Interpreting the results?
grymoire opened this issue · 5 comments
If a signal is missing, I'm not sure I can tell that there is a problem. It would be nice to have a chart that shows/lists the LED's that are suppose to be on for certain cable types.
A similar product has a manual, and includes a helpful guide.
C2C-caberQU PDF
Here's what page 7 shows
USB Power Delivery
- Option A: VBUS | GND | CC1 | Shield
- Option B: VBUS | GND | CC2 | Shield
USB 2.0/1.1
- Option A: VBUS | GND | D+ | D- | Shield
USB 3.0/3.1/3.2/4
- Single lane (3.0/3.1)
-- Option A: VBUS | GND | TX1+ | RX1+ | TX1- | RX1- | Shield
-- Option B: VBUS | GND | TX2+ | RX2+ | TX2- | RX2- | Shield - Dual lane (3.2/4)
-- Option A: VBUS | GND | TX1+ | RX1+ | TX1- | RX1- | TX2+ | RX2+ | TX2- | RX2- | Shield
Debug Accessory Mode
- Option A: VBUS | GND | D+ | D-| CC1 | SBU1 | TX1+ | RX1+ | TX1- | RX1- | Shield
- Option B: VBUS | GND | D+ | D-| CC2 | SBU2 | TX2+ | RX2+ | TX2- | RX2- | Shield
Alternate Mode
- Option A: VBUS | GND | TX1+ | RX1+ | TX1- | RX1- | Shield
- Option B: VBUS | GND | TX2+ | RX2+ | TX2- | RX2- | Shield
Audio Adapter Accessory Mode
- Option A: GND | CC1 | CC2 | SBU1 | SBU2 | D+ | D- | Shield
VBUS is optional for concurrent charging of a device.
It's a shame the author hasn't responded. Is that chart enough for a lowly coder to use to organize his USB cables in your opinion, @grymoire?
Wikipedia tells you what pair does and what modes it is used in. https://en.wikipedia.org/wiki/USB-C. The author is amazingly responsive when I reached out to ask about another issue. Which coincidentally someone else opened the same day (issue 18).
I gathered all of my cables and tested them. I then attached a label to each with the type of USB. And then if a cable doesn't work, I try a cable with more connections. There is an amazing number of variations in type and price, especially in USB-C cables. I have photos of a couble that might help.
This first one was an expensive cable - All lines are on exzcept for D+/D- on one side, but if you flip the USB3 cable over, the D+/D- on the other side lights up.
Now here's cable #2. I am not sure how this cable was classified. Note that how I plug it in, there are three different combination of light patterns.
Now flipping over the USB-C, note how TX2/RX2 become TX1/RX1
And now plugging into the green USB2 port instead of the blue USB3 port, we just get VBus/Gnd and D+/D-. Note we have 2 sets of Gnd/VBUS/
Here's a USB-C to USB-C cable I use for fast charging. Note it has two sets of VBus/Gnd and D+/D-, but there is also a CC2 light. If I flip the cable over, CC2 on the left changes to CC1 on the right.
And finally - a plain, ordinary USB2 data cables - with one set of VBus, ground and D+/D-.
