OK here is the image of the device and it is working, like users posted. There is one problem though, I cannot buy it anywhere.

Android Auto splitter

I want to make it out of cables directly, without using the board. I need a help for this to work. I already tried it and I have a problem recognizing a phone connected to PC, there is no connection because VBUS is not connected to USB A side of the connector. I cannot connect it because PD Fast charging is supplying greater voltage on VBUS than 5V while charging.

My cables

There is also a PD Buddy Wye adapter available on the internet but it is using all 3 Type C cables. The trick there is to use pull down 5.1kom resistors from CC1 and CC2 lines without using VBUS lines. But I need to use USB 2.0 A connector which doesn't have CC1 and CC2.

PD Buddy Wye

I also tried to add resistors on the A side from this schematic below, but with no luck. When the phone is not connected to cable I get PC to recognize that something is plugged into it, and device is malfunctioning because no phone is connected. When I connect phone, the PC doesn't recognize anything at all.

D+ voltage with phone connected is around 1V, and without phone connected is around 3.6V.

Can you help me assemble this cable to work?

USB Pull Up

  • \$\begingroup\$ please post a picture of the underside of the adapter board \$\endgroup\$
    – jsotola
    May 7, 2021 at 0:24
  • \$\begingroup\$ I cannot find it anywhere. If I had the picture, I would have made it already. I need someone who bought it to take a picture of the underside. \$\endgroup\$
    – milan2105
    May 7, 2021 at 6:55

1 Answer 1


I realize this is super late but here you go.

Front of PCB
enter image description here

Source: https://drive.google.com/file/d/1lNSFo98YPnIDXND4Qn_iBad3ARNuq-qy/view?usp=sharing

Back of PCB
enter image description here

Source: https://drive.google.com/file/d/1ZK-GyNmtFY7PMOH447v0NOixivBW2coe/view?usp=drive_link

How I think the wiring diagram is enter image description here

Source: https://drive.google.com/file/d/1YGVctT_YS0jwWicaVV7MVvnb9A0Bo4ks/view?usp=sharing

I just can not confirm if the diagram is correct this is how it should be wired I traced it out but I am not 100% sure as I need someone who knows more than me about USB C standards to build a cable or replicate this board. You'll notice I have no USB ports I desoldered them to figure out the diagram as there are lines that run under the ports.

  • 1
    \$\begingroup\$ The D- can't connect to CC1 and D+ can't connect to SBU. There must be an error in the diagram. \$\endgroup\$
    – Justme
    Dec 15, 2023 at 7:41

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