USB-C should be the power cord of the future: Engineering troubles are slowing adoption

Complexity of transitioning designs can prevent adoption of USB-C, but the proliferation of single-use AC adapters contributes to e-waste.

Your new Raspberry Pi 4 won't power on? USB-C cable problem now officially confirmed The Raspberry Pi's co-creator Eben Upton says that not every USB-C cable will power the Pi.

When USB-C was introduced in 2014, it was heralded as the solution everyone needed to the quantum USB problem—every time you plug in a USB device, the plug is the wrong side up, but somehow still wrong even after rotating it. USB-C was also designed to be sufficiently flexible to deliver power to devices—the (now-discontinued) 12-inch MacBook attempted to address all the power and connectivity needs of users with a single USB-C port.

Despite the best of intentions, USB-C adoption is still tragically uneven five years later. Data support for USB-C is messy, with eight different types of cables standardized. Proper support for power via USB-C eluded the Raspberry Pi Foundation, with initial batches of the Raspberry Pi 4 incompatible with USB-C cables designed with power capabilities in mind.

"A smart charger with an e-marked cable will incorrectly identify the Raspberry Pi 4 as an audio adapter accessory, and refuse to provide power," said Ebon Upton , co-creator of Raspberry Pi. 

SEE: 16 top laptops for business users in 2019 (free PDF) (TechRepublic)

Similarly, the early days of USB-C were tarnished with non-standard cables, leading enthusiasts and professionals to seek out the advice of Benson Leung, a Google engineer who quickly became the standard-bearer for USB-C following a series of reviews on Amazon identifying potentially dangerous non-standard cables.

"That problem, the USB compatibility problem, is not just a Type-C issue; it's been around since day one. There have always been cheap, rogue cables not up to spec," said Mark Fu, senior marketing director at Cypress Semiconductor. "There's always been devices that never passed certification, or even cases where most devices have a USB logo, but they don't interoperate, and therefore, in a debug session it'll kind of get in a shouting match. 'I'm compliant.' 'So am I.' 'I have a logo.' 'So do I.' How come they don't work?"

USB-C, when implemented to standard in a device and manufacturer-agnostic way, should be the leading standard for the electronics industry. Under optimal circumstances, USB-C should be capable of powering nearly anything, reducing the production of single-use adapters in existence. 

A universal power connector should add convenience, reduce waste

"I have an Amazon Echo. I moved it from my living room to my bedroom. For some reason, in that 20 feet of walking, I lost my power adapter," Fu said. After finding a replacement adapter on Amazon, the length of the disclaimer was alarming. "'This power adapter is for Echo and second-generation Fire TV; is not for any other Amazon speaker; is not for the first generation Fire TV.' These are products from the same manufacturer, and of the same category of devices, consume almost the same or similar amount of power. Why wouldn't you use just one power adapter?'" Fu asked.

These similar, though mutually incompatible power adapters, presents an e-waste issue. The typical lifespan of these smart home devices is between 2 and 4 years, though, with single-use adapters, the e-waste generated by these can add up quickly.

Road warriors acutely understand the difficulties that power adapters present. When traveling for business, there's a stack of electronics that make the journey with you—a notebook PC and smartphone at a minimum, with other accessories such as wireless headphones, cameras, electric razors, or others, depending on your needs. Charging these devices adds a second device to your bag, and the bulk adds up quickly.

Difficulties device manufacturers face in adding USB-C

In theory, USB-C should be an obvious choice for most electronics. USB Type-C can deliver 100W, 20V at 5 amps, which covers a wide variety of electronics. However, implementing power delivery on USB-C is not as straightforward as using dumb barrel-and-pin connections. "To enable power delivery on a Type-C port requires money. You have to put on extra silicon because it elevates power, power protection, device is higher powered, [you need a] low-side switch, MOSFET to turn on and off the power, extra components to regulate that power, the speed of turning on and turning off the power," Fu said. "So it's a bill of materials/cost trade-off."

For budget-constrained hardware hackers building their own electronics, the added complexity does not need to put USB-C out of reach for homebrew designs. Cypress' EZ-PD (Power Delivery) kit is aimed at designers looking to transition their designs, providing a USB Type-C connector that provides power to a terminal block, to which a pin-and-barrel connector can be connected.

For more. check out "You can deploy Wi-Fi 6 now, but benefits of 5G could be years away for your organization" and "Intel officially unveils Chaco Canyon, first fanless NUC in five years" on TechRepublic.

Also see

USB Type C socket

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