multichar_input module

Non-blocking multi-character numeric input handler for serial interfaces.

Provides a generator-based input routine for reading floating-point numbers from a MicroPython serial port (USB_VCP or UART). Designed for use with the cooperative multitasking scheduler: the generator yields on every loop iteration so other tasks continue to run while waiting for user input.

Supported input:

  • Digits 0–9, optional leading -, optional single .

  • Backspace / rubout (0x7F) to delete the last character

  • Enter / Return (\r or \n) to submit

multichar_input.multichar_input(ser)[source]

Generator that reads a floating-point number from a serial port.

Accumulates characters one at a time, echoes valid input back to the terminal, and returns the parsed value when the user presses Enter. Yields None on every iteration to cooperate with the task scheduler.

Args:
ser: MicroPython serial object (USB_VCP or UART) that supports

any(), read(n), and write(s).

Yields:

None: Relinquishes the CPU on every loop so other tasks can run.

Returns:

float: The value entered by the user when Enter is pressed. None: If the user presses Enter with an empty buffer (no change).