At least they’re forward about it - I’ve lost count of how many bike accessories claimed to be USB C, but they only charge when connected to their specialized cable that converts from USB A to C.

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hnuser123456 3 hours ago | parent [-]

Double-sided USB-C connections require a handshake before sending voltage. USB-A ports can have the 5v line active at all times. Cheap USB C gadgets often don't make the handshake, they just use it as a 5V input, necessitating an A to C cable.

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hdgvhicv 19 minutes ago | parent | next [-]

One of the many deficiencies of usb-c (who knows what power your cable supports, charger supports, if you accessory will charge, of it will connect at all)

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alacritas0 2 hours ago | parent | prev | next [-]

If you add 5.1kΩ pulldown resistors on the CC lines for USB-C, you can get the standard 5V without a handshake although current may be limited by some chargers without negotiation.

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vscode-rest 3 hours ago | parent | prev [-]

Interesting. Does UsBC spec/licensing require any sort of notation for products that don’t implement handshake?

	▲	bmicraft 3 hours ago \| parent [-]
		There is no handshake, all that's needed are two 5.1 kΩ pulldown resistors. By omitting them the manufacturer saved all of about 0.1c and made their device incompatible with compliant usb-c chargers. More info: https://hackaday.com/2023/02/07/all-about-usb-c-manufacturer...