re-enumerate USB on STM32F103

[Treacy Yao]

CDC function run normally. But if MCU reboot(For example, USB connect to PC and reboot MCU), USB will not recongnized. It will return to normal if I remove USB then insert it again.

So I want to add re-enumerate function to let device re-enumerate though USB always in PC.

1. How to modify the code to realize re-enumerate function?
2. I try to set PA12 low to high before USB init. Device cannot run. Maybe blocking

[Uwe Bonnes · Accepted solution]

If you want a work-around that is not standard compliant, switch PA12 to GPIO/Open Drain, set it low for about 10 ms, and than set up USB. This works for Bl*ckm*gic debug probes.

[Treacy Yao]

I tried. But if I add low PA12 to my code（MX_GPIO_Init）. Then my FW cannot run. I don't know why

[waclawek.jan]

> Then my FW cannot run.

What does it mean? Debug. Find out, what does it exactly do.

JW