Custom Num Pad Does Double Duty As Macro Pad

June 8, 2021 by Kristina Panos 7 Comments

Why buy a num pad or a macropad when you can build something new and beautiful, open source that bad boy, and be a hero to the community? We think that should be all the justification you ever need to build instead of buy, even if you think your thing is Just Another Keypad [JAnK] as [Clewsy] claims.

At first glance, JAnK appears to be a standard number pad with four macro keys across the top. But when you roll your own ‘board, all the keys are programmable. [Clewsy] took advantage of this by adding a second layer that’s accessible with (what else?) the Num Lock key. This switches JAnK over to 21-key macro pad mode.

[Clewsy] rolled their own PCB for this and used the venerable ATMega32u4 because of its HID and USB host capabilities. Every key is backlit, and these LEDs are driven by an MP3202 LED driver and PWM from the AVR. [Clewsy] was able to build a prototype by sawing the num pad off of a stainless steel key switch plate from another build, but eventually ordered JAnK its own custom, laser-cut, stainless steel plate. The lovely enclosure is made of spotted gum wood and an acrylic base.

Putting it all together proved to be a bit problematic. [Clewsy] soldered up the minimum viable components for testing and discovered that the ATMega’s VCC and GND pins were both shorted. This killed the AVR programmer, but not the chip itself, and [Clewsy] happened to have a spare. To add insult to injury, the Num Lock light didn’t work, but [Clewsy] was able to simply reverse the LED instead of ordering a new pile of boards. Check out the detailed write-up with code and tons of pictures over on [Clewsy]’s personal site.

One of the awesome things about this build is that [Clewsy] was able to re-use the code from macr0, which began life as a proof of concept for scanning key matrices, and retired to become a music and media controller.

Easy USB‑C Power For All Your Devices

April 21, 2021 by Anool Mahidharia 28 Comments

[Mansour Behabadi] wanted to harness the high power capability of USB-C using as simple a hardware design as possible. After some research and experimental prototyping, he designed the fpx — an easy to use USB‑C power delivery board. The fpx is an improved follow up to his earlier USB PD project fabpide2 which we featured some time back. However, practical implementation of the USB PD protocol can be a bed of thorns. Negotiating power delivery usually requires a dedicated PD controller coupled with a micro-controller for user control.

With USB PD, a USB-C port can be configured as either a source, a sink, or both and allows connected devices to negotiate up to 100 W (20 V, 5 A) of power. The fpx is based around the popular STUSB4500 PD controller, which does most of the PD heavy lifting. To program the STUSB4500, he used an ATtiny 816 micro-controller, whose UPDI programming and debugging interface consumes lower board real estate.

However, what’s a little bit different is the way the fpx is programmed — by sending binary black and white flashes from any device that can display a web page. Using light isn’t a particularly new way of programming. We’ve seen it used almost a decade back by WayneAndLayne for their Blinky PoV projects, and later by the Electric Imp’s BlinkUp app. The fpx uses a similar method to read flashes of light from a screen which are picked up by a photo-transistor connected to the ATtiny. The ATtiny then communicates with the STUSB4500 over I²C. This eliminates the requirement for special software or an IDE for programming and doesn’t need any physical cable connection. Check out [Mansour]’s blog post where he walks us through the details of how he managed to wrangle the optical programming challenge.

Many of the commercially available USB PD decoy/detector/trigger boards use either solder jumpers or a switch with an RGB LED to adjust Power Delivery Output (PDO). [Mansour]’s method may be a little more robust and reliable. The STUSB4500 can store two separate PDO values and can negotiate with a source according to its capability. If the source cannot offer either of these options, the fpx can either request for a minimal 5 V / 100 mA setting, or disable the output. The fpx is an open source project, accessible on Github. Check out the video after the break for an overview of the fpx.

Continue reading “Easy USB‑C Power For All Your Devices” →

Portrait Of A Digital Weapon

April 15, 2021 by Anool Mahidharia 3 Comments

Over the years, artists have been creating art depicting weapons of mass destruction, war and human conflict. But the weapons of war, and the theatres of operation are changing in the 21^st century. The outcome of many future conflicts will surely depend on digital warriors, huddled over their computer screens, punching on their keyboards and maneuvering joysticks, or using devious methods to infect computers to disable or destroy infrastructure. How does an artist give physical form to an unseen, virtual digital weapon? That is the question which inspired [Mac Pierce] to create his latest Portrait of a Digital Weapon.

[Mac]’s art piece is a physical depiction of a virtual digital weapon, a nation-state cyber attack. When activated, this piece displays the full code of the Stuxnet virus, a worm that partially disabled Iran’s nuclear fuel production facility at Natanz around 2008. Continue reading “Portrait Of A Digital Weapon” →

Cursed USB-C: When Plug Orientation Matters

March 22, 2021 by Maya Posch 71 Comments

One of the selling points of the USB-C plug is that supposedly there is no way to incorrectly insert it. As [Pim de Groot] shows with a ‘Cursed USB-C 2.0 Device‘, reality is a bit more complicated when it comes to USB 2.0 compatibility in USB-C. He made a PCB that elegantly demonstrates the simplicity of the problem, featuring two LEDs. Only one orientation of the USB-C plug will cause one of the LEDs to light up green, with the other orientation leaving both LEDs blinking red.

