Previously, the machine.UART0 object had two meanings:
- it was the first UART on the chip
- it was the default output for println
These two meanings conflict, and resulted in workarounds like:
- Defining UART0 to refer to the USB-CDC interface (atsamd21,
atsamd51, nrf52840), even though that clearly isn't an UART.
- Defining NRF_UART0 to avoid a conflict with UART0 (which was
redefined as a USB-CDC interface).
- Defining aliases like UART0 = UART1, which refer to the same
hardware peripheral (stm32).
This commit changes this to use a new machine.Serial object for the
default serial port. It might refer to the first or second UART
depending on the board, or even to the USB-CDC interface. Also, UART0
now really refers to the first UART on the chip, no longer to a USB-CDC
interface.
The changes in the runtime package are all just search+replace. The
changes in the machine package are a mixture of search+replace and
manual modifications.
This commit does not affect binary size, in fact it doesn't affect the
resulting binary at all.
With this change, it's no longer necessary to set a specific pin mode:
it will get autodetected in the Configure() call.
Tested on an ItsyBitsy M4 with the mpu6050 example in the drivers repo.
This commit does the same thing as
https://github.com/tinygo-org/tinygo/pull/597 but for samd51 series
chips. Pin mode and pad numbers are automatically calculated from pin
numbers, returning an error if no valid pinout is possible.
Ayke van Laethem
deadprogram
sago35
BCG