Reading serial data in realtime in Python

You can use inWaiting() to get the amount of bytes available at the input queue.

Then you can use read() to read the bytes, something like that:

While True:
    bytesToRead = ser.inWaiting()
    ser.read(bytesToRead)

Why not to use readline() at this case from Docs:

Read a line which is terminated with end-of-line (eol) character (\n by default) or until timeout.

You are waiting for the timeout at each reading since it waits for eol. the serial input Q remains the same it just a lot of time to get to the “end” of the buffer, To understand it better: you are writing to the input Q like a race car, and reading like an old car 🙂

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