Clearing the Serial Buffer?

[system]

You could do this:

while (Serial.available ())
  Serial.read ();

But as PaulS says, maybe just keep reading until you get the start of the next packet. For example, the datasheet says:

When communication is performed over the UART, data transmitted and received by the UM6 is formatted into packets containing:

1. The three character start sequence 's', 'n', 'p' to indicate the start of a new packet (ie. start new packet)

So just keep reading until you get 's', 'n', 'p' in sequence. You should probably do that anyway.

The UM6 will be in Listen Mode, not in Broadcast mode. Let's say that I'm polling the IMU for data from a specific register. If, for example, I receive 's' but not 'n' immediately after I may deduce that whatever data follows the initial 's' will completely useless. Similarly, if I get a Packet Type indicating a non-batch operation when I requested a batch operation, I'll want to start again. I would rather clear the entire serial buffer and ping the IMU for data again rather than burn through all the useless bytes. It will save both time and my helicopter from crashing into a wall.

I appreciate your input, but I don't think it would be safe for my project unless I am using two Arduino Unos, one to take care of motion and one dedicated to receiving/processing data.