The USB OTG FS controller in the F401/F411 is severely crippled, as it support only 3 USB Endpoints per direction, which makes it impossible to implement more than 1 USB CDC interface (1 Bulk IN and 1 Interrupt IN required per interface).
The L4xx support 6 endpoints per direction, so up to 3 USB CDC could be supported, or a variety of other compositions.
The L4xx are mostly pin compatible with the F401/F411 (and are fully compatible with the BlackPill schematic).
Given the BluePill+ (which does not have these restrictions) is completely unavailable, this would be very welcome.
The USB OTG FS controller in the F401/F411 is severely crippled, as it support only 3 USB Endpoints per direction, which makes it impossible to implement more than 1 USB CDC interface (1 Bulk IN and 1 Interrupt IN required per interface).
The L4xx support 6 endpoints per direction, so up to 3 USB CDC could be supported, or a variety of other compositions.
The L4xx are mostly pin compatible with the F401/F411 (and are fully compatible with the BlackPill schematic).
Given the BluePill+ (which does not have these restrictions) is completely unavailable, this would be very welcome.