Serial Bluetooth get character

You should use TextReader.Read instead of TextReader.ReadLine. Basic4android - Files (Core)
Read a single character each time. You should do it in a loop while TextReader.Ready is true.

Another option which would is usually better is to use AsyncStreams instead of polling the port.

thank you

Do you have an example for AsyncStreams with a Bluetooth Connection?

regards MT

There is no real difference between using AsyncStreams with a Bluetooth connection or a TCP/IP connection. So the tutorial is relevant. There are several related threads here: Basic4android Search: AsyncStreams Bluetooth