13-11-2024, 03:17 PM
(This post was last modified: 13-11-2024, 03:19 PM by Mike Watterson.)
The USB charger can do 9, 12, 15 or 20V. The default without signalling from the gadget is 5V. It need not be USB-C on the charger, some use USB-A.
Also some USB C charging schemes need USB 3.x wiring, which is FIVE EXTRA connections on a USB-A (at front of socket or back of plug). But some 12V charging via USB can use just 4 wires. Many older PC USB 3.0 ports, (USB-A or USB-C) only supply 5V.a
Many USB-C to USB-C cables are cheap USB 2.x and only have 4 wires.
It gets worse.
There at least two main specs and versions of then as to how to have more than 5V. Even regular USB has different passive signalling methods to indicate the charger can supply more than USB 1.x currents, such as 500mA 1A, 1.5A and 2A. Usually resistors or voltages on the D- and D+ pin.
In contrast USB 3.0 (which can use other than USB-C) isn't just faster data, but a separate serial port to negotiate charging,
It gets worse.
USB C audio can be simply USB digital data on D- and D+ (Needing a DAC and ADC), or some wires can be analogue audio to directly drive earphones and possibly allow a mic. But the analog feature is optional. You can't have both at the same time.
It gets worse.
USB C video can be simply USB digital data to a USB video adaptor. Or is can be USB DP, a kind of HDMI/DP digital video that uses the extra serial wires. It's very optional, and I've only one USB device that does it. Then a monitor can use USB-C for power and digital video.
It gets worse
Some gadgets even with micro or mini USB could be a host using a special passive adaptor, so a phone or tablet could use a keyboard or USB memory stick. Very few could then charge at same time, instead providing power. USB-C also has USB2go etc, and has it more often. Also more often, but not always an adaptor cable can also charge the device. Some PC USB-C (few) allow select of client or host mode, and in theory some phones/tablets can let one end be host and the other be client.
USB has had networking via USB data for maybe decades. Few gadgets support it. Some like reMarkable eink PDF reader only do networking on USB. There might even be ethernet on a USB-C cable now.
USB 1.0 was a missed opportunity. Subsequent versions are faster, handle more power and even non-USB signals. It's now a mess. It's opaque when reviewing advert to see exactly what functions are supported.
The cables are a mess too. A USB 3.0 cable (C to C, A to C, A to B are all supported) needs extra wires and the USB A port should be blue with 5 extra connections. Most USB-C to C or A to C cables sold seem to be only USB1.x/USB2.x.
Also some USB C charging schemes need USB 3.x wiring, which is FIVE EXTRA connections on a USB-A (at front of socket or back of plug). But some 12V charging via USB can use just 4 wires. Many older PC USB 3.0 ports, (USB-A or USB-C) only supply 5V.a
Many USB-C to USB-C cables are cheap USB 2.x and only have 4 wires.
It gets worse.
There at least two main specs and versions of then as to how to have more than 5V. Even regular USB has different passive signalling methods to indicate the charger can supply more than USB 1.x currents, such as 500mA 1A, 1.5A and 2A. Usually resistors or voltages on the D- and D+ pin.
In contrast USB 3.0 (which can use other than USB-C) isn't just faster data, but a separate serial port to negotiate charging,
It gets worse.
USB C audio can be simply USB digital data on D- and D+ (Needing a DAC and ADC), or some wires can be analogue audio to directly drive earphones and possibly allow a mic. But the analog feature is optional. You can't have both at the same time.
It gets worse.
USB C video can be simply USB digital data to a USB video adaptor. Or is can be USB DP, a kind of HDMI/DP digital video that uses the extra serial wires. It's very optional, and I've only one USB device that does it. Then a monitor can use USB-C for power and digital video.
It gets worse
Some gadgets even with micro or mini USB could be a host using a special passive adaptor, so a phone or tablet could use a keyboard or USB memory stick. Very few could then charge at same time, instead providing power. USB-C also has USB2go etc, and has it more often. Also more often, but not always an adaptor cable can also charge the device. Some PC USB-C (few) allow select of client or host mode, and in theory some phones/tablets can let one end be host and the other be client.
USB has had networking via USB data for maybe decades. Few gadgets support it. Some like reMarkable eink PDF reader only do networking on USB. There might even be ethernet on a USB-C cable now.
USB 1.0 was a missed opportunity. Subsequent versions are faster, handle more power and even non-USB signals. It's now a mess. It's opaque when reviewing advert to see exactly what functions are supported.
The cables are a mess too. A USB 3.0 cable (C to C, A to C, A to B are all supported) needs extra wires and the USB A port should be blue with 5 extra connections. Most USB-C to C or A to C cables sold seem to be only USB1.x/USB2.x.
