Return-Path: Message-ID: <4EE1213F.1090303@codeaurora.org> Date: Thu, 08 Dec 2011 12:42:39 -0800 From: Brian Gix MIME-Version: 1.0 To: mindentropy CC: linux-bluetooth@vger.kernel.org Subject: Re: Regarding setting baud rate for RFCOMM. References: <2121084.BaNgyA18vB@terranet> In-Reply-To: <2121084.BaNgyA18vB@terranet> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi mindentropy, On 12/8/2011 12:12 PM, mindentropy wrote: > How can I set the baud rate and other tty settings for RFCOMM for data > sending? The receiving application is a windows application which reads at > 115200 baud rate via virtual comm port. Baud rate does not really apply to RFCOMM in bluetooth. Baud rate refers to how fast the level shifters on a piece of UART hardware (perhaps RS232) transition between one bit to the next, while RFCOMM simply grabs data (in the case of bluez, through a pipe or socket) and sends it over the BT link at whatever rate the underlying ACL connection currently supports, which constantly is changing to based on environmental conditions. The RFCOMM transport in BT is intended to be a simplified way to migrate an existing UART based application to bluetooth. But in fact, if you were to create a UART abstraction on top of RFCOMM which did accept baud rate as a parameter, it would not matter if you set the BAUD to 300, 115200, or 921600 -- The data would flow at a rate that you would not be able to directly control. Other than that, it would generally mimic "classic" RS-232. In other words, you shouldn't need to do anything to your Windows App, as long as it is currently able to send and receive data via the virtual comm port. -- Brian Gix bgix@codeaurora.org Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum