USBPD CC orientation STM32G071RB

josemdq · ‎2024-08-15

Hi, I am troubleshooting a custom board using USBPD as sink.

It only negotiates a PDO on one orientation of the USBC connector.

Checked with an oscilloscope and I see waveform going to CC1 on the orientation that works , naturally, and changing orientation I see a waveform going to CC2 but it does not negotiate on this side.

I know the signal goes to CC2's pin. The pin is configured in STM32CubeIDE as UCPD_CC2 and set to analog mode.

The cable detection feature also does not work to detect dettach events.

Any advice appreciated. Using 4.1.0 TCPP library version.

BarryWhit · ‎2024-08-19

Good job. You should accept your own solution.

For future visitors, Section 5.1.5 "ADC configuration for VBUS reading" of AN5418 provides the details and states that monitoring VBUS with the ADC is required for correct operation of the USB state machines.

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