their insubstantial construction. Such is the case with the Sjöpenna lamp, whose construction relies on rubber bands. On [Tony]’s lamp these bands degraded with age, causing it to fall apart. The solution? A set of cleverly-designed laser-cut clips to replace them.

The challenge to replacing a stretchy material with a rigid one is that it must have enough ability to bend without snapping as it is put in place. For this he selected PETG, with 0.04″ (about 1 mm thick) hitting the sweet spot. His photos demonstrate with some green tape added for visibility, how the clip bends backwards just far enough to fit over where the rubber band once located, and then flips back neatly to hold it all in place.

If you have a collapsing Ikea lamp then this will be just what you need, but this hack goes further than that. A frequent requirement for repairs is some kind of clip, because clips are always the first to break, This technique for laser cutting them is a handy one to remember, next time your design needs a springy bit of plastic.