Sigil on the back of the cursed USB-C 2.0 device, by Pim de Groot.

The reason for this behavior is simple: as [Pim] explains, although the USB-C plug has only a single pair of data lines (D+/-) for USB 2.0 connectivity, the receptor duplicates these on either side of its pins, leading out two pairs of D+/- lines. Normally you would connect the matching lines in these pairs together to ensure consistent behavior no matter the plug orientation, but you don’t have to.

By leading each USB 2.0 data pair to its own SAMD11C MCU, only one of the MCUs would be connected to USB, resulting in the connected MCU blinking the LEDs. With a bit more circuitry it’s possible to detect which way around the plug is inserted and use this information in a single MCU system, altering its behavior. While at first glance this seems little more than a fun party trick, but it also offers insight in a possible failure mode of USB-C 2.0 devices where only one plug orientation works, due to broken traces or pads.

Board view of [Pim]’s Cursed USB-C 2.0 Device.

(Heading image: Cursed USB-C 2.0 Device, by Pim de Groot)

A FLIR One Pro Sees Again, Thanks To Some Nifty Soldering

March 2, 2021 by Jenny List 28 Comments

The Flir One Pro is a thermal camera that attaches to a mobile phone with a USB-C plug. [Gigawatts] has one, and unfortunately managed to drop it, breaking the USB-C plug and rendering the device useless. The plug is separate from the main PCB, an assembly of its own with a flexible cable, but FLIR are not interested in supplying spares. What was the answer? Wire data lines into the device’s charging port, of course!

The One Pro has its own battery, and to avoid draining the phone it is charged through another USB connection, this time a socket. The data lines aren’t connected, which necessitated some very careful soldering of wire-wrap wire to an SMD package to fix. When completed and secured with glue the resulting camera works with a USB-C cable, and there are plans to mount a tripod thread receptacle in the space left by the USB-C plug.

It’s disappointing that Flir choose not to supply replacements for the USB-C plug assembly, seemingly they see the device as a throwaway piece of consumer electronics rather than the expensive instrument that it is. This modification should at lease allow some unfortunate One Pro owners to revive their dead cameras.

If you’re curious about the Flir One series of cameras, perhaps you’d like to read our review.

DIY USB-C Touch Monitor Is All Polished Brass

February 25, 2021 by Danie Conradie 17 Comments

We’ve known for a while that you can buy interface boards to turn old laptop screens into standalone monitors, but complete sets with 4K panels and control boards are also now becoming widely available on sites like eBay and AliExpress, and prices are dropping. These sets are also available with low-profile connectors like micro HDMI and USB-C, which allow for some very compact builds.

[Matt] from [DIY Perks] used one of these sets to build a slimline USB-C monitor with a brass enclosure. Video after the break. The enclosure consists of brass sheets and U-channel pieces soldered and screwed together. There is quite a bit of residue and discoloration after soldering, but this was removed with a bit of sanding and polishing. A pair of adjustable legs were added to allow it to stand on its own, and an additional chamber on the back holds the control board, an old smartphone battery, and a battery protection circuit. [Matt] also added a pair of removable speakers, which are sealed speaker units covered in brass mesh and plate.

We’ve covered several DIY monitor builds over the years, and they are perfect as an additional monitor for a laptop, or for pairing with the Raspberry Pi 400 with its integrated keyboard. We really [Matt]’s builds, which include a smartphone-based 4K projector, and a very effective cooling system for an expensive DSLR camera. Continue reading “DIY USB-C Touch Monitor Is All Polished Brass” →

Google-Inspired USB-PD Sniffer For The DIY Crowd

February 20, 2021 by Tom Nardi 11 Comments

If you want to hack around with the communication protocol that USB Power Delivery devices use to negotiate their power requirements with the upstream source, a tool like Google’s Twinkie really helps. With it you can sniff data off the line, analyze it, and even inject your own packets. Luckily for us, the search giant made the device open source so we can all have one of our own.

Unfortunately, as [dojoe] found out, the Twinkie isn’t particularly well suited for small-scale hobbyist manufacturing. So he came up with a revised design he calls Twonkie that replaces the six layer PCB with a much more reasonable four layer version that can be manufactured cheaply by OSHPark, and swaps out the BGA components with QFP alternatives you can hand solder.

That said, it’s still likely to be a challenging build for the home gamer. There’s quite a few 0402 passives on there, and while those are doable with an iron, it can certainly be tricky. To take some pressure off, [dojoe] says he tried to optimize the board layout as much as possible for hand assembly. He was even able to avoid needing hot air by straddling the PCB with USB-C mounts intended for vertical applications.

Given the current chip shortage, [dojoe] says the biggest problem might actually getting your hands on the STM32F072CB microcontroller at the Twonkie’s core. To that end, the board supports TQFP44 and QFN44 footprints, and you can even use a STM32F072C8 at the cost of some functionality. With a bit of luck, hopefully you can find a chip that will work in the parts bin.