If you did not assign an onData and are relying on the return of the .match()/.receive() calls, then you are using synchronous/blocking mode. The advantage to using async mode is that you don't block the Pronto UI while waiting for 300ms for data to come in.


For a serial port, you can assign callback functions such as onData, onError, onTimeout. If you do this which activates asynchronous mode, then .match() and .receive() operations do not have a return value. Instead, the data is delivered to onData by invoking your callback. In cases where a timeout occurs, the onTimeout callback function is called.

See p. 42, Section 8.2.3 Asynchronous operation

of the 1.4 version of the Dev Guide.