The USB-C standard with its smaller connector has so far mostly escaped this trend, though this might be about to change thanks to the work of [Sam Ettinger]. His own description of his USB-C connector using a flexible PCB and a BGA-packaged ATTiny84A microcontroller is “cursed”, but we can’t decide whether or not it should also be called “genius”.
Key to this inspired piece of connector fabrication is the realization that the thickness of BGA and flex PCB together comes to the required 0.7 mm. The BGA provides the necessary stiffness, and though it’s a one-sided connector it fits the space perfectly. There are several demo boards as proofs-of-concept, and the whole lot can be found in a GitHub repository.
A furry companion robot that can purr? For me, a roboticist who can’t have pets, my newest bot will make the winter months so much more cozy! I’ve designed this module in KiCad to provide a soothing purring interaction, complementing my Companion Core. It runs on 5V and can power two or four haptic vibration motors.
Many devices have a USB-C connector to charge or power them. This is very convenient given the popularity of USB-C, its reversible cable design, and sturdy, compact design.
However, some devices will not draw power when using a USB-C-to-C cable connected to a spec-compliant charger, but will when using a USB-A-to-C cable. The USB-C specification requires upstream facing ports (UFPs), the port of the device receiving power, to connect pull-down resistors to the configuration channel (CC) pins. These missing pull-down resistors are a common reason why devices can draw power with A-to-C cables but not C-to-C ones.
Wouldn’t it be great to be able to add these resistors and enable USB-C-to-C power? This mod does just that. It is a small flex PCB with pads for two 5.1kohm pull-down resistors between CC1 and CC2, respectively, and GND.
This is a mod to add USB-C-to-C charging to devices without it. Very impressed by @oshpark's flex PCB service. The PCB needs to be dead accurate to solder to the USB connector pins (0.3mm wide) and the installed mod works perfectly.
Trill Flex brings flexible touch sensing to your maker projects. Trill Flex comes with a one-axis multitouch sensor printed on flexible PCB, but we designed this sensor to be detachable so you can create entirely custom sensors perfectly suited to your own projects.
In this tutorial we will create a custom 30-button flexible touchpad. You will learn how to set up a KiCad project and include the Trill design files, draw the pads, add a ground plane, and get your design ready to be printed. (Every purchase of Trill Flex comes with a unique discount code for $20 off flex PCB printing with our friends at OSHPark.com.)
This flexible PCB is designed to a test battery like a CR2032 coincell. The board has cutouts to allow it to fold over the positive and negative terminals and, if the battery has a enough voltage, turn on a LED:
The LED and resistor footprints are 0603 surface mount
Joey Castillo is one of those makers that not only seems to have a myriad projects continuously on the go, but also seems to actually make significant progress on them, rather than getting overwhelmed from juggling them in the air — something I’ve been known to end up doing…
With a striking resume of work that includes the Open Book, the Hiking Log, and even the more somber Big Board of Death, he’s no stranger to the pages at Hackster.io!
Keeping in following with Castillo’s focus on projects that monitor health metrics, his latest work tracks that theme perfectly, but also scales down the size of the hardware to something intended to fit within the form factor of a ring!
the big fail so far: for some reason the SPI Flash chip isn't working, so I don't have room for both the LIS3DH and Dotstar libraries. this is why I'm just running a rainbow demo, instead of reacting to motion like I'd hoped. Anyway. I'm sure I can figure it out. to be continued! pic.twitter.com/kue0Jkp4wO
— joey #voteforthedemocrat castillo (@josecastillo) October 23, 2020
The work of one such research project caught the eye of Greg Davill recently, when a paper written by Fereshteh Shahmiri and Paul H Dietz was published, after being submitted for the 2020 ACM Conference on Human Factors in Computing Systems (CHI 2020).
This paper goes by the title of “ShArc:A Geometric Technique for Multi-Bend/Shape Sensing,’ and proposes a novel contour sensor, comprised of a flexible, capacitive PCB sensor, a suitable capacitance-to-digital converter, and some subsequent signal processing, allowing a two-layer polyamide FPC circuit to cleverly capture the contours of the shape it is stuck to.
That’s the operation in a nutshell, so why are we covering all this here on Hackster? Well, it’s all about accessibility! This research isn’t relegated to labs where we’ll never see sight of it, until commercialized into a product. Far from it. Davill has shown just how easily we here at home can play along with this project, using the same tools and services that we’d normally look at for our own hobby projects!
He’s not only managed to recreate the capacitance to digital converter needed for this application, but perhaps more of note, he’s even turned his hand to having a go at the flexible sensor electrodes themselves, all fabricated by the one stop shop, whose services seem to keep on growing— our favorite board fab house, OSH Park!
OSH Park 