Synchronously reads one byte from the System.IO.Ports.SerialPort input buffer.
The byte, cast to an int, or -1 if the end of the stream has been read.
This method reads one byte.
Use caution when using SerialPort.ReadByte and SerialPort.ReadChar together. Switching between reading bytes and reading characters can cause extra data to be read and/or other unintended behavior. If it is necessary to switch between reading text and reading binary data from the stream, select a protocol that carefully defines the boundary between text and binary data, such as manually reading bytes and decoding the data.
Because the System.IO.Ports.SerialPort class buffers data, and the stream contained in the SerialPort.BaseStream property does not, the two might conflict about how many bytes are available to read. The SerialPort.BytesToRead property can indicate that there are bytes to read, but these bytes might not be accessible to the stream contained in the SerialPort.BaseStream property because they have been buffered to the System.IO.Ports.SerialPort class.