I face a problem with making custom PCB with STM32F103C8T6 FS CDC but whole story looked like this.
- I've made small test app using CubeMX and IAR on cheap PC from china with same MCU - in terminal on windows I was able to receive data. BTW I used 8MHz XTAL, 1k5 pull up to 3.3 on DP line no serial resistors.
- On custom board same code (which I can download to MCU without any problem) and I'm getting Unknown Device in HW Manager on win7.
Same MCU same application and clocks and two different behaviors - what I'm doing wrong